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  • 1. Alecian, E.
    et al.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Neiner, C.
    Wade, G. A.
    de Batz, B.
    Henrichs, H.
    Grunhut, J. H.
    Bouret, J. -C
    Briquet, M.
    Gagne, M.
    Naze, Y.
    Oksala, M. E.
    Rivinius, T.
    Townsend, R. H. D.
    Walborn, N. R.
    Weiss, W.
    First HARPSpol discoveries of magnetic fields in massive stars2011In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 536, p. L6-Article in journal (Refereed)
    Abstract [en]

    In the framework of the Magnetism in Massive Stars (MiMeS) project, a HARPSpol Large Program at the 3.6m-ESO telescope has recently started to collect high-resolution spectropolarimetric data of a large number of Southern massive OB stars in the field of the Galaxy and in many young clusters and associations. We report on the first discoveries of magnetic fields in two massive stars with HARPSpol - HD 130807 and HD 122451, and confirm the presence of a magnetic field at the surface of HD 105382 that was previously observed with a low spectral resolution device. The longitudinal magnetic field measurements strongly vary for HD 130807 from similar to-100 G to similar to 700 G. Those of HD 122451 and HD 105382 are less variable with values ranging from similar to-40 to -80 G, and from similar to-300 to -600 G, respectively. The discovery and confirmation of three new magnetic massive stars, including at least two He-weak stars, is an important contribution to one of MiMeS objectives: the understanding of the origin of magnetic fields in massive stars and their impact on stellar structure and evolution.

  • 2. Alecian, E.
    et al.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Petit, V.
    Grunhut, J.
    Landstreet, J.
    Oksala, M. E.
    Wade, G. A.
    Hussain, G.
    Neiner, C.
    Bohlender, D.
    Discovery of new magnetic early-B stars within the MiMeS HARPSpol survey2014In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 567, p. A28-Article in journal (Refereed)
    Abstract [en]

    Context. The Magnetism in Massive Stars (MiMeS) project aims at understanding the origin of the magnetic fields in massive stars as well as their impact on stellar internal structure, evolution, and circumstellar environment. Aims. One of the objectives of the MiMeS project is to provide stringent observational constraints on the magnetic fields of massive stars; however, identification of magnetic massive stars is challenging, as only a few percent of high-mass stars host strong fields detectable with the current instrumentation. Hence, one of the first objectives of the MiMeS project was to search for magnetic objects among a large sample of massive stars, and to build a sub-sample for in-depth follow-up studies required to test the models and theories of fossil field origins, magnetic wind confinement and magnetospheric properties, and magnetic star evolution. Methods. We obtained high-resolution spectropolarimetric observations of a large number of OB stars thanks to three large programs (LP) of observations that have been allocated on the high-resolution spectropolarimeters ESPaDOnS, Narval, and the polarimetric module HARPSpol of the HARPS spectrograph. We report here on the methods and first analysis of the HARPSpol magnetic detections. We identified the magnetic stars using a multi-line analysis technique. Then, when possible, we monitored the new discoveries to derive their rotation periods, which are critical for follow-up and magnetic mapping studies. We also performed a first-look analysis of their spectra and identified obvious spectral anomalies (e. g., surface abundance peculiarities, Ha emission), which are also of interest for future studies. Results. In this paper, we focus on eight of the 11 stars in which we discovered or confirmed a magnetic field from the HARPSpol LP sample (the remaining three were published in a previous paper). Seven of the fields were detected in early-type Bp stars, while the last field was detected in the Ap companion of a normal early B-type star. We report obvious spectral and multiplicity properties, as well as our measurements of their longitudinal field strengths, and their rotation periods when we are able to derive them. We also discuss the presence or absence of Ha emission with respect to the theory of centrifugally-supported magnetospheres.

  • 3. Alecian, E.
    et al.
    Neiner, C.
    Mathis, S.
    Catala, C.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Landstreet, J.
    The dramatic change of the fossil magnetic field of HD 190073: Evidence of the birth of the convective core in a Herbig star?2013In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 549, p. L8-Article in journal (Refereed)
    Abstract [en]

    In the context of the ESPaDOnS and Narval spectropolarimetric surveys of Herbig Ae/Be stars, we discovered and then monitored the magnetic field of HD 190073 over more than four years, from 2004 to 2009. Our observations all displayed similar Zeeman signatures in the Stokes V spectra, indicating that HD 190073 hosted an aligned dipole, stable over many years, consistent with a fossil origin. We obtained new observations of the star in 2011 and 2012 and detected clear variations of the Zeeman signature on timescales of days to weeks, indicating that the configuration of its field has changed between 2009 and 2011. Such a sudden change of external structure of a fossil field has never previously been observed in any intermediate or high-mass star. HD 190073 is an almost entirely radiative pre-main sequence star, probably hosting a growing convective core. We propose that this dramatic change is the result of the interaction between the fossil field and the ignition of a dynamo field generated in the newly-born convective core.

  • 4. Alentiev, D.
    et al.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Ryabchikova, T.
    Cunha, M.
    Tsymbal, V.
    Weiss, W.
    Discovery of the longest period rapidly oscillating Ap star HD1777652012In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 421, no 1, p. L82-L86Article in journal (Refereed)
    Abstract [en]

    We present the discovery of a long-period, rapidly oscillating Ap (roAp) star, HD177765. Using high-resolution time-series observations obtained with the Ultraviolet and Visual Echelle Spectrograph at the European Southern Observatory Very Large Telescope, we found radial velocity variations with amplitudes 7-150 ms(-1) and a period of 23.6 min, exceeding that of any previously known roAp star. The largest pulsation amplitudes are observed for Eu III, Ce III and for the narrow core of H alpha. We derived the atmospheric parameters and chemical composition of HD177765, showing this star to be similar to other long-period roAp stars. Comparison with theoretical pulsational models indicates an advanced evolutionary state for HD177765. Abundance analyses of this and other roAp stars suggest a systematic variation with age of the rare-earth line anomalies seen in cool Ap stars.

  • 5.
    Alvarado-Gomez, J. D.
    et al.
    European So Observ, D-85748 Garching, Germany.;Univ Munich, Univ Sternwarte Munchen, D-81679 Munich, Germany..
    Hussain, G. A. J.
    European So Observ, D-85748 Garching, Germany.;Univ Toulouse, UPS OMP, Inst Rech Astrophys & Planetol, F-31400 Toulouse, France..
    Grunhut, J.
    European So Observ, D-85748 Garching, Germany..
    Fares, R.
    INAF Osservatorio Astrofis Catania, I-95123 Catania, Italy..
    Donati, J. -F
    Alecian, E.
    UJF Grenoble 1, CNRS, INSU, IPAG,UMR 5274, Grenoble, France.;Univ Paris Diderot, UPMC, CNRS, LESIA,Observ Paris,UMR 8109, F-92190 Meudon, France..
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Oksala, M.
    Univ Paris Diderot, UPMC, CNRS, LESIA,Observ Paris,UMR 8109, F-92190 Meudon, France..
    Morin, J.
    CNRS, UMR 5299, LUPM, F-34095 Montpellier 05, France.;Univ Montpellier, F-34095 Montpellier 05, France..
    Redfield, S.
    Wesleyan Univ, Dept Astron, Van Vleck Observ, Middletown, CT 06459 USA..
    Cohen, O.
    Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA..
    Drake, J. J.
    Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA..
    Jardine, M.
    Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife, Scotland..
    Matt, S.
    Univ Exeter, Dept Phys & Astron, Exeter EX4 4SB, Devon, England..
    Petit, P.
    Univ Toulouse, UPS OMP, Inst Rech Astrophys & Planetol, F-31400 Toulouse, France.;CNRS, Inst Rech Astrophys & Planetol, F-31400 Toulouse, France..
    Walter, F. M.
    SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA..
    Activity and magnetic field structure of the Sun-like planet-hosting star HD 12372015In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 582, article id A38Article in journal (Refereed)
    Abstract [en]

    We analyse the magnetic activity characteristics of the planet-hosting Sun-like star, HD 1237, using HARPS spectro-polarimetric time-series data. We find evidence of rotational modulation of the magnetic longitudinal field measurements that is consistent with our ZDI analysis with a period of 7 days. We investigate the effect of customising the LSD mask to the line depths of the observed spectrum and find that it has a minimal effect on the shape of the extracted Stokes V profile but does result in a small increase in the S/N (similar to 7%). We find that using a Milne-Eddington solution to describe the local line profile provides a better fit to the LSD profiles in this slowly rotating star, which also affects the recovered ZDI field distribution. We also introduce a fit-stopping criterion based on the information content (entropy) of the ZDI map solution set. The recovered magnetic field maps show a strong (+90 G) ring-like azimuthal field distribution and a complex radial field dominating at mid latitudes (similar to 45 degrees). Similar magnetic field maps are recovered from data acquired five months apart. Future work will investigate how this surface magnetic field distribution affeccts the coronal magnetic field and extended environment around this planet-hosting star.

  • 6. Bagnulo, S.
    et al.
    Fossati, L.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Landstreet, J. D.
    The importance of non-photon noise in stellar spectropolarimetry The spurious detection of a non-existing magnetic field in the AO supergiant HD 922072013In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 559, p. A103-Article in journal (Refereed)
    Abstract [en]

    Context. The low-resolution, Cassegrain mounted, FORS spectropolarimeter of the ESO Very Large Telescope is being extensively used for magnetic field surveys. Some of the new discoveries suggest that relatively strong magnetic fields may play an important role in numerous physical phenomena observed in the atmospheres as well as in the circumstellar environments of certain kinds of stars. Aims. We show in detail how small instabilities or data-reduction inaccuracies represent an alternative explanation for the origin of certain signals of circular polarisation published in recent years. Methods. With the help of analytical calculations we simulate the observation of a spectral line in spectropolarimetric mode, adding very small spurious wavelength shifts, which may mimic the effects of seeing variations, rapid variations of the stellar radial velocity, or instrument instabilities. As a case study, we then re-visit the FORS2 measurements that have been used to claim the discovery of a magnetic field in the A0 supergiant HD 92207. In addition, we present new observations of this star obtained with the HARPSpol instrument. Results. Both calibration and science data show compelling evidence that photon-noise is not the only source of error in magnetic field measurements, especially in sharp spectral lines. Non-photon noise may be kept under control by accurate data reduction and quality controls. Our re-analysis of FORS2 observations of HD 92207 shows no evidence of a magnetic field, and we are able to reproduce the previous FORS detection only by degrading the quality of our wavelength calibration. Our HARPSpol spectropolarimetric measurements show no evidence of a magnetic field at the level of 10 G. Conclusions. Our work contributes to a better understanding of the importance of accurate data treatment and instrument characterisation, and demonstrates that ultra-high signal-to-noise ratio measurements do not automatically translate into ultra-high accuracy.

  • 7. Bagnulo, S.
    et al.
    Landstreet, J. D.
    Fossati, L.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Magnetic field measurements and their uncertainties: the FORS1 legacy2012In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 538, p. A129-Article in journal (Refereed)
    Abstract [en]

    Context. During the last decade, the FORS1 instrument of the ESO Very Large Telescope has been extensively used to study stellar magnetism. A number of interesting discoveries of magnetic fields in several classes of stars have been announced, many of which obtained at a similar to 3 sigma level; some of the discoveries are confirmed by measurements obtained with other instruments, some are not.

    Aims. We investigate the reasons for the discrepancies between the results obtained with FORS1 and those obtained with other instruments.

    Methods. Using the ESO FORS pipeline, we have developed a semi-automatic procedure for magnetic field determination. We have applied this procedure to the full content of circular spectropolarimetric measurements of the FORS1 archive (except for most of the observations obtained in multi-object spectropolarimetric mode). We have devised and applied a number of consistency checks to our field determinations, and we have compared our results to those previously published in the literature.

    Results. We find that for high signal-to-noise ratio measurements, photon noise does not account for the full error bars. We discuss how field measurements depend on the specific algorithm adopted for data reduction, and we show that very small instrument flexures, negligible in most of the instrument applications, may be responsible for some spurious field detections in the null profiles. Finally, we find that we are unable to reproduce some results previously published in the literature. Consequently, we do not confirm some important discoveries of magnetic fields obtained with FORS1 and reported in previous publications.

    Conclusions. Our revised field measurements show that there is no contradiction between the results obtained with the low-resolution spectropolarimeter FORS1 and those obtained with high-resolution spectropolarimeters. FORS1 is an instrument capable of performing reliable magnetic field measurements, provided that the various sources of uncertainties are properly taken into account.

  • 8. Bailey, J. D.
    et al.
    Landstreet, J. D.
    Bagnulo, S.
    Fossati, L.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Paladini, C.
    Silvester, J.
    Wade, G.
    Magnetic field and atmospheric chemical abundances of the magnetic Ap star HD 3181072011In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 535, p. A25-Article in journal (Refereed)
    Abstract [en]

    Context. A new generation of powerful and efficient spectropolarimeters has recently been used to provide the first sample of magnetic Ap stars of accurately known ages. Modelling of these data offer the possibility of significant new insights into the physics and main sequence evolution of these remarkable stars.

    Aims. New spectra have been obtained with the ESPaDOnS spectropolarimeter, and are supplemented with unpolarised spectra from the ESO UVES, UVES-FLAMES, and HARPS spectrographs, of the very peculiar large-field magnetic Ap star HD 318107, a member of the open cluster NGC 6405 and thus a star with a well-determined age. The available data provide sufficient material with which to re-analyse the first-order model of the magnetic field geometry and to derive chemical abundances of Si, Ti, Fe, Nd, Pr, Mg, Cr, Mn, O, and Ca.

    Methods. The models were obtained using ZEEMAN, a program which synthesises spectral line profiles for stars that have magnetic fields. The magnetic field structure was modelled with a low-order colinear multipole expansion, using coefficients derived from the observed variations of the field strength with rotation phase. The abundances of several elements were determined using spectral synthesis. After experiments with a very simple model of uniform abundance on each of three rings of equal width in co-latitude and symmetric about the assumed magnetic axis, we decided to model the spectra assuming uniform abundances of each element over the stellar surface.

    Results. The new magnetic field measurements allow us to refine the rotation period of HD 318107 to P = 9.7088 +/- 0.0007 days. Appropriate magnetic field model parameters were found that very coarsely describe the (apparently rather complex) field moment variations. Spectrum synthesis leads to the derivation of mean abundances for the elements Mg, Si, Ca, Ti, Cr, Fe, Nd, and Pr. All of these elements except for Mg and Ca are strongly overabundant compared to the solar abundance ratios. There is considerable evidence of non-uniformity, for example in the different values of < B(z)> found using lines of different elements.

    Conclusions. The present data set, while limited, is nevertheless sufficient to provide a useful first-order assessment of both the magnetic and surface abundance properties of HD 318107, making it one of the very few magnetic Ap stars of well-known age for which both of these properties have been studied.

  • 9. Benedict, G. Fritz
    et al.
    McArthur, Barbara E.
    Feast, Michael W.
    Barnes, Thomas G.
    Harrison, Thomas E.
    Bean, Jacob L.
    Menzies, John W.
    Chaboyer, Brian
    Fossati, Luca
    Nesvacil, Nicole
    Smith, Horace A.
    Kolenberg, Katrien
    Laney, C. D.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Nelan, Edmund P.
    Shulyak, D. V.
    Taylor, Denise
    Freedman, Wendy L.
    Distance scale zero points from galactic RR Lyrae star parallaxes2011In: Astronomical Journal, ISSN 0004-6256, E-ISSN 1538-3881, Vol. 142, no 6, p. 187-Article in journal (Refereed)
    Abstract [en]

    We present new absolute trigonometric parallaxes and proper motions for seven Population II variable stars-five RR Lyr variables: RZ Cep, XZ Cyg, SU Dra, RR Lyr, and UV Oct; and two type 2 Cepheids: VY Pyx and kappa Pav. We obtained these results with astrometric data from Fine Guidance Sensors, white-light interferometers on Hubble Space Telescope. We find absolute parallaxes in milliseconds of arc: RZ Cep, 2.12 +/- 0.16 mas; XZ Cyg, 1.67 +/- 0.17 mas; SU Dra, 1.42 +/- 0.16 mas; RR Lyr, 3.77 +/- 0.13 mas; UV Oct, 1.71 +/- 0.10 mas; VY Pyx, 6.44 +/- 0.23 mas; and. Pav, 5.57 +/- 0.28 mas; an average sigma(pi)/pi = 5.4%. With these parallaxes, we compute absolute magnitudes in V and K bandpasses corrected for interstellar extinction and Lutz-Kelker-Hanson bias. Using these RR Lyrae variable star absolute magnitudes, we then derive zero points for M(V)-[Fe/H] and M(K)-[Fe/H]-log P relations. The technique of reduced parallaxes corroborates these results. We employ our new results to determine distances and ages of several Galactic globular clusters and the distance of the Large Magellanic Cloud. The latter is close to that previously derived from Classical Cepheids uncorrected for any metallicity effect, indicating that any such effect is small. We also discuss the somewhat puzzling results obtained for our two type 2 Cepheids.

  • 10.
    Brown, A. G. A.
    et al.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Vallenari, A.
    Osserv Astron Padova, INAF, Vicolo Osservatorio 5, I-35122 Padua, Italy..
    Prusti, T.
    European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201AZ Noordwijk, Netherlands..
    de Bruijne, J. H. J.
    European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201AZ Noordwijk, Netherlands..
    Mignard, F.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Drimmel, R.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Babusiaux, C.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Bailer-Jones, C. A. L.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Bastian, U.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Biermann, M.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Evans, D. W.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Eyer, L.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Jansen, F.
    European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Operat Dept, Mission Operat Div, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Jordi, C.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Katz, D.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Klioner, S. A.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Lammers, U.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Lindegren, L.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Luri, X.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    O'Mullane, W.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Panem, C.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Pourbaix, D.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium.;FRS FNRS, Rue Egmont 5, B-1000 Brussels, Belgium..
    Randich, S.
    Osserv Astrofis Arcetri, INAF, Largo Enrico Fermi 5, I-50125 Florence, Italy..
    Sartoretti, P.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Siddiqui, H. I.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo del Castillo, Madrid 28692, Spain..
    Soubiran, C.
    Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France..
    Valette, V.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    van Leeuwen, F.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Walton, N. A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Aerts, C.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.;Radboud Univ Nijmegen, IMAPP, Dept Astrophys, POB 9010, NL-6500 GL Nijmegen, Netherlands..
    Arenou, F.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Cropper, M.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England..
    Hog, E.
    Univ Copenhagen, Niels Bohr Inst, Juliane Maries Vej 30, DK-2100 Copenhagen O, Denmark..
    Lattanzi, M. G.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Grebel, E. K.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Holland, A. D.
    Open Univ, Dept Phys Sci, Ctr Elect Imaging, Walton Hall, Milton Keynes MK7 6AA, Bucks, England..
    Huc, C.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Passot, X.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Perryman, M.
    European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201AZ Noordwijk, Netherlands..
    Bramante, L.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Cacciari, C.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Castaneda, J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Chaoul, L.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Cheek, N.
    Serco Gest Negocios ESA ESAC, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    De Angeli, F.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Fabricius, C.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Guerra, R.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Hernandez, J.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Jean-Antoine-Piccolo, A.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Masana, E.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Messineo, R.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Mowlavi, N.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Nienartowicz, K.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Ordonez-Blanco, D.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Panuzzo, P.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Portell, J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Richards, P. J.
    Rutherford Appleton Lab, STFC, Didcot OX11 0QX, Oxon, England..
    Riello, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Seabroke, G. M.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England..
    Tanga, P.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Thevenin, F.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Torra, J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Els, S. G.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany.;ESAC, Gaia DPAC Project Off, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Gracia-Abril, G.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain.;ESAC, Gaia DPAC Project Off, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Comoretto, G.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo del Castillo, Madrid 28692, Spain..
    Garcia-Reinaldos, M.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Lock, T.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Mercier, E.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany.;ESAC, Gaia DPAC Project Off, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Altmann, M.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany.;UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France..
    Andrae, R.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Astraatmadja, T. L.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Bellas-Velidis, I.
    Natl Observ Athens, Athens 15236, Greece..
    Benson, K.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England..
    Berthier, J.
    UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Blomme, R.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    Busso, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Carry, B.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France.;UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Cellino, A.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Clementini, G.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Cowell, S.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Creevey, O.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France.;Univ Paris XI, CNRS, Inst Astrophys Spatiale, UMR 8617, Batiment 121, F-91405 Orsay, France..
    Cuypers, J.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    Davidson, M.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    De Ridder, J.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium..
    de Torres, A.
    ESA ESAC, HE Space Operat BV, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Delchambre, L.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Dell'Oro, A.
    Osserv Astrofis Arcetri, INAF, Largo Enrico Fermi 5, I-50125 Florence, Italy..
    Ducourant, C.
    Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France..
    Fremat, Y.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    Garcia-Torres, M.
    Univ Pablo de Olavide, Area Lenguajes & Sistemas Informat, Ctra Utrera,Km 1, Seville 41013, Spain..
    Gosset, E.
    FRS FNRS, Rue Egmont 5, B-1000 Brussels, Belgium.;Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Halbwachs, J. -L
    Hambly, N. C.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Harrison, D. L.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.;Univ Cambridge, Kavli Inst Cosmol, Madingley Rd, Cambridge CB3 0HA, England..
    Hauser, M.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Hestroffer, D.
    UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Hodgkin, S. T.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Huckle, H. E.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England..
    Hutton, A.
    ESA ESAC, Aurora Technol, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Jasniewicz, G.
    Univ Montpellier, Lab Univers & Particules Montpellier, Pl Eugene Bataillon,CC72, F-34095 Montpellier 05, France..
    Jordan, S.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Kontizas, M.
    Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Korn, Andreas J.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Lanzafame, A. C.
    Univ Catania, Dipartimento Fis & Astron, Sez Astrofis, Via S Sofia 78, I-95123 Catania, Italy.;Osserv Astrofis Catania, INAF, Via S Sofia 78, I-95123 Catania, Italy..
    Manteiga, M.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Moitinho, A.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Muinonen, K.
    Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland.;Finnish Geospatial Res Inst FGI, Geodeetinrinne 2, Masala 02430, Finland..
    Osinde, J.
    ESA ESAC, Isdefe, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Pancino, E.
    Osserv Astrofis Arcetri, INAF, Largo Enrico Fermi 5, I-50125 Florence, Italy.;ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy..
    Pauwels, T.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    Petit, J. -M
    Recio-Blanco, A.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Robin, A. C.
    Univ Bourgogne Franche Comte, OSU THETA Franche Comte Bourgogne, CNRS, Inst UTINAM UMR6213, F-25000 Besancon, France..
    Sarro, L. M.
    UNED, Dept Inteligencia Artificial, C Juan del Rosal 16, Madrid 28040, Spain..
    Siopis, C.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium..
    Smith, M.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England..
    Smith, K. W.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Sozzetti, A.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Thuillot, W.
    UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    van Reeven, W.
    ESA ESAC, Aurora Technol, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Viala, Y.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Abbas, U.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Aramburu, A. Abreu
    ESA ESAC, Elecnor Deimos Space, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Accart, S.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Aguado, J. J.
    UNED, Dept Inteligencia Artificial, C Juan del Rosal 16, Madrid 28040, Spain..
    Allan, P. M.
    Rutherford Appleton Lab, STFC, Didcot OX11 0QX, Oxon, England..
    Allasia, W.
    EURIX Srl, Via Carcano 26, I-10153 Turin, Italy..
    Altavilla, G.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Alvarez, M. A.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Alves, J.
    Univ Vienna, Dept Astrophys, Turkenschanzstr 17, A-1180 Vienna, Austria..
    Anderson, R. I.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.;Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA..
    Andrei, A. H.
    UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France.;ON MCTI BR, Rua Gal Jose Cristino 77, BR-20921400 Rio De Janeiro, RJ, Brazil.;OV UFRJ BR, Ladeira Pedro Antonio 43, BR-20080090 Rio De Janeiro, RJ, Brazil..
    Varela, E. Anglada
    Serco Gest Negocios ESA ESAC, Camino Bajo del Castillo S-N, Madrid 28692, Spain.;ESA ESAC, Isdefe, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Antiche, E.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Antoja, T.
    European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201AZ Noordwijk, Netherlands..
    Anton, S.
    Univ Porto, Fac Ciencias, Dept Matemat, Rua Campo Alegre 687, P-4169007 Oporto, Portugal.;Univ Lisbon, Inst Astrofis & Ciencias Espaco, Fac Ciencias, P-1749016 Lisbon, Portugal..
    Arcay, B.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Bach, N.
    ESA ESAC, Aurora Technol, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Baker, S. G.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England..
    Balaguer-Nunez, L.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Barache, C.
    UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France..
    Barata, C.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Barbier, A.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Barblan, F.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Barrado y Navascues, D.
    ESA ESAC, Ctr Astrobiol CSIC INTA, Dept Astrofis, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Barros, M.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Barstow, M. A.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Becciani, U.
    Osserv Astrofis Catania, INAF, Via S Sofia 78, I-95123 Catania, Italy..
    Bellazzini, M.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Garcia, A. Bello
    Univ Oviedo, Campus Univ, Gijon 33203, Spain..
    Belokurov, V.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Bendjoya, P.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Berihuete, A.
    Univ Cadiz, Avd Univ, Cadiz 11002, Spain..
    Bianchi, L.
    EURIX Srl, Via Carcano 26, I-10153 Turin, Italy..
    Bienayme, O.
    Univ Strasbourg, Observ Astron Strasbourg, CNRS, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France..
    Billebaud, F.
    Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France..
    Blagorodnova, N.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Blanco-Cuaresma, S.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.;Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France..
    Boch, T.
    Univ Strasbourg, Observ Astron Strasbourg, CNRS, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France..
    Bombrun, A.
    ESA ESAC, HE Space Operat BV, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Borrachero, R.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Bouquillon, S.
    UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France..
    Bourda, G.
    Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France..
    Bouy, H.
    ESA ESAC, Ctr Astrobiol CSIC INTA, Dept Astrofis, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Bragaglia, A.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Breddels, M. A.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands..
    Brouillet, N.
    Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France..
    Bruesemeister, T.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Bucciarelli, B.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Burgess, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Burgon, R.
    Open Univ, Dept Phys Sci, Ctr Elect Imaging, Walton Hall, Milton Keynes MK7 6AA, Bucks, England..
    Burlacu, A.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Busonero, D.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Buzzi, R.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Caffau, E.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Cambras, J.
    Univ Catalunya, Consorci Serv, C Gran Capita 2-4 3rd Floor, Barcelona 08034, Spain..
    Campbell, H.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Cancelliere, R.
    Univ Turin, Dept Comp Sci, Corso Svizzera 185, I-10149 Turin, Italy..
    Cantat-Gaudin, T.
    Osserv Astron Padova, INAF, Vicolo Osservatorio 5, I-35122 Padua, Italy..
    Carlucci, T.
    UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France..
    Carrasco, J. M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Castellani, M.
    Osserv Astron Roma, INAF, Via Frascati 33, I-00078 Rome, Italy..
    Charlot, P.
    Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France..
    Charnas, J.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Chiavassa, A.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Clotet, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Cocozza, G.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Collins, R. S.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Costigan, G.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Crifo, F.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Cross, N. J. G.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Crosta, M.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Crowley, C.
    ESA ESAC, HE Space Operat BV, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Dafonte, C.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Damerdji, Y.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium.;CRAAG, Route Observ,BP 63 Bouzareah, Algiers 16340, Algeria..
    Dapergolas, A.
    Natl Observ Athens, Athens 15236, Greece..
    David, P.
    UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    David, M.
    Univ Antwerp, Onderzoeksgrp Toegepaste Wiskunde, Middelheimlaan 1, B-2020 Antwerp, Belgium..
    De Cat, P.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    de Felice, F.
    Univ Padua, Dept Phys & Astron, Via Marzolo 8, I-35131 Padua, Italy..
    de laverny, P.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    De Luise, F.
    Osservatorio Astron Teramo, INAF, Via Mentore Maggini, I-64100 Teramo, Italy..
    De March, R.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    de Martino, D.
    Osserv Astron Capodimonte, INAF, Via Moiariello 16, I-80131 Naples, Italy..
    de Souza, R.
    Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao,1226 Cidade Univ, BR-05508900 Sao Paulo, SP, Brazil..
    Debosscher, J.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium..
    del Pozo, E.
    ESA ESAC, Aurora Technol, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Delbo, M.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Delgado, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Delgado, H. E.
    UNED, Dept Inteligencia Artificial, C Juan del Rosal 16, Madrid 28040, Spain..
    Di Matteo, P.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Diakite, S.
    Univ Bourgogne Franche Comte, OSU THETA Franche Comte Bourgogne, CNRS, Inst UTINAM UMR6213, F-25000 Besancon, France..
    Distefano, E.
    Osserv Astrofis Catania, INAF, Via S Sofia 78, I-95123 Catania, Italy..
    Dolding, C.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England..
    Dos Anjos, S.
    Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao,1226 Cidade Univ, BR-05508900 Sao Paulo, SP, Brazil..
    Drazinos, P.
    Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Duran, J.
    ESA ESAC, Isdefe, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Dzigan, Y.
    Tel Aviv Univ, Dept Geosci, IL-6997801 Tel Aviv, Israel.;Univ Amsterdam, Astron Inst Anton Pannekoek, POB 94249, NL-1090 GE Amsterdam, Netherlands..
    Edvardsson, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Enke, H.
    Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    Evans, N. W.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Bontemps, G. Eynard
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Fabre, C.
    CNES Ctr Spatial Toulouse, ATOS, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Fabrizio, M.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.;Osservatorio Astron Teramo, INAF, Via Mentore Maggini, I-64100 Teramo, Italy..
    Faigler, S.
    Tel Aviv Univ, Sch Phys & Astron, IL-6997801 Tel Aviv, Israel..
    Falcao, A. J.
    UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal..
    Casas, M. Farras
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Federici, L.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Fedorets, G.
    Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland..
    Fernandez-Hernandez, J.
    Serco Gest Negocios ESA ESAC, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Fernique, P.
    Univ Strasbourg, Observ Astron Strasbourg, CNRS, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France..
    Fienga, A.
    Univ Nice Sophia Antipolis, Lab Geoazur, UMR 7329, CNRS,Observ Cote dAzur, 250 Rue A Einstein, F-06560 Valbonne, France..
    Figueras, F.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Filippi, F.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Findeisen, K.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Fonti, A.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Fouesneau, M.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Fraile, E.
    ESA ESAC, RHEA, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Fraser, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Fuchs, J.
    Acad Sci Czech Republic, Astron Inst, Fricova 298, Ondrejov 25165, Czech Republic..
    Gai, M.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Galleti, S.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Galluccio, L.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Garabato, D.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Garcia-Sedano, F.
    UNED, Dept Inteligencia Artificial, C Juan del Rosal 16, Madrid 28040, Spain..
    Garofalo, A.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Garralda, N.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Gavras, P.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;Natl Observ Athens, Athens 15236, Greece.;Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Gerssen, J.
    Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    Geyer, R.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Gilmore, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Girona, S.
    Barcelona Supercomp Ctr, Centro Nacl Supercomp, C Jordi Girona 29,Ed Nexus 2, Barcelona 08034, Spain..
    Giuffrida, G.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy..
    Gomes, M.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Gonzalez-Marcos, A.
    Univ La Rioja, Dept Mech Engn, C San Jose de Calasanz 31, Logrono 26004, La Rioja, Spain..
    Gonzalez-Nunez, J.
    Serco Gest Negocios ESA ESAC, Camino Bajo del Castillo S-N, Madrid 28692, Spain.;Univ Vigo, ETSE Telecomunicac, Campus Lagoas Marcosende, Vigo 36310, Galicia, Spain..
    Gonzalez-Vidal, J. J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Granvik, M.
    Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland..
    Guerrier, A.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Guillout, P.
    Univ Strasbourg, Observ Astron Strasbourg, CNRS, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France..
    Guiraud, J.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Gurpide, A.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Gutierrez-Sanchez, R.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo del Castillo, Madrid 28692, Spain..
    Guy, L. P.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Haigron, R.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Hatzidimitriou, D.
    Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Haywood, M.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Heiter, Ulrike
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Helmi, A.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands..
    Hobbs, D.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Hofmann, W.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Holl, B.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Holland, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Hunt, J. A. S.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England..
    Hypki, A.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Icardi, V.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Irwin, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    de Fombelle, G. Jevardat
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Jofre, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.;Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France..
    Jonker, P. G.
    Radboud Univ Nijmegen, IMAPP, Dept Astrophys, POB 9010, NL-6500 GL Nijmegen, Netherlands.;SRON Netherlands Inst Space Res, SRON, Sorbonnelaan 2, NL-3584 CA Utrecht, Netherlands..
    Jorissen, A.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium..
    Julbe, F.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Karampelas, A.
    Natl Observ Athens, Athens 15236, Greece.;Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Kochoska, A.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia..
    Kohley, R.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Kolenberg, K.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.;Univ Antwerp, Dept Phys, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.;Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA..
    Kontizas, E.
    Natl Observ Athens, Athens 15236, Greece..
    Koposov, S. E.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Kordopatis, G.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France.;Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    Koubsky, P.
    Acad Sci Czech Republic, Astron Inst, Fricova 298, Ondrejov 25165, Czech Republic..
    Krone-Martins, A.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Kudryashova, M.
    UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Kull, I.
    Tel Aviv Univ, Sch Phys & Astron, IL-6997801 Tel Aviv, Israel..
    Bachchan, R. K.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Lacoste-Seris, F.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Lanza, A. F.
    Osserv Astrofis Catania, INAF, Via S Sofia 78, I-95123 Catania, Italy..
    Lavigne, J. -B
    Le Poncin-Lafitte, C.
    UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France..
    Lebreton, Y.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;Univ Rennes 1, Inst Phys Rennes, F-35042 Rennes, France..
    Lebzelter, T.
    Univ Vienna, Dept Astrophys, Turkenschanzstr 17, A-1180 Vienna, Austria..
    Leccia, S.
    Osserv Astron Capodimonte, INAF, Via Moiariello 16, I-80131 Naples, Italy..
    Leclerc, N.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Lecoeur-Taibi, I.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Lemaitre, V.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Lenhardt, H.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Leroux, F.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Liao, S.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy.;Chinese Acad Sci, Shanghai Astron Observ, 80 Nandan Rd, Shanghai 200030, Peoples R China..
    Licata, E.
    EURIX Srl, Via Carcano 26, I-10153 Turin, Italy..
    Lindstrom, H. E. P.
    Univ Copenhagen, Niels Bohr Inst, Juliane Maries Vej 30, DK-2100 Copenhagen O, Denmark.;CSC Danmark AS, Retortvej 8, DK-2500 Valby, Denmark..
    Lister, T. A.
    Las Cumbres Observ Global Telescope Network Inc, 6740 Cortona Dr,Suite 102, Goleta, CA 93117 USA..
    Livanou, E.
    Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Lobel, A.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    Loeffler, W.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Lopez, M.
    ESA ESAC, Ctr Astrobiol CSIC INTA, Dept Astrofis, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Lorenz, D.
    Univ Vienna, Dept Astrophys, Turkenschanzstr 17, A-1180 Vienna, Austria..
    MacDonald, I.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Fernandes, T. Magalhacs
    UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal..
    Managau, S.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Mann, R. G.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Mantelet, G.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Marchal, O.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Marchant, J. M.
    Liverpool John Moores Univ, Astrophys Res Inst, Liverpool L3 5RF, Merseyside, England..
    Marconi, M.
    Osserv Astron Capodimonte, INAF, Via Moiariello 16, I-80131 Naples, Italy..
    Marinoni, S.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.;Osserv Astron Roma, INAF, Via Frascati 33, I-00078 Rome, Italy..
    Marrese, P. M.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.;Osserv Astron Roma, INAF, Via Frascati 33, I-00078 Rome, Italy..
    Marschalko, G.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary.;Univ Szeged, Baja Observ, Szegedi Ut 3-70, H-6500 Baja, Hungary..
    Marshall, D. J.
    Univ Paris Diderot, CEA Saclay, CEA DSM CNRS, IRFU,Serv Astrophys,Lab AIM, Bat 709, F-91191 Gif Sur Yvette, France..
    Martin-Fleitas, J. M.
    ESA ESAC, Aurora Technol, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Martino, M.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Mary, N.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Matijevic, G.
    Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    Mazeh, T.
    Tel Aviv Univ, Sch Phys & Astron, IL-6997801 Tel Aviv, Israel..
    McMillan, P. J.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Messina, S.
    Osserv Astrofis Catania, INAF, Via S Sofia 78, I-95123 Catania, Italy..
    Michalik, D.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Millar, N. R.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Miranda, B. M. H.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Molina, D.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Molinaro, R.
    Osserv Astron Capodimonte, INAF, Via Moiariello 16, I-80131 Naples, Italy..
    Molinaro, M.
    Osserv Astron Trieste, INAF, Via GB Tiepolo 11, I-34143 Trieste, Italy..
    Molnar, L.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary..
    Moniez, M.
    Univ Paris Saclay, CNRS IN2P3, Univ Paris Sud, Lab Accelerateur Lineaire, F-91898 Orsay, France..
    Montegriffo, P.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Mor, R.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Mora, A.
    ESA ESAC, Aurora Technol, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Morbidelli, R.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Morel, T.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Morgenthaler, S.
    Ecole Polytech Fed Lausanne, SB MATHAA STAP, MA B1 473,Batiment MA,Stn 8, CH-1015 Lausanne, Switzerland..
    Morris, D.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Mulone, A. F.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Muraveva, T.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Musella, I.
    Osserv Astron Capodimonte, INAF, Via Moiariello 16, I-80131 Naples, Italy..
    Narbonne, J.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Nelemans, G.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.;Radboud Univ Nijmegen, IMAPP, Dept Astrophys, POB 9010, NL-6500 GL Nijmegen, Netherlands..
    Nicastro, L.
    INAF IASF Bologna, Via P Gobetti 101, I-40129 Bologna, Italy..
    Noval, L.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Ordenovic, C.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Ordieres-Mere, J.
    Tech Univ Madrid, Jose Gutierrez Abascal 2, Madrid 28006, Spain..
    Osborne, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Pagani, C.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Pagano, I.
    Osserv Astrofis Catania, INAF, Via S Sofia 78, I-95123 Catania, Italy..
    Pailler, F.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Palacin, H.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Palaversa, L.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Parsons, P.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo del Castillo, Madrid 28692, Spain..
    Pecoraro, M.
    EURIX Srl, Via Carcano 26, I-10153 Turin, Italy..
    Pedrosa, R.
    CNES Ctr Spatial Toulouse, EQUERT Int, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Pentikainen, H.
    Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland..
    Pichon, B.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Piersimoni, A. M.
    Osservatorio Astron Teramo, INAF, Via Mentore Maggini, I-64100 Teramo, Italy..
    Pincau, F. -X
    Plachy, E.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary..
    Plum, G.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Poujoulet, E.
    CNES Ctr Spatial Toulouse, AKKA, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Prsa, A.
    Villanova Univ, Dept Astrophys & Planetary Sci, 800 E Lancaster Ave, Villanova, PA 19085 USA..
    Pulone, L.
    Osserv Astron Roma, INAF, Via Frascati 33, I-00078 Rome, Italy..
    Ragaini, S.
    Osservatorio Astron Bologna, INAF, Via Ranzani 1, I-40127 Bologna, Italy..
    Rago, S.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Rambaux, N.
    UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Ramos-Lerate, M.
    ESA ESAC, Vitrociset Belgium, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Ranalli, P.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Rauw, G.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Read, A.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Regibo, S.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium..
    Reyle, C.
    Univ Bourgogne Franche Comte, OSU THETA Franche Comte Bourgogne, CNRS, Inst UTINAM UMR6213, F-25000 Besancon, France..
    Ribeiro, R. A.
    UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal..
    Rimoldini, L.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Ripepi, V.
    Osserv Astron Capodimonte, INAF, Via Moiariello 16, I-80131 Naples, Italy..
    Riva, A.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Rixon, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Roelens, M.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Romero-Gomez, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Rowell, N.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Royer, F.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Ruiz-Dern, L.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Sadowski, G.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium..
    Selles, T. Sagrista
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Sahlmann, J.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Salgado, J.
    ESA ESAC, Isdefe, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Salguero, E.
    ESA ESAC, Isdefe, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Sarasso, M.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Savietto, H.
    Fork Res, Rua Cruzado Osberno,Lt 1,9 Esq, Lisbon, Portugal..
    Schultheis, M.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Sciacca, E.
    Osserv Astrofis Catania, INAF, Via S Sofia 78, I-95123 Catania, Italy..
    Segol, M.
    CNES Ctr Spatial Toulouse, APAVE SUDEUROPE SAS, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Segovia, J. C.
    Serco Gest Negocios ESA ESAC, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Segransan, D.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Shih, I. -C
    Smareglia, R.
    Osserv Astron Trieste, INAF, Via GB Tiepolo 11, I-34143 Trieste, Italy..
    Smart, R. L.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Solano, E.
    ESA ESAC, Ctr Astrobiol CSIC INTA, Dept Astrofis, Camino Bajo del Castillo S-N, Madrid 28692, Spain.;Spanish Virtual Observ, Granada, Spain..
    Solitro, F.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Sordo, R.
    Osserv Astron Padova, INAF, Vicolo Osservatorio 5, I-35122 Padua, Italy..
    Nieto, S. Soria
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Souchay, J.
    UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France..
    Spagna, A.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Spoto, F.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Stampa, U.
    Heidelberg Univ, Astron Rechen Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Steele, I. A.
    Liverpool John Moores Univ, Astrophys Res Inst, Liverpool L3 5RF, Merseyside, England..
    Steidelmueller, H.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Stephenson, C. A.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo del Castillo, Madrid 28692, Spain..
    Stoev, H.
    INAF, Fdn Galileo Galilei, Rambla Jose Ana Fernandez Perez 7, Brena Baja 38712, Santa Cruz De T, Spain..
    Suess, F. F.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Suveges, M.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Surdej, J.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Szabados, L.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary..
    Szegedi-Elek, E.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary..
    Tapiador, D.
    ESA ESAC, INSA, Camino Bajo del Castillo S-N, Madrid 28692, Spain.;Univ Complutense Madrid, Dept Arquitectura Comp & Automat, Fac Informat, C Prof Jose Garcia Santesmases S-N, E-28040 Madrid, Spain..
    Taris, F.
    UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France..
    Tauran, G.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Taylor, M. B.
    Univ Bristol, HH Wills Phys Lab, Tyndall Ave, Bristol BS8 1TL, Avon, England..
    Teixeira, R.
    Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao,1226 Cidade Univ, BR-05508900 Sao Paulo, SP, Brazil..
    Terrett, D.
    Rutherford Appleton Lab, STFC, Didcot OX11 0QX, Oxon, England..
    Tingley, B.
    Aarhus Univ, Stellar Astrophys Ctr, Dept Phys & Astron, 120 Ny Munkegade,Bldg 1520, DK-8000 Aarhus C, Denmark..
    Trager, S. C.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands..
    Turon, C.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Ulla, A.
    Univ Vigo, Dept Appl Phys, Vigo 36310, Spain..
    Utrilla, E.
    ESA ESAC, Aurora Technol, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Valentini, G.
    Osservatorio Astron Teramo, INAF, Via Mentore Maggini, I-64100 Teramo, Italy..
    van Elteren, A.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Van Hemelryck, E.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    van Leeuwen, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Varadi, M.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.;Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary..
    Vecchiato, A.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Veljanoski, J.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands..
    Via, T.
    Univ Catalunya, Consorci Serv, C Gran Capita 2-4 3rd Floor, Barcelona 08034, Spain..
    Vicente, D.
    Barcelona Supercomp Ctr, Centro Nacl Supercomp, C Jordi Girona 29,Ed Nexus 2, Barcelona 08034, Spain..
    Vogt, S.
    ESA ESTEC, HE Space Operat BV, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Voss, H.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Votruba, V.
    Acad Sci Czech Republic, Astron Inst, Fricova 298, Ondrejov 25165, Czech Republic..
    Voutsinas, S.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Walmsley, G.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Weiler, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Weingrill, K.
    Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    Wevers, T.
    Radboud Univ Nijmegen, IMAPP, Dept Astrophys, POB 9010, NL-6500 GL Nijmegen, Netherlands..
    Wyrzykowski, L.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.;Univ Warsaw Observ, Al Ujazdowskie 4, PL-00478 Warsaw, Poland..
    Yoldas, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Zerjal, M.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia..
    Zucker, S.
    Tel Aviv Univ, Dept Geosci, IL-6997801 Tel Aviv, Israel..
    Zurbach, C.
    Univ Montpellier, Lab Univers & Particules Montpellier, Pl Eugene Bataillon,CC72, F-34095 Montpellier 05, France..
    Zwitter, T.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia..
    Alecu, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Allen, M.
    European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201AZ Noordwijk, Netherlands..
    Prieto, C. Allende
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England.;Inst Astrofis Canarias, Tenerife 38205, Spain.;Univ La Laguna, Dept Astrofis, Tenerife 38206, Spain..
    Amorim, A.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Anglada-Escude, G.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Arsenijevic, V.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Azaz, S.
    European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201AZ Noordwijk, Netherlands..
    Balm, P.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo del Castillo, Madrid 28692, Spain..
    Beck, M.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Bernstein, H. -H
    Bigot, L.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Bijaoui, A.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Blasco, C.
    ESA ESTEC, RHEA, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Bonfigli, M.
    Osservatorio Astron Teramo, INAF, Via Mentore Maggini, I-64100 Teramo, Italy..
    Bono, G.
    Osserv Astron Roma, INAF, Via Frascati 33, I-00078 Rome, Italy..
    Boudreault, S.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England.;Max Planck Inst Solar Syst Res, Justus von Liebig Weg 3, D-37077 Gottingen, Germany..
    Bressan, A.
    SISSA, Via Bonomea 265, I-34136 Trieste, Italy..
    Brown, S.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Brunet, P. -M
    Bunclark, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Buonanno, R.
    Osserv Astron Roma, INAF, Via Frascati 33, I-00078 Rome, Italy..
    Butkevich, A. G.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Carret, C.
    CNES Ctr Spatial Toulouse, EQUERT Int, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Carrion, C.
    UNED, Dept Inteligencia Artificial, C Juan del Rosal 16, Madrid 28040, Spain..
    Chemin, L.
    Univ Bordeaux, Lab Astrophys Bordeaux, CNRS, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France.;Minist Ciencia Tecnol, Inst Nacl Pesquisas Espaciais, Ave Astronautas 1758, BR-12227010 Sao Jose Dos Campos, SP, Brazil..
    Chereau, F.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Corcione, L.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Darmigny, E.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    de Boer, K. S.
    Univ Bonn, Argelander Inst Astron, Hugel 71, D-53121 Bonn, Germany..
    de Teodoro, P.
    Serco Gest Negocios ESA ESAC, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    de Zeeuw, P. T.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands.;European Southern Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany..
    Delle Luche, C.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Domingues, C. D.
    Univ Lisbon, Lab Opt Lasers & Syst, Fac Sci, Campus Lumiar,Estr Paco Lumiar 22, P-1649038 Lisbon, Portugal..
    Dubath, P.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Fodor, F.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Frezouls, B.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Fries, A.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Fustes, D.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Fyfe, D.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Gallardo, E.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Gallegos, J.
    Serco Gest Negocios ESA ESAC, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Gardiol, D.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Gebran, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain.;Notre Dame Univ, Dept Phys & Astron, POB 72, Zouk Mikael, Lebanon..
    Gomboc, A.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia.;Univ Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia..
    Gomez, A.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Grux, E.
    Univ Bourgogne Franche Comte, OSU THETA Franche Comte Bourgogne, CNRS, Inst UTINAM UMR6213, F-25000 Besancon, France..
    Gueguen, A.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;OPINAS, Max Planck Inst Extraterr Phys, Giessenbachstr, D-85741 Garching, Germany..
    Heyrovsky, A.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Hoar, J.
    European Space Astron Ctr ESA ESAC, Camino Bajo dell Castillo S-N, Madrid 28692, Spain..
    Iannicola, G.
    Osserv Astron Roma, INAF, Via Frascati 33, I-00078 Rome, Italy..
    Parache, Y. Isasi
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Janotto, A. -M
    Joliet, E.
    ESA ESAC, HE Space Operat BV, Camino Bajo del Castillo S-N, Madrid 28692, Spain.;CALTECH, NASA IPAC Infrared Sci Arch, Mail Code 100-22,770 South Wilson Ave, Pasadena, CA 91125 USA..
    Jonckheere, A.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    Keil, R.
    Univ Bremen, Ctr Appl Space Technol & Micrograv ZARM, Fallturm 1, D-28359 Bremen, Germany.;ESA ESOC, RHEA Syst, Robert Bosch Str 5, D-64293 Darmstadt, Germany..
    Kim, D. -W
    Klagyivik, P.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary..
    Klar, J.
    Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    Knude, J.
    Univ Copenhagen, Niels Bohr Inst, Juliane Maries Vej 30, DK-2100 Copenhagen O, Denmark..
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Kolka, I.
    Tartu Observ, EE-61602 Toravere, Estonia..
    Kos, J.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia.;Univ Sydney, Sch Phys A28, Sydney Inst Astron, Sydney, NSW 2006, Australia..
    Kutka, A.
    Acad Sci Czech Republic, Astron Inst, Fricova 298, Ondrejov 25165, Czech Republic.;Slovak Org Space Activ, Zamocka 18, Bratislava 85101, Slovakia..
    Lainey, V.
    UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    LeBouquin, D.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Liu, C.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.;Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China..
    Loreggia, D.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Makarov, V. V.
    US Naval Observ, Astrometry Dept, 3450 Massachusetts Ave NW, Washington, DC 20392 USA..
    Marseille, M. G.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Martayan, C.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.;European Southern Observ, Alonso de Cordova 3107, Casilla 19001, Santiago De Chi, Chile..
    Martinez-Rubi, O.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Massart, B.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France.;CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.;Airbus Def & Space SAS, 31 Rue Cosmonautes, F-31402 Toulouse 4, France..
    Meynadier, F.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;UPMC Univ Paris 06, PSL Res Univ, CNRS, SYRTE,Observ Paris,Sorbonne Univ,LNE, 61 Ave Observ, F-75014 Paris, France..
    Mignot, S.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Munari, U.
    Osserv Astron Padova, INAF, Vicolo Osservatorio 5, I-35122 Padua, Italy..
    Nguyen, A. -T
    Nordlander, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Ocvirk, P.
    Univ Strasbourg, Observ Astron Strasbourg, CNRS, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France.;Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    O'Flaherty, K. S.
    ESA ESTEC, EJR Quartz BV, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Sanz, A. Olias
    ESA ESAC, Server Labs, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Ortiz, P.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Osorio, J.
    Univ Porto, Fac Ciencias, Dept Matemat, Rua Campo Alegre 687, P-4169007 Oporto, Portugal..
    Oszkiewicz, D.
    Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland.;Adam Mickiewicz Univ, Fac Phys, Astron Observ Inst, Ul Sloneczna 36, PL-60286 Poznan, Poland..
    Ouzounis, A.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Palmer, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Park, P.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Pasquato, E.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium..
    Peltzer, C.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England..
    Peralta, J.
    Peturaud, F.
    Univ Paris Diderot, PSL Res Univ, CNRS, GEPI,Observ Paris,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Pieniluoma, T.
    Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland..
    Pigozzi, E.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Poels, J.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Prat, G.
    CNES Ctr Spatial Toulouse, CS Syst Informat, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Prod'homme, T.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands.;European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Raison, F.
    OPINAS, Max Planck Inst Extraterr Phys, Giessenbachstr, D-85741 Garching, Germany.;ESA ESAC, Praesepe BV, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Rebordao, J. M.
    Univ Lisbon, Lab Opt Lasers & Syst, Fac Sci, Campus Lumiar,Estr Paco Lumiar 22, P-1649038 Lisbon, Portugal..
    Risquez, D.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Rocca-Volmerange, B.
    UPMC, Sorbonne Univ, F-75014 Paris, France.;Inst Astrophys Paris, CNRS, UMR7095, F-75014 Paris, France..
    Rosen, S.
    Univ Coll London, Mullard Space Sci Lab, Surrey RH5 6NT, England.;Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Ruiz-Fuertes, M. I.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Russo, F.
    Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy..
    Sembay, S.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Vizcaino, I. Serraller
    ESA ESAC, GMV, Camino Bajo del Castillo S-N, Madrid 28692, Spain..
    Short, A.
    European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201AZ Noordwijk, Netherlands..
    Siebert, A.
    Univ Strasbourg, Observ Astron Strasbourg, CNRS, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France.;Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    Silva, H.
    UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal..
    Sinachopoulos, D.
    Natl Observ Athens, Athens 15236, Greece..
    Slezak, E.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice, France..
    Soffel, M.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Sosnowska, D.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Straizys, V.
    Vilnius Univ, Inst Theoret Phys & Astron, Sauletekio Al 3, LT-10222 Vilnius, Lithuania..
    ter Linden, M.
    ESA ESAC, HE Space Operat BV, Camino Bajo del Castillo S-N, Madrid 28692, Spain.;S&T Corp, POB 608, NL-2600 AP Delft, Netherlands..
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    Southwest Res Inst SwRI, Dept Space Studies, 1050 Walnut St,Suite 300, Boulder, CO 80302 USA..
    Theil, S.
    Inst Space Syst, Deutsch Zentrum Luft & Raumfahrt, Fallturm 1, D-28359 Bremen, Germany..
    Tiede, C.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.;Univ Appl Sci Munich, Karlstr 6, D-80333 Munich, Germany..
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    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.;Univ Roma Tor Vergata, Dipartimento Fis, Via Ric Sci 1, I-00133 Rome, Italy..
    Tsalmantza, P.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Tur, D.
    Univ Catalunya, Consorci Serv, C Gran Capita 2-4 3rd Floor, Barcelona 08034, Spain..
    Vaccari, M.
    Univ Western Cape, Dept Phys & Astron, Robert Sobukwe Rd, ZA-7535 Cape Town, South Africa.;INAF Ist Radioastron, Via Gobetti 101, I-40129 Bologna, Italy..
    Vachier, F.
    UPMC Univ Paris 06, PSL Res Univ, IMCCE, Observ Paris,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Valles, P.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, E-08028 Barcelona, Spain..
    Van Hamme, W.
    Florida Int Univ, Dept Phys, 11200 SW 8th St, Miami, FL 33199 USA..
    Veltz, L.
    Univ Paris XI, CNRS, Inst Astrophys Spatiale, UMR 8617, Batiment 121, F-91405 Orsay, France.;Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany..
    Virtanen, J.
    Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland.;Finnish Geospatial Res Inst FGI, Geodeetinrinne 2, Masala 02430, Finland..
    Wallut, J. -M
    Wichmann, R.
    Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg, Germany..
    Wilkinson, M. I.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.;Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Ziaeepour, H.
    Univ Bourgogne Franche Comte, OSU THETA Franche Comte Bourgogne, CNRS, Inst UTINAM UMR6213, F-25000 Besancon, France..
    Zschocke, S.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Gaia Data Release 1 Summary of the astrometric, photometric, and survey properties2016In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 595, article id A2Article in journal (Refereed)
    Abstract [en]

    Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues - a realisation of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of similar to 3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr(-1) for the proper motions. A systematic component of similar to 0.3 mas should be added to the parallax uncertainties. For the subset of similar to 94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr(-1). For the secondary astrometric data set, the typical uncertainty of the positions is similar to 10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to similar to 0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data.

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    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy..
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    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy..
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    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
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    UNED, Dpto Inteligencia Artificial, C Juan Rosal 16, Madrid 28040, Spain..
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    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
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    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
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    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy..
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    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
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    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklosut 15-17, H-1121 Budapest, Hungary..
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    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
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    European Space Astron Ctr ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
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    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
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    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
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    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
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    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium.;FRS FNRS, Rue Egmont 5, B-1000 Brussels, Belgium..
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    INAF, Osservatorio Astrofis Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Italy..
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    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
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    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
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    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France..
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    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
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    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
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    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
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    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England..
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    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
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    Univ Copenhagen, Niels Bohr Inst, Juliane Manes Vej 30, DK-2100 Copenhagen, Denmark..
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    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
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    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
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    European Space Astron Ctr ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
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    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
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    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
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    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
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    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
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    Natl Observ Athens, Athens 15236, Greece..
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    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England..
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    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
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    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
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    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France.;UPMC, Univ Paris 06, Observ Paris, IMCCE,PSL Res Univ,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
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    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
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    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
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    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
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    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
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    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium..
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    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
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    INAF, Osservatorio Astrofis Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Italy..
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    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France..
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    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
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    Univ Pablo Olavide, Area Lenguajes & Sistemas Informat, Ctra Utrera,Km 1, Seville 141013, Spain..
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    FRS FNRS, Rue Egmont 5, B-1000 Brussels, Belgium.;Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
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    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
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    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
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    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England..
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    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain..
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    Univ Montpellier, Lab Univers & Particules Montpellier, Pl Eugene Bataillon CC72, F-34095 Montpellier 05, France..
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    Heidelberg Univ, Astron Rech Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
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    Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
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    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
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    Univ Catania, Dipartimento Fis & Astron, Sezione Astrofis, Via S Sofia 78, I-95123 Catania, Italy.;INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy..
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    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
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    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
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    Univ Helsinki, Dept Phys, POB 64, Helsinki 00014, Finland.;Finnish Geospatial Res Inst FGI, Geodeetinrinne 2, Masala 02430, Finland..
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    Isdefe, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
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    INAF, Osservatorio Astrofis Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Italy.;ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy..
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    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
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    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium..
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    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
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    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
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    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
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    UNED, Dpto Inteligencia Artificial, C Juan Rosal 16, Madrid 28040, Spain..
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    STFC, Rutherford Appleton Lab, Didcot, Oxon, England..
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    EURIX Srl, Via Carcano 26, I-10153 Turin, Italy..
    Altavilla, G.
    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
    Alvarez, M. A.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
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    Univ Vienna, Dept Astrophys, Turkenschanzstr 17, A-1180 Vienna, Austria..
    Andrei, A. H.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.;UPMC, CNRS, Univ Paris 06, SYRTE,Observ Paris,PSL Res Univ,Sorbonne Univ, 61 Ave Observ, F-75014 Paris, France.;ON MCTI BR, Rua Gal Jose Cristino 77, BR-20921400 Rio De Janeiro, RJ, Brazil.;OV UFRJ BR, Ladeira Pedro Antonio 43, BR-20080090 Rio De Janeiro, RJ, Brazil..
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    Serco Gestion Negocios, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.;Isdefe, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
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    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Antojal, T.
    European Space Res & Technol Ctr ESA ESTEC, Sci Support Off, Directorate Sci, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
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    Univ Porto, Dept Matemat Aplicada, Fac Ciencias, Rua Campo Alegre 687, P-4169007 Oporto, Portugal.;Univ Nova, Inst Astrofis & Ciencias Espaco, Fac Ciencias, P-PT1749016 Lisbon, Portugal..
    Arcay, B.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Bach, N.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Baker, S. G.
    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England..
    Balaguer-Nunez, L.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Barache, C.
    UPMC, CNRS, Univ Paris 06, SYRTE,Observ Paris,PSL Res Univ,Sorbonne Univ, 61 Ave Observ, F-75014 Paris, France..
    Barata, C.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Barbier, A.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Barblan, F.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Barrado y Navascues, D.
    Ctr Astrobiol, Dept Astrofis, CSIC INTA, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Barros, M.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Barstow, M. A.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Becciani, U.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy..
    Bellazzini, M.
    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
    Bello Garcia, A.
    Univ Oviedo, Campus Univ, Gijon 33203, Spain..
    Belokurov, V.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Bendjoya, P.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Berihuete, A.
    Univ Cadiz, Avd Univ, Cadiz 11002, Spain..
    Bianchi, L.
    EURIX Srl, Via Carcano 26, I-10153 Turin, Italy..
    Bienayme, O.
    Univ Strasbourg, CNRS, Observ Astronom Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France..
    Billebaud, F.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France..
    Blagorodnova, N.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Blanco-Cuaresma, S.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.;Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France..
    Boch, T.
    Univ Strasbourg, CNRS, Observ Astronom Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France..
    Bombrun, A.
    ESA ESAC, HE Space Operat BV, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Borrachero, R.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Bouquillon, S.
    UPMC, CNRS, Univ Paris 06, SYRTE,Observ Paris,PSL Res Univ,Sorbonne Univ, 61 Ave Observ, F-75014 Paris, France..
    Bourda, G.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France..
    Bragaglia, A.
    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
    Breddels, M. A.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands..
    Brouillet, N.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France..
    Bruesemeister, T.
    Heidelberg Univ, Astron Rech Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Bucciarelli, B.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Burgess, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Burgon, R.
    Open Univ, Dept Phys Sci, Ctr Elect Imaging, Walton Hall, Milton Keynes MK7 6AA, Bucks, England..
    Burlacu, A.
    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Busonero, D.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Buzzi, R.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Caffau, E.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Cambras, J.
    Univ Catalunya, Consorci Serv, C Gran Capita,2-4 3rd floor, Barcelona 08034, Spain..
    Campbell, H.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Cancelliere, R.
    Univ Turin, Dept Comp Sci, Corso Svizzera 185, I-10149 Turin, Italy..
    Cantat-Gaudin, T.
    INAF, Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy..
    Carlucci, T.
    UPMC, CNRS, Univ Paris 06, SYRTE,Observ Paris,PSL Res Univ,Sorbonne Univ, 61 Ave Observ, F-75014 Paris, France..
    Carrasco, J. M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Castellani, M.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Rome, Italy..
    Charlot, P.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France..
    Charnas, J.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Chiavassa, A.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Clotet, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Cocozza, G.
    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
    Collins, R. S.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Costigan, G.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Crifo, F.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Cross, N. J. G.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Crosta, M.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Crowley, C.
    ESA ESAC, HE Space Operat BV, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Dafonte, C.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Damerdji, Y.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium.;CRAAG, Route Observ BP 63 Bouzareah, Algiers 16340, Algeria..
    Dapergolas, A.
    Natl Observ Athens, Athens 15236, Greece..
    David, P.
    UPMC, Univ Paris 06, Observ Paris, IMCCE,PSL Res Univ,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    David, M.
    Univ Antwerp, Onderzoeksgroep Toegepaste Wiskunde, Middelheimlaan 1, B-2020 Antwerp, Belgium..
    De Cat, P.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    de Felice, F.
    Univ Padua, Dept Phys & Astron, Via Marzolo 8, I-35131 Padua, Italy..
    de Laverny, P.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    De Luise, F.
    INAF, Osservatorio Astron Teramo, Via Mentore Maggini, I-64100 Teramo, Italy..
    De March, R.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    de Souza, R.
    Univ Sao Paulo, Inst Astron, Geofis & Ciencias Atmosfer, Rua Matao 1226,Cidade Univ, BR-05508900 Sao Paulo, SP, Brazil..
    Debosscher, J.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium..
    del Pozo, E.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Delbo, M.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Delgado, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Delgado, H. E.
    UNED, Dpto Inteligencia Artificial, C Juan Rosal 16, Madrid 28040, Spain..
    Di Matteo, P.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Diakite, S.
    Univ Bourgogne Franche Comte, CNRS, Inst UTINAM UMR6213, OSU THETA Franche Comte Bourgogne, F-25000 Besancon, France..
    Distefano, E.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy..
    Dolding, C.
    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England..
    Dos Anjos, S.
    Univ Sao Paulo, Inst Astron, Geofis & Ciencias Atmosfer, Rua Matao 1226,Cidade Univ, BR-05508900 Sao Paulo, SP, Brazil..
    Drazinos, P.
    Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Duran, J.
    Isdefe, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Dzigan, Y.
    Tel Aviv Univ, Dept Geosci, IL-6997801 Tel Aviv, Israel.;Univ Amsterdam, Astron Inst Anton Pannekoek, POB 94249, NL-1090 GE Amsterdam, Netherlands..
    Edvardsson, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Enke, H.
    Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    Evans, N. W.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Bontemps, G. Eynard
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Fabre, C.
    Ctr Spatial Toulouse, ATOS, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Fabrizio, M.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.;INAF, Osservatorio Astron Teramo, Via Mentore Maggini, I-64100 Teramo, Italy..
    Falcao, A. J.
    UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal..
    Farras Casas, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Federici, L.
    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
    Fedorets, G.
    Univ Helsinki, Dept Phys, POB 64, Helsinki 00014, Finland..
    Fernandez-Hernandez, J.
    Serco Gestion Negocios, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.;UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal..
    Fernique, P.
    Univ Strasbourg, CNRS, Observ Astronom Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France..
    Fienga, A.
    Univ Nice Sophia Antipolis, CNRS, Lab Geoazur, UMR 7329,Observ Cote Azur, 250 Rue A Einstein, F-06560 Valbonne, France..
    Figueras, F.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Filippi, F.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Findeisen, K.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Fonti, A.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Fouesneau, M.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Fraile, E.
    ESA ESAC, RHEA, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Fraser, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Fuchs, J.
    Acad Sci Czech Republ, Astron Inst, Fricova 298, Ondiejov 25165, Czech Republic..
    Gai, M.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Galleti, S.
    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
    Galluccio, L.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Garabato, D.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Garcia-Sedano, F.
    UNED, Dpto Inteligencia Artificial, C Juan Rosal 16, Madrid 28040, Spain..
    Garralda, N.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Gavras, P.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;Natl Observ Athens, Athens 15236, Greece.;Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Gerssen, J.
    Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    Geyer, R.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Gilmore, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Girona, S.
    Barcelona Supercomp Ctr, Ctr Nacl Super Computac, C Jordi Girona 29,Ed Nexus 2, Barcelona 08034, Spain..
    Giuffrida, G.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy..
    Gomes, M.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Gonzalez-Marcos, A.
    Univ La Rioja, Dept Mech Engn, C San Jose Calasanz 31, La Rioja 26004, Spain..
    Gonzalez-Nunez, J.
    Serco Gestion Negocios, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.;Univ Vigo, ETSE Telecomunicac, Campus Lagoas Marcosende, Vigo 36310, Spain..
    Gonzalez-Vidal, J. J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Granvik, M.
    Univ Helsinki, Dept Phys, POB 64, Helsinki 00014, Finland..
    Guerrier, A.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Guillout, P.
    Univ Strasbourg, CNRS, Observ Astronom Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France..
    Guiraud, J.
    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Gurpide, A.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Gutierrez-Sanchez, R.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Guy, L. P.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Haigron, R.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Hatzidimitriou, D.
    Natl Observ Athens, Athens 15236, Greece.;Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Haywood, M.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Heiter, Ulrike
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Helmi, A.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands..
    Hobbs, D.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Hofmann, W.
    Heidelberg Univ, Astron Rech Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Holl, B.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Holland, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Hunt, J. A. S.
    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England..
    Hypki, A.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Icardi, V.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Irwin, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    de Fombelle, G. Jevardat
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Jofre, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England.;Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France..
    Jonker, P. G.
    Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands.;SRON Netherlands Inst Space Res, SRON, Sorbonnelaan 2, NL-3584 CA Utrecht, Netherlands..
    Jorissen, A.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium..
    Julbe, F.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Karampelas, A.
    Natl Observ Athens, Athens 15236, Greece.;Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Kochoska, A.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia..
    Kohley, R.
    European Space Astron Ctr ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Kolenberg, K.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.;Univ Antwerp, Phys Dept, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.;Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA..
    Kontizas, E.
    Natl Observ Athens, Athens 15236, Greece..
    Koposov, S. E.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Kordopatis, G.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France.;Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    Koubsky, P.
    Acad Sci Czech Republ, Astron Inst, Fricova 298, Ondiejov 25165, Czech Republic..
    Krone-Martins, A.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Kudryashova, M.
    UPMC, Univ Paris 06, Observ Paris, IMCCE,PSL Res Univ,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Bachchan, R. K.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Lacoste-Seris, F.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Lanza, A. F.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy..
    Lavigne, J. -B
    Le Poncin-Lafitte, C.
    UPMC, CNRS, Univ Paris 06, SYRTE,Observ Paris,PSL Res Univ,Sorbonne Univ, 61 Ave Observ, F-75014 Paris, France..
    Lebreton, Y.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;Univ Rennes 1, Inst Phys Rennes, F-35042 Rennes, France..
    Lebzelter, T.
    Univ Vienna, Dept Astrophys, Turkenschanzstr 17, A-1180 Vienna, Austria..
    Leccia, S.
    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy..
    Leclerc, N.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Lecoeur-Taibi, I.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Lemaitre, V.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Lenhardt, H.
    Heidelberg Univ, Astron Rech Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Leroux, F.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Liao, S.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.;Chinese Acad Sci, Shanghai Astron Observ, 80 Nandan Rd, Shanghai 200030, Peoples R China..
    Licata, E.
    EURIX Srl, Via Carcano 26, I-10153 Turin, Italy..
    Lindstrom, H. E. P.
    Univ Copenhagen, Niels Bohr Inst, Juliane Manes Vej 30, DK-2100 Copenhagen, Denmark.;CSC Danmark A S, Retortvej 8, DK-2500 Valby, Denmark..
    Lister, T. A.
    Las Cumbres Observ, Global Telescope Network Inc, 6740 Cortona Dr,Suite 102, Goleta, CA 93117 USA..
    Livanou, E.
    Univ Athens, Dept Astrophys Astron & Mech, Athens 15783, Greece..
    Lobel, A.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    Loeffler, W.
    Heidelberg Univ, Astron Rech Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Lopez, M.
    Ctr Astrobiol, Dept Astrofis, CSIC INTA, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Lorenz, D.
    Univ Vienna, Dept Astrophys, Turkenschanzstr 17, A-1180 Vienna, Austria..
    MacDonald, I.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Magalhaes Fernandes, T.
    Managau, S.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Mann, R. G.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Mantelet, G.
    Heidelberg Univ, Astron Rech Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Marchal, O.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Marchant, J. M.
    Liverpool John Moores Univ, Astrophys Res Inst, Liverpool L3 5RF, Merseyside, England..
    Marinoni, S.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.;INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Rome, Italy..
    Marrese, P. M.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.;INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Rome, Italy..
    Marschalko, G.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklosut 15-17, H-1121 Budapest, Hungary.;Univ Szeged, Baja Observ, Szegedi 3-70, H-6500 Baja, Hungary..
    Marsha, D. J.
    Univ Paris Diderot, CEA Saclay, Serv Astrophys, Lab AIM,IRFU,CEA DSM,CNRS,Bat 709, F-91191 Gif Sur Yvette, France..
    Martin-Fleitas, J. M.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Martino, M.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Mary, N.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Matijevic, G.
    Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    McMillan, P. J.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Messina, S.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy..
    Michalik, D.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Millar, N. R.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Miranda, B. M. H.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Molina, D.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Molinaro, M.
    INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34143 Trieste, Italy..
    Molnar, L.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklosut 15-17, H-1121 Budapest, Hungary..
    Monicz, M.
    Univ Paris 11, Univ Paris Saclay, Lab Accelerateur Lineaire, CNRS IN2P3, F-91898 Orsay, France..
    Montegriffo, P.
    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
    Mor, R.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Mora, A.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Morbidelli, R.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Morel, T.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Morgenthaler, S.
    Ecole Polytech Fed Lausanne, SB MATHAA STAP, MA B1 473 Batiment MA,Stn 8, CH-1015 Lausanne, Switzerland..
    Morris, D.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Mulone, A. F.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Narbonne, J.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Nelemans, G.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.;Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands..
    Nicastro, L.
    INAF, Ist Astrofis Spaziale & Fis Cosm Bologna, Via Piero Gobetti 101, I-40129 Bologna, Italy..
    Noval, L.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Ordenovic, C.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Ordieres-Mere, J.
    Tech Univ Madrid, Jose Gutierrez Abascal 2, Madrid 28006, Spain..
    Osborne, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Pagani, C.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Pagano, I.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy..
    Pailler, F.
    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Palacin, H.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Palaversa, L.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Parsons, P.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Pecoraro, M.
    EURIX Srl, Via Carcano 26, I-10153 Turin, Italy..
    Pedrosa, R.
    Ctr Spatial Toulouse, EQUERT Int, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Pentikainen, H.
    Univ Helsinki, Dept Phys, POB 64, Helsinki 00014, Finland..
    Pichon, B.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Piersimoni, A. M.
    INAF, Osservatorio Astron Teramo, Via Mentore Maggini, I-64100 Teramo, Italy..
    Pineau, F. -X
    Plachy, E.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklosut 15-17, H-1121 Budapest, Hungary..
    Plum, G.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Poujoulet, E.
    Ctr Spatial Toulouse, AKKA, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Prsa, A.
    Villanova Univ, Dept Astrophys & Planetary Sci, 800 E Lancaster Ave, Villanova, PA 19085 USA..
    Pulone, L.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Rome, Italy..
    Ragaini, S.
    INAF, Osservatorio Astron Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy..
    Rago, S.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Rambaux, N.
    UPMC, Univ Paris 06, Observ Paris, IMCCE,PSL Res Univ,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Ramos-Lerate, M.
    Vitrociset Belgium, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Ranalli, P.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden..
    Rauw, G.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Read, A.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Regibo, S.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium..
    Reyle, C.
    Univ Bourgogne Franche Comte, CNRS, Inst UTINAM UMR6213, OSU THETA Franche Comte Bourgogne, F-25000 Besancon, France..
    Ribeiro, R. A.
    UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal..
    Riva, A.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Rixon, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Roelens, M.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Romero-Gomez, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Rowell, N.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Royer, F.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Ruiz-Dern, L.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Sadowski, G.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium..
    Selles, T. Sagrista
    Heidelberg Univ, Astron Rech Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Sahlmann, J.
    European Space Astron Ctr ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Salgado, J.
    Isdefe, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Salguero, E.
    Isdefe, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Sarasso, M.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Savietto, H.
    Fork Res, Rua Cruzado Osberno,Lt 1,9 Esq, Lisbon, Portugal..
    Schultheis, M.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Sciacca, E.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy..
    Segol, M.
    APAVE SUDEUROPE SAS, Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Segovia, J. C.
    Serco Gestion Negocios, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Segransan, D.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Shih, I-C
    Smareglia, R.
    INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34143 Trieste, Italy..
    Smart, R. L.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Solano, E.
    Ctr Astrobiol, Dept Astrofis, CSIC INTA, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.;Spanish Virtual Observ, San Cristobal la Laguna, Spain..
    Solitro, F.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Sordo, R.
    INAF, Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy..
    Soria Nieto, S.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Souchay, J.
    UPMC, CNRS, Univ Paris 06, SYRTE,Observ Paris,PSL Res Univ,Sorbonne Univ, 61 Ave Observ, F-75014 Paris, France..
    Spagna, A.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Spoto, F.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Stampa, U.
    Heidelberg Univ, Astron Rech Inst, Zentrum Astron, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Steele, I. A.
    Liverpool John Moores Univ, Astrophys Res Inst, Liverpool L3 5RF, Merseyside, England..
    Steidelmueller, H.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Stephenson, C. A.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Stoev, H.
    INAF, Fdn Galileo Galilei, Rambla Jose Ana Fernandez Perez 7, Brefia Baja 38712, Santa Cruz Tene, Spain..
    Suess, F. F.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Suveges, M.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Surdej, J.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Szegedi-Elek, E.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklosut 15-17, H-1121 Budapest, Hungary..
    Tapiador, D.
    ESA ESAC, INSA, Camino Bajo Castillo S-N, Madrid 28692, Spain.;Univ Complutense Madrid, Dpto Arquitectura Comp & Automat, Fac Informat, C-Prof Jose Garcia Santesmases S-N, Madrid 28040, Spain..
    Taris, F.
    Tauran, G.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Taylor, M. B.
    Univ Bristol, HH Wills Phys Lab, Tyndall Ave, Bristol BS8 1TL, Avon, England..
    Teixeira, R.
    Univ Sao Paulo, Inst Astron, Geofis & Ciencias Atmosfer, Rua Matao 1226,Cidade Univ, BR-05508900 Sao Paulo, SP, Brazil..
    Terrett, D.
    STFC, Rutherford Appleton Lab, Didcot, Oxon, England..
    Tingley, B.
    Aarhus Univ, Dept Phys & Astron, Stellar Astrophys Ctr, 120 Ny Munkegade,Bldg 1520, DK-8000 Aarhus, Denmark..
    Trager, S. C.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands..
    Turon, C.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Ulla, A.
    Univ Vigo, Appl Phys Dept, Vigo 36310, Spain..
    Utrilla, E.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Valentini, G.
    INAF, Osservatorio Astron Teramo, Via Mentore Maggini, I-64100 Teramo, Italy..
    van Elteren, A.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Van Hemelryck, E.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    van Leeuwen, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Varadi, M.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.;Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklosut 15-17, H-1121 Budapest, Hungary..
    Vecchiato, A.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Veljanoski, J.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands..
    Via, T.
    Univ Catalunya, Consorci Serv, C Gran Capita,2-4 3rd floor, Barcelona 08034, Spain..
    Vicente, D.
    Barcelona Supercomp Ctr, Ctr Nacl Super Computac, C Jordi Girona 29,Ed Nexus 2, Barcelona 08034, Spain..
    Vogt, S.
    HE Space Operat BV, ESA ESTEC, Keplerlaan 1, NL-2201AZ Noordwijk, Netherlands..
    Voss, H.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Votruba, V.
    Acad Sci Czech Republ, Astron Inst, Fricova 298, Ondiejov 25165, Czech Republic..
    Voutsinas, S.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Walmsley, G.
    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Weiler, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Weingrill, K.
    Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    Wevers, T.
    Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands..
    Wyrzykowski, L.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England.;Univ Warsaw Observ, Al Ujazdowskie 4, PL-00478 Warsaw, Poland..
    Yoldas, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Zerjal, M.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia..
    Zucker, S.
    Tel Aviv Univ, Dept Geosci, IL-6997801 Tel Aviv, Israel..
    Zurbach, C.
    Univ Montpellier, Lab Univers & Particules Montpellier, Pl Eugene Bataillon CC72, F-34095 Montpellier 05, France..
    Zwitter, T.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia..
    Alecu, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Allen, M.
    European Space Res & Technol Ctr ESA ESTEC, Sci Support Off, Directorate Sci, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Allende Prieto, C.
    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.;Inst Astrofis Canarias, San Cristobal la Laguna 38205, Tenerife, Spain.;Univ La Laguna, Dept Astrofis, San Cristobal la Laguna 38206, Tenerife, Spain..
    Amorim, A.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Anglada-Escude, G.
    Arsenijevic, V.
    Univ Lisbon, CENTRA, FCUL, Edif C8, P-1749016 Lisbon, Portugal..
    Azaz, S.
    European Space Res & Technol Ctr ESA ESTEC, Sci Support Off, Directorate Sci, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Balm, P.
    Telespazio Vega UK Ltd, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Beck, M.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Bernsteint, H. -H
    Bigot, L.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Bijaoui, A.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Blasco, C.
    ESA, ESTEC, RHEA, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Bonfigli, M.
    INAF, Osservatorio Astron Teramo, Via Mentore Maggini, I-64100 Teramo, Italy..
    Bono, G.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Rome, Italy..
    Boudreault, S.
    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.;Max Planck Inst Solar Syst Res, Justus Von Liebig Weg 3, D-37077 Gottingen, Germany..
    Bressan, A.
    SISSA, Via Bonomea 265, I-34136 Trieste, Italy..
    Brown, S.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Brunet, P. -M
    Bunclark, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Buonanno, R.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Rome, Italy..
    Butkevich, A. G.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Carret, C.
    Ctr Spatial Toulouse, EQUERT Int, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Carrion, C.
    UNED, Dpto Inteligencia Artificial, C Juan Rosal 16, Madrid 28040, Spain..
    Chemin, L.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N, F-33615 Pessac, France.;Inst Nacl Pesquisas Espaciais, Minist Ciencia Tecnol, Ave Astronautas 1758, BR-12227010 Sao Jose Dos Campos, SP, Brazil..
    Chereau, F.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Corcione, L.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Darmigny, E.
    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    de Boer, K. S.
    Univ Bonn, Argelander Inst Astron, Hugel 71, D-53121 Bonn, Germany..
    de Teodoro, P.
    Serco Gestion Negocios, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    de Zeeuw, P. T.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands.;ESO, Karl Schwarzschild Str 2, D-85748 Garching, Germany..
    Delle Luche, C.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Domingues, C. D.
    Univ Lisbon, Fac Sci, Lab Opt Lasers & Syst, Estr Paco Lumiar 22, P-1649038 Lisbon, Portugal..
    Dubath, P.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Fodor, F.
    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Frezouls, B.
    Ctr Spatial Toulouse, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Fries, A.
    Fustes, D.
    Univ A Coruna, Fac Informat, Campus Elvina S-N, La Coruna 15071, Spain..
    Fyfe, D.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Gallardo, E.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Gallegos, J.
    Serco Gestion Negocios, ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Gardiol, D.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Gebran, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain.;Notre Dame Univ, Dept Phys & Astron, POB 72, Zouk Mikael, Lebanon..
    Gomboc, A.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia.;Univ Nova Gorica, Vipayska 13, Nova Gorica 5000, Slovenia..
    Gomez, A.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Grux, E.
    Univ Bourgogne Franche Comte, CNRS, Inst UTINAM UMR6213, OSU THETA Franche Comte Bourgogne, F-25000 Besancon, France..
    Gueguen, A.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;Max Planck Inst Extraterr Phys, OPINAS, Giessenbachstr, D-85741 Garching, Germany..
    Heyrovsky, A.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Hoar, J.
    European Space Astron Ctr ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Iannicola, G.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Rome, Italy..
    Parache, Y. Isasi
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Janotto, A. -M
    Joliet, E.
    ESA ESAC, HE Space Operat BV, Camino Bajo Castillo S-N, Madrid 28692, Spain.;CALTECH, NASA IPAC Infrared Sci Arch, Mail Code 100-22,770 South Wilson Ave, Pasadena, CA 91125 USA..
    Jonckheere, A.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium..
    Keil, R.
    Univ Bremen, Ctr Appl Space Technol & Micrograv ZARM, Am Fallturm 1, D-28359 Bremen, Germany.;ESA, ESOC, RHEA Syst, Robert Bosch Str 5, D-64293 Darmstadt, Germany..
    Kim, D. -W
    Klagyivik, P.
    Hungarian Acad Sci, Res Ctr Astron & Earth Sci, Konkoly Observ, Konkoly Thege Miklosut 15-17, H-1121 Budapest, Hungary..
    Klar, J.
    Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    Knude, J.
    Univ Copenhagen, Niels Bohr Inst, Juliane Manes Vej 30, DK-2100 Copenhagen, Denmark..
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Kolka, I.
    Tartu Observ, EE-61602 Toravere, Estonia..
    Kos, J.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia.;Univ Sydney, Sch Phys A28, Sydney Inst Astron, Sydney, NSW 2006, Australia..
    Kutka, A.
    Acad Sci Czech Republ, Astron Inst, Fricova 298, Ondiejov 25165, Czech Republic.;Slovak Org Space Activ, Zamocka 18, Bratislava 85101, Slovakia..
    Lainey, V.
    UPMC, Univ Paris 06, Observ Paris, IMCCE,PSL Res Univ,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    LeBouquin, D.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Liu, C.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.;Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China..
    Loreggia, D.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Makarov, V. V.
    US Naval Observ, Astrometry Dept, 3450 Massachusetts Ave, Washington, DC 20392 USA..
    Marseille, M. G.
    Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Martayan, C.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.;ESO, Alonso Cordova 3107,Casilla 19001, Santiago, Chile..
    Martinez-Rubi, O.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Massart, B.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France.;Ctr Spatial Toulouse, Thales Serv, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.;Airbus Def & Space SAS, 31 Rue Cosmonautes, F-31402 Toulouse 4, France..
    Meynadier, F.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France.;UPMC, CNRS, Univ Paris 06, SYRTE,Observ Paris,PSL Res Univ,Sorbonne Univ, 61 Ave Observ, F-75014 Paris, France..
    Mignot, S.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Munari, U.
    INAF, Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy..
    Nguyen, A. -T
    Nordlander, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    O'Flaherty, K. S.
    ESA ESTEC, EJR Quartz BV, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Ocvirk, P.
    Univ Strasbourg, CNRS, Observ Astronom Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France.;Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    Olias Sanz, A.
    ESA ESAC, Server Labs, Camino Bajo Castillo S-N, Madrid, Spain..
    Ortiz, P.
    Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Osorio, J.
    Univ Porto, Dept Matemat Aplicada, Fac Ciencias, Rua Campo Alegre 687, P-4169007 Oporto, Portugal..
    Oszkiewicz, D.
    Univ Helsinki, Dept Phys, POB 64, Helsinki 00014, Finland.;Adam Mickiewicz Univ, Fac Phys, Astron Observ Inst, Ul Sloneczna 36, PL-60286 Poznan, Poland..
    Ouzounis, A.
    Univ Edinburgh, Inst Astron, Royal Observ, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Park, P.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Pasquato, E.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium..
    Peltzer, C.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England..
    Peralta, J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Peturaud, F.
    Univ Paris Diderot, Observ Paris, CNRS, GEPI,PSL Res Univ,Sorbonne Paris Cite, 5 Pl Jules Janssen, F-92190 Meudon, France..
    Pieniluoma, T.
    Univ Helsinki, Dept Phys, POB 64, Helsinki 00014, Finland..
    Pigozzi, E.
    ALTEC Spa, Corso Marche 79, I-10146 Turin, Italy..
    Poels, J.
    Univ Liege, Inst Astrophys & Geophys, 19c,Allee 6 Aout, B-4000 Liege, Belgium..
    Prat, G.
    CS Syst Informat CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France..
    Prod'homme, T.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands.;European Space Res & Technol Ctr ESA ESTEC, Directorate Sci, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands..
    Raison, F.
    Max Planck Inst Extraterr Phys, OPINAS, Giessenbachstr, D-85741 Garching, Germany.;ESA ESAC, Praesepe BV, Camino Bajo Castillo S-N, Madrid 28692, Spain..
    Rebordao, J. M.
    Univ Lisbon, Fac Sci, Lab Opt Lasers & Syst, Estr Paco Lumiar 22, P-1649038 Lisbon, Portugal..
    Risquez, D.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands..
    Rocca-Volmerange, B.
    Sorbonne Univ UPMC, CNRS, UMR7095, Inst Astrophys Paris, F-75014 Paris, France..
    Rosen, S.
    Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.;Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Ruiz-Fuertes, M. I.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland..
    Russo, F.
    INAF, Osservatorio Astron Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy..
    Serraller Vizcaino, I.
    ESA ESAC, GMV, Camino bajo Castillo S-N, Madrid 28692, Spain..
    Short, A.
    Siebert, A.
    Univ Strasbourg, CNRS, Observ Astronom Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France.;Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    Silva, H.
    UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal..
    Sinachopoulos, D.
    Natl Observ Athens, Athens 15236, Greece..
    Slezak, E.
    Univ Nice Sophia Antipolis, Lab Lagrange, Observ Cote Azur, CNRS, CS 34229, F-06304 Nice, France..
    Soffel, M.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Sosnowska, D.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland..
    Straizys, V.
    Vilnius Univ, Inst Theoret Phys & Astron, Sauletekio 3, LT-10222 Vilnius, Lithuania..
    ter Linden, M.
    ESA ESAC, HE Space Operat BV, Camino Bajo Castillo S-N, Madrid 28692, Spain.;S&T Corp, POB 608, NL-2600 AP Delft, Netherlands..
    Terrell, D.
    Southwest Res Inst SwRI, Dept Space Studies, 1050 Walnut St,Suite 300, Boulder, CO 80302 USA..
    Theil, S.
    Deutsch Zentrum Luft & Raumfahrt, Inst Space Syst, Fallturm 1, D-28359 Bremen, Germany..
    Tiede, C.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.;Univ Appl Sci Munich, Karlstr 6, D-80333 Munich, Germany..
    Troisi, L.
    ASI Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.;Univ Roma Tor Vergata, Dipartimento Fis, Via Ric Sci 1, I-00133 Rome, Italy..
    Tsalmantza, P.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Tur, D.
    Univ Catalunya, Consorci Serv, C Gran Capita,2-4 3rd floor, Barcelona 08034, Spain..
    Vaccari, M.
    Univ Western Cape, Dept Phys & Astron, Robert Sobukwe Rd, ZA-7535 Cape Town, South Africa.;INAF, Ist Radioastron, Via Piero Gobetti 101, I-40129 Bologna, Italy..
    Vachier, F.
    UPMC, Univ Paris 06, Observ Paris, IMCCE,PSL Res Univ,CNRS,Sorbonne Univ,Univ Lille, 77 Av Denfert Rochereau, F-75014 Paris, France..
    Valles, P.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti Franques 1, Barcelona 08028, Spain..
    Van Hamme, W.
    Florida Int Univ, Dept Phys, 11200 SW 8th St, Miami, FL 33199 USA..
    Veltz, L.
    Univ Paris XI, CNRS, Inst Astrophys Spatiale, UMR 8617, Batiment 121, F-91405 Orsay, France.;Leibniz Inst Astrophys Potsdam AIP, An Der Stern warte 16, D-14482 Potsdam, Germany..
    Virtanen, J.
    Univ Helsinki, Dept Phys, POB 64, Helsinki 00014, Finland.;Finnish Geospatial Res Inst FGI, Geodeetinrinne 2, Masala 02430, Finland..
    Wallut, J. -M
    Wichmann, R.
    Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg, Germany..
    Wilkinson, M. I.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England.;Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England..
    Ziaeepour, H.
    Univ Bourgogne Franche Comte, CNRS, Inst UTINAM UMR6213, OSU THETA Franche Comte Bourgogne, F-25000 Besancon, France..
    Zschocke, S.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany..
    Testing parallaxes with local Cepheids and RR Lyrae stars2017In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 605, article id A79Article in journal (Refereed)
    Abstract [en]

    Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the HIPPARCOS and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (MV-[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS.

    Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with sigma(omega)/omega < 0 : 5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with sigma(omega)/omega 0 : 5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with sigma(omega)/omega < 0 : 5). The new relations were computed using multi- band (V; I; J; K-s) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL; PW; PLZ, and MV [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods.

    Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the HIPPARCOS measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive.

    Conclusions. TGAS parallaxes bring a significant added value to the previous HIPPARCOS estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018.

  • 12.
    Cole, E. M.
    et al.
    Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland..
    Hackman, T.
    Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland.;Univ Turku, Finnish Ctr Astron ESO, Piikkio 21500, Finland..
    Kapyka, M. J.
    Aalto Univ, Dept Comp Sci, ReSoLVE Ctr Excellence, Espoo 00076, Finland..
    Ilyin, I.
    Leibniz Inst Astrophys Potsdam, D-14882 Potsdam, Germany..
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Doppler imaging of LQ Hydrae for 1998-20022015In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 581, article id A69Article in journal (Refereed)
    Abstract [en]

    Aims. We study the spot distribution on the surface of LQ Hya during the observing seasons October 1998-November 2002. We look for persistent active longitudes, trends in the level of spot activity and compare to photometric data. Methods. We apply the Doppler imaging technique on photospheric spectral lines using an inversion code to retrieve images of the surface temperature. Results. We present new temperature maps using multiple spectral lines for a total of 7 seasons. Conclusions. We find no evidence for active longitudes persisting over multiple observing seasons. The spot activity appears to be concentrated to two latitude regions. Using the currently accepted rotation period, we find spot structures to show a trend in the phase-time plot, indicative of a need for a longer period. We conclude that the long-term activity of LQ Hya is more chaotic than that of some magnetically active binary stars analyzed with similar methods, but still with clear indications of an activity cycle from the photometry.

  • 13.
    Farihi, J.
    et al.
    UCL, Dept Phys & Astron, London WC1E 6BT, England..
    Fossati, L.
    Austrian Acad Sci, Space Res Inst, A-8042 Graz, Austria..
    Wheatley, P. J.
    Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England..
    Metzger, B. D.
    Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA..
    Mauerhan, J.
    Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA..
    Bachman, S.
    Indiana Univ Penn, Dept Phys, Indiana, PA 15705 USA.;Wesleyan Univ, Astron Dept, Middletown, CT 06459 USA.;Wesleyan Univ, Van Vleck Observ, Middletown, CT 06459 USA..
    Gänsicke, B. T.
    Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England..
    Redfield, S.
    Wesleyan Univ, Astron Dept, Middletown, CT 06459 USA.;Wesleyan Univ, Van Vleck Observ, Middletown, CT 06459 USA..
    Cauley, P. W.
    Wesleyan Univ, Astron Dept, Middletown, CT 06459 USA.;Wesleyan Univ, Van Vleck Observ, Middletown, CT 06459 USA..
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Achilleos, N.
    UCL, Dept Phys & Astron, London WC1E 6BT, England..
    Stone, N.
    Columbia Univ, Dept Astron, New York, NY 10027 USA..
    Magnetism, X-rays and accretion rates in WD 1145+017 and other polluted white dwarf systems2018In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 474, no 1, p. 947-960Article in journal (Refereed)
    Abstract [en]

    This paper reports circular spectropolarimetry and X-ray observations of several polluted white dwarfs including WD 1145+017, with the aim to constrain the behaviour of disc material and instantaneous accretion rates in these evolved planetary systems. Two stars with previously observed Zeeman splitting, WD 0322-019 and WD 2105-820, are detected above 5 sigma and < B-z > > 1 kG, while WD 1145+017, WD 1929+011, and WD 2326+049 yield (null) detections below this minimum level of confidence. For these latter three stars, high-resolution spectra and atmospheric modelling are used to obtain limits on magnetic field strengths via the absence of Zeeman splitting, finding B-* < 20 kG based on data with resolving power R approximate to 40 000. An analytical framework is presented for bulk Earth composition material falling on to the magnetic polar regions of white dwarfs, where X-rays and cyclotron radiation may contribute to accretion luminosity. This analysis is applied to X-ray data for WD 1145+017, WD 1729+371, and WD 2326+049, and the upper bound count rates are modelled with spectra for a range of plasma kT = 1-10 keV in both the magnetic and non-magnetic accretion regimes. The results for all three stars are consistent with a typical dusty white dwarf in a steady state at 108-109 g s(-1). In particular, the non-magnetic limits for WD 1145+017 are found to be well below previous estimates of up to 10(12) g s(-1), and likely below 1010 g s(-1), thus suggesting the star-disc system may be average in its evolutionary state, and only special in viewing geometry.

  • 14. Folsom, C. P.
    et al.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Wade, G. A.
    Silvester, J.
    Bagnulo, S.
    Magnetic field, chemical composition and line profile variability of the peculiar eclipsing binary star AR Aur2010In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 407, no 4, p. 2383-2392Article in journal (Refereed)
    Abstract [en]

    AR Aur is the only eclipsing binary known to contain a HgMn star, making it an ideal case for a detailed study of the HgMn phenomenon. HgMn stars are a poorly understood class of chemically peculiar stars, which have traditionally been thought not to possess significant magnetic fields. However, the recent discovery of line profile variability in some HgMn stars, apparently attributable to surface abundance patches, has brought this belief into question. In this paper we investigate the chemical abundances, line profile variability, and magnetic field of the primary and secondary of the AR Aur system, using a series of high-resolution spectropolarimetric observations. We find the primary is indeed a HgMn star, and present the most precise abundances yet determined for this star. We find the secondary is a weak Am star, and is possibly still on the pre-main sequence. Line profile variability was observed in a range of lines in the primary, and is attributed to inhomogeneous surface distributions of some elements. No magnetic field was detected in any observation of either stars, with an upper limit on the longitudinal magnetic field in both stars of 100 G. Modelling of the phase-resolve longitudinal field measurements leads to a 3 Sigma upper limit on any dipole surface magnetic field of about 400 G.

  • 15. Folsom, C. P.
    et al.
    Likuski, K.
    Wade, G. A.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Alecian, E.
    Shulyak, D.
    Orbital parameters, chemical composition and magnetic field of the Ap binary HD 980882013In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 431, no 2, p. 1513-1527Article in journal (Refereed)
    Abstract [en]

    HD 98088 is a synchronized, double-lined spectroscopic binary system with a magnetic Ap primary component and an Am secondary component. We study this rare system using high-resolution Multi-Site Continuous Spectroscopy spectropolarimetric data, to gain insight into the effect of binarity on the origin of stellar magnetism and the formation of chemical peculiarities in A-type stars. Using a new collection of 29 high-resolution Stokes VQU spectra we re-derive the orbital and stellar physical parameters and conduct the first disentangling of spectroscopic observations of the system to conduct spectral analysis of the individual stellar components. From this analysis we determine the projected rotational velocities of the stars and conduct a detailed chemical abundance analysis of each component using both the SYNTH3 and ZEEMAN spectrum synthesis codes. The surface abundances of the primary component are typical of a cool Ap star, while those of the secondary component are typical of an Am star. We present the first magnetic analysis of both components using modern data. Using least-squares deconvolution, we extract the longitudinal magnetic field strength of the primary component, which is observed to vary between +1170 and -920 G with a period consistent with the orbital period. There is no field detected in the secondary component. The magnetic field in the primary is predominantly dipolar, with the positive pole oriented approximately towards the secondary.

  • 16. Fossati, L.
    et al.
    Ayres, T. R.
    Haswell, C. A.
    Bohlender, D.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Floeer, L.
    Absorbing gas around the WASP-12 planetary system2013In: ASTROPHYSICAL JOURNAL LETTERS, ISSN 2041-8205, Vol. 766, no 2, p. L20-Article in journal (Refereed)
    Abstract [en]

    Near-UV observations of the planet host star WASP-12 uncovered the apparent absence of the normally conspicuous core emission of the Mg II h and k resonance lines. This anomaly could be due either to (1) a lack of stellar activity, which would be unprecedented for a solar-like star of the imputed age of WASP-12 or (2) extrinsic absorption, from the intervening interstellar medium (ISM) or from material within the WASP-12 system itself, presumably ablated from the extreme hot Jupiter WASP-12 b. HIRES archival spectra of the Ca II H and K lines of WASP-12 show broad depressions in the line cores, deeper than those of other inactive and similarly distant stars and similar to WASP-12's Mg II h and k line profiles. We took high-resolution ESPaDOnS and FIES spectra of three early-type stars within 20' of WASP-12 and at similar distances, which show the ISM column is insufficient to produce the broad Ca II depression observed in WASP-12. The EBHIS H I column density map supports and strengthens this conclusion. Extrinsic absorption by material local to the WASP-12 system is therefore the most likely cause of the line core anomalies. Gas escaping from the heavily irradiated planet could form a stable and thick circumstellar disk/cloud. The anomalously low stellar activity index (logR'(HK)) of WASP-12 is evidently a direct consequence of the extra core absorption, so similar HK index deficiencies might signal the presence of translucent circumstellar gas around other stars hosting evaporating planets.

  • 17. Fossati, L.
    et al.
    Ayres, T. R.
    Haswell, C. A.
    Jenkins, J. S.
    Bisikalo, D.
    Bohlender, D.
    Floer, L.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Searching for a gas cloud surrounding the WASP-18 planetary system2014In: Astrophysics and Space Science, ISSN 0004-640X, E-ISSN 1572-946X, Vol. 354, no 1, p. 21-28Article in journal (Refereed)
    Abstract [en]

    Near-UV (NUV) Hubble Space Telescope (HST) observations of the extreme hot-Jupiter WASP-12b revealed the presence of diffuse exospheric gas extending beyond the planet's Roche lobe. Furthermore the NUV observations showed a complete lack of the normally bright core emission of the Mg ii h&k resonance lines, in agreement with the measured anomalously low stellar activity index (logR' (HK) ). Comparisons with other distant and inactive stars, and the analysis of radio and optical measurements of the intervening interstellar medium (ISM), led us to the conclusion that the system is surrounded by a circumstellar gas cloud, likely formed of material lost by the planet. Similar anomalous logR' (HK) index deficiencies might therefore signal the presence of translucent circumstellar gas around other stars hosting evaporating planets; we identified five such systems and WASP-18 is one of them. Both radio and optical observations of the region surrounding WASP-18 point towards a negligible ISM absorption along the WASP-18 line of sight. Excluding the unlikely possibility of an intrinsic anomalously low stellar activity, we conclude that the system is probably surrounded by a circumstellar gas cloud, presumably formed of material lost by the planet. Nevertheless only a far-UV spectrum of the star would provide a definite answer. Theoretical modelling suggests WASP-18b undergoes negligible mass loss, in contrast to the probable presence of a circumstellar gas cloud formed of material lost by the planet. The solution might be the presence either of an extra energy source driving mass loss (e.g., the reconnection of the stellar and planetary magnetic fields inside the planet atmosphere) or of an evaporating third body (e.g., moon).

  • 18. Fossati, L.
    et al.
    Bagnulo, S.
    Elmasli, A.
    Haswell, C. A.
    Holmes, S.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Shkolnik, E. L.
    Shulyak, D. V.
    Bohlender, D.
    Albayrak, B.
    Froning, C.
    Hebb, L.
    A detailed spectropolarimetric analysis of the planet-hosting star WASP-122010In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 720, no 1, p. 872-886Article in journal (Refereed)
    Abstract [en]

    The knowledge of accurate stellar parameters is paramount in several fields of stellar astrophysics, particularly in the study of extrasolar planets, where often the star is the only visible component and therefore used to infer the planet's fundamental parameters. Another important aspect of the analysis of planetary systems is the stellar activity and the possible star planet interaction. Here, we present a self-consistent abundance analysis of the planet-hosting star WASP-12 and a high-precision search for a structured stellar magnetic field on the basis of spectropolarimetric observations obtained with the ESPaDOnS spectropolarimeter. Our results show that the star does not have a structured magnetic field, and that the obtained fundamental parameters are in good agreement with what was previously published. In addition, we derive improved constraints on the stellar age (1.0-2.65 Gyr), mass (1.23-1.49 M/M-circle dot), and distance (295-465 pc). WASP-12 is an ideal object in which to look for pollution signatures in the stellar atmosphere. We analyze the WASP-12 abundances as a function of the condensation temperature and compare them with those published by several other authors on planet-hosting and non-planet-hosting stars. We find hints of atmospheric pollution in WASP-12's photosphere but are unable to reach firm conclusions with our present data. We conclude that a differential analysis based on WASP-12 twins will probably clarify whether an atmospheric pollution is present as well as the nature of this pollution and its implications in planet formation and evolution. We also attempt the direct detection of the circumstellar disk through infrared excess, but without success.

  • 19.
    Fossati, L.
    et al.
    Univ Bonn, Argelander Inst Astron, Bonn, Germany..
    Bagnulo, S.
    Armagh Observ, Armagh BT61 9DG, North Ireland..
    Landstreet, J. D.
    Univ Western Ontario, London, ON, Canada..
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy. Uppsala Univ, Uppsala, Sweden..
    Comprehensive and Critical Reanalysis of FORS Spectropolarimetric Observations: the Case of HD922072015In: Physics and Evolution of Magnetic and Related Stars, 2015, Vol. 494, p. 63-75Conference paper (Refereed)
    Abstract [en]

    Stellar spectropolarimetry has become extremely popular during the past decade, and has led to major advances in our understanding of stellar magnetic fields and their impact on stellar structure and evolution. Many important discoveries have been made thanks to the observations performed with the FORS low-resolution spectropolarimeters of the ESO Very Large Telescope. We first review and summarize the major results of a homogeneous re-reduction and analysis of all single-slit FORS1 spectropolarimetric observations. This work revealed a non-negligible dependence of the results upon the adopted reduction and analysis procedure, as well as the presence of instabilities, revealing that photon noise is not the only source of uncertainty. As a consequence of our new analysis and assessment of uncertainties, we are not able to confirm a large number of magnetic field detections presented in the past for a variety of stars. We further summarize the results of FORS2 spectropolarimetric observations of the A0 supergiant HD92207, which allowed us to explore further the nature of the instabilities, roughly constraining their maximum impact on the derived Stokes profiles and magnetic field values. We finally present new results obtained with a further independent pipeline on the FORS2 data of HD92207, confirming our previous analysis, and discuss simple quality-check controls, which can be performed on the data in order to distinguish between the genuine and spurious signals. All together, our results reveal that the FORS spectropolarimeters are indeed reliable instruments when their capabilities are not pushed beyond the limits of the mounted Cassegrain low-resolution spectrograph.

  • 20. Fossati, L.
    et al.
    Bagnulo, S.
    Monier, R.
    Khan, S.A.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Astronomy and Space Physics, Observational Astronomy.
    Landstreet, J.
    Wade, G.
    Weiss, W.
    Late stages of the evolution of A-type stars on the main sequence: Comparison between observed chemical abundances and diffusion models for 8 Am stars of the Praesepe cluster2007In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 476, no 2, p. 911-925Article in journal (Refereed)
    Abstract [en]

    Aims. We aim to provide observational constraints on diffusion models that predict peculiar chemical abundances in the atmospheres of Am stars. We also intend to check if chemical peculiarities and slow rotation can be explained by the presence of a weak magnetic field. Methods. We have obtained high resolution, high signal-to-noise ratio spectra of eight previously-classified Am stars, two normal A-type stars and one Blue Straggler, considered to be members of the Praesepe cluster. For all of these stars we have determined fundamental parameters and photospheric abundances for a large number of chemical elements, with a higher precision than was ever obtained before for this cluster. For seven of these stars we also obtained spectra in circular polarization and applied the LSD technique to constrain the longitudinal magnetic field. Results. No magnetic field was detected in any of the analysed stars. HD 73666, a Blue Straggler previously considered as an Ap (Si) star, turns out to have the abundances of a normal A-type star. Am classification is not confirmed for HD 72942. For HD 73709 we have also calculated synthetic Aa photometry that is in good agreement with the observations. There is a generally good agreement between abundance predictions of diffusion models and values that we have obtained for the remaining Am stars. However, the observed Na and S abundances deviate from the predictions by 0.6 dex and ≥0.25 dex respectively. Li appears to be overabundant in three stars of our sample.

  • 21. Fossati, L.
    et al.
    Folsom, C. P.
    Bagnulo, S.
    Grunhut, J. H.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Landstreet, J. D.
    Paladini, C.
    Wade, G. A.
    A detailed spectroscopic analysis of the open cluster NGC 54602011In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 413, no 2, p. 1132-1144Article in journal (Refereed)
    Abstract [en]

    Within the context of a large project aimed at studying early F-, A- and late B-type stars, we present the abundance analysis of the photospheres of 21 members of the open cluster NGC 5460, an intermediate-age cluster (log t similar to 8.2) previously not studied with spectroscopy. Our study is based on medium- and high-resolution spectra obtained with the Fibre Large Array Multi Element Spectrograph (FLAMES) instrument of the European Southern Observatory/Very Large Telescope. We show that cluster members have a nearly solar metallicity and that there is evidence that the abundances of magnesium and iron are correlated with the effective temperature, exhibiting a maximum around T-eff = 10 500 K. No correlations are found between abundances and projected equatorial velocity, except for marginal evidence of barium being more abundant in slower than in faster rotating stars. We discovered two He-weak stars and a binary system where the hotter component is an HgMn star. We provide new estimates for the cluster distance (720 +/- 50 pc), age (log t = 8.2 +/- 0.1) and mean radial velocity (-17.9 +/- 5.2 km s-1).

  • 22. Fossati, L.
    et al.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Jenkins, J. S.
    Stancliffe, R. J.
    Haswell, C. A.
    Elmasli, A.
    Nickson, E.
    Detection of a magnetic field in three old and inactive solar-like planet-hosting stars2013In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 551, p. A85-Article in journal (Refereed)
    Abstract [en]

    Aims. Our understanding of magnetic fields in late-type stars is strongly driven by what we know of the solar magnetic field. For this reason, it is crucial to understand how typical the solar dynamo is. To do this we need to compare the solar magnetic field with that of other stars as similar to the Sun as possible, both in stellar parameters and age, hence activity. We present here the detection of a magnetic field in three planet-hosting solar-like stars having a mass, age, and activity level comparable to that of the Sun. Methods. We used the HARPSpol spectropolarimeter to obtain high-resolution high-quality circularly polarised spectra of HD 70642, HD 117207, and HD 154088, using the least-squares deconvolution technique to detect the magnetic field. From the Stokes I spectra, we calculated the log R'(HK) activity index for each star. We compared the position of the stars in the Hertzsprung-Russell diagram to evolutionary tracks, to estimate their mass and age. We used the lithium abundance, derived from the Stokes I spectra, to further constrain the ages. Results. We obtained a definite magnetic field detection for both HD 70642 and HD 154088, while for HD 117207 we obtained a marginal detection. Due to the lower signal-to-noise ratio of the observations, we were unable to detect the magnetic field in the second set of observations available for HD 117207 and HD 154088. On the basis of effective temperature, mass, age, and activity level the three stars can be considered solar analogs. Conclusions. HD 70642, HD 117207, and HD 154088 are ideal targets for a comparative study between the solar magnetic field and that of solar analogs.

  • 23. Fossati, L.
    et al.
    Kolenberg, K.
    Shulyak, D. V.
    Elmasli, A.
    Tsymbal, V.
    Barnes, T. G.
    Guggenberger, E.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    An in-depth spectroscopic analysis of RR Lyr Variations over the pulsation cycle2014In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 445, no 4, p. 4094-4104Article in journal (Refereed)
    Abstract [en]

    The stellar parameters of RR Lyrae stars vary considerably over a pulsation cycle, and their determination is crucial for stellar modelling. We present a detailed spectroscopic analysis of the pulsating star RR Lyr, the prototype of its class, over a complete pulsation cycle, based on high-resolution spectra collected at the 2.7-m telescope of McDonald Observatory. We used simultaneous photometry to determine the accurate pulsation phase of each spectrum and determined the effective temperature, the shape of the depth-dependent microturbulent velocity, and the abundance of several elements, for each phase. The surface gravity was fixed to 2.4. Element abundances resulting from our analysis are stable over the pulsation cycle. However, a variation in ionization equilibrium is observed around minimum radius. We attribute this mostly to a dynamical acceleration contributing to the surface gravity. Variable turbulent convection on time-scales longer than the pulsation cycle has been proposed as a cause for the Blazhko effect. We test this hypothesis to some extent by using the derived variable depth-dependent microturbulent velocity profiles to estimate their effect on the stellar magnitude. These effects turn out to be wavelength dependent and much smaller than the observed light variations over the Blazhko cycle: if variations in the turbulent motions are entirely responsible for the Blazhko effect, they must surpass the scales covered by the microturbulent velocity. This work demonstrates the possibility of a self-consistent spectroscopic analysis over an entire pulsation cycle using static atmosphere models, provided one takes into account certain features of a rapidly pulsating atmosphere.

  • 24.
    Grunhut, J. H.
    et al.
    European Southern Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany.;Univ Toronto, Dunlap Inst Astron & Astrophys, 50 St George St, Toronto, ON M5S 3H4, Canada..
    Wade, G. A.
    Royal Mil Coll Canada, Dept Phys, POB 17000, Kingston, ON K7K 7B4, Canada..
    Neiner, C.
    Univ Paris Diderot, UPMC Univ Paris 06, Sorbonne Univ,Sorbonne Paris Cite, LESIA,Observ Paris,PSL Res Univ,CNRS, 5 Pl Jules Janssen, F-92195 Meudon, France..
    Oksala, M. E.
    Univ Paris Diderot, UPMC Univ Paris 06, Sorbonne Univ,Sorbonne Paris Cite, LESIA,Observ Paris,PSL Res Univ,CNRS, 5 Pl Jules Janssen, F-92195 Meudon, France.;Calif Lutheran Univ, Dept Phys, 60 West Olsen Rd 3700, Thousand Oaks, CA 91360 USA..
    Petit, V.
    Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA..
    Alecian, E.
    Univ Paris Diderot, UPMC Univ Paris 06, Sorbonne Univ,Sorbonne Paris Cite, LESIA,Observ Paris,PSL Res Univ,CNRS, 5 Pl Jules Janssen, F-92195 Meudon, France.;CNRS, INSU, UJF Grenoble 1, Inst Planetol & Astrophys Grenoble,UMR 5274, F-38041 Grenoble, France..
    Bohlender, D. A.
    Natl Res Council Canada, Herzberg Astron & Astrophys Program, Domin Astrophys Observ, 5071 West Saanich Rd, Victoria, BC V9E 2E7, Canada..
    Bouret, J. -C
    Henrichs, H. F.
    Univ Amsterdam, Anton Pannekoek Inst Astron, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands..
    Hussain, G. A. J.
    European Southern Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany..
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    The MiMeS survey of Magnetism in Massive Stars: magnetic analysis of the O-type stars2017In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 465, no 2, p. 2432-2470Article in journal (Refereed)
    Abstract [en]

    We present the analysis performed on spectropolarimetric data of 97 O-type targets included in the framework of the Magnetism in Massive Stars (MiMeS) Survey. Mean least-squares deconvolved Stokes I and V line profiles were extracted for each observation, from which we measured the radial velocity, rotational and non-rotational broadening velocities, and longitudinal magnetic field B-l. The investigation of the Stokes I profiles led to the discovery of two new multiline spectroscopic systems (HD 46106, HD 204827) and confirmed the presence of a suspected companion in HD 37041. We present a modified strategy of the leastsquares deconvolution technique aimed at optimizing the detection of magnetic signatures while minimizing the detection of spurious signatures in Stokes V. Using this analysis, we confirm the detection of a magnetic field in six targets previously reported as magnetic by the MiMeS collaboration (HD 108, HD 47129A2, HD 57682, HD 148937, CPD-28 2561, and NGC 1624-2), as well as report the presence of signal in Stokes V in three new magnetic candidates (HD 36486, HD 162978, and HD 199579). Overall, we find a magnetic incidence rate of 7 +/- 3 per cent, for 108 individual O stars (including all O-type components part of multiline systems), with a median uncertainty of the B-l measurements of about 50 G. An inspection of the data reveals no obvious biases affecting the incidence rate or the preference for detecting magnetic signatures in the magnetic stars. Similar to A- and B-type stars, we find no link between the stars' physical properties (e.g. T-eff, mass, and age) and the presence of a magnetic field. However, the Of?p stars represent a distinct class of magnetic O-type stars.

  • 25.
    Hackman, T.
    et al.
    Univ Helsinki, Dept Phys, POB 64, Helsinki 00084, Finland..
    Lehtinen, J.
    Univ Helsinki, Dept Phys, POB 64, Helsinki 00084, Finland..
    Rosén, Lisa
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Kapyla, M. J.
    Aalto Univ, Dept Comp Sci, ReSoLVE Ctr Excellence, POB 15400, Aalto 00076, Finland..
    Zeeman-Doppler imaging of active young solar-type stars2016In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 587, article id A28Article in journal (Refereed)
    Abstract [en]

    Context: By studying young magnetically active late-type stars, i.e. analogues to the young Sun, we can draw conclusions on the evolution of the solar dynamo.

    Aims: We determine the topology of the surface magnetic field and study the relation between the magnetic field and cool photospheric spots in three young late-type stars.

    Methods: High-resolution spectropolarimetry of the targets was obtained with the HARPSpol instrument mounted at the ESO 3.6 m telescope. The signal-to-noise ratios of the Stokes IV measurements were boosted by combining the signal from a large number of spectroscopic absorption lines through the least squares deconvolution technique. Surface brightness and magnetic field maps were calculated using the Zeeman-Doppler imaging technique.

    Results: All three targets show clear signs of magnetic fields and cool spots. Only one of the targets, V1358 Ori, shows evidence of the dominance of non-axisymmetric modes. In two of the targets, the poloidal field is significantly stronger than the toroidal one, indicative of an alpha(2)-type dynamo, in which convective turbulence effects dominate over the weak differential rotation. In two of the cases there is a slight anti-correlation between the cool spots and the strength of the radial magnetic field. However, even in these cases the correlation is much weaker than in the case of sunspots.

    Conclusions: The weak correlation between the measured radial magnetic field and cool spots may indicate a more complex magnetic field structure in the spots or spot groups involving mixed magnetic polarities. Comparison with a previously published magnetic field map shows that on one of the stars, HD 29615, the underlying magnetic field changed its polarity between 2009 and 2013.

  • 26. Hackman, T.
    et al.
    Mantere, M. J.
    Jetsu, L.
    Ilyin, I.
    Kajatkari, P.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Lehtinen, J.
    Lindborg, M.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Tuominen, I.
    Spot activity of II Peg2011In: Astronomical Notes - Astronomische Nachrichten, ISSN 0004-6337, E-ISSN 1521-3994, Vol. 332, no 9-10, p. 859-865Article in journal (Refereed)
    Abstract [en]

    We have studied the long-term spot activity of the RS CVn star II Peg by means of Doppler imaging based on spectroscopy and time series analysis of photometry. We present 28 Doppler imaging temperature maps spanning the years 1994-2010, of which 14 were calculated for the present study. The longitudinal spot distribution, derived from the surface temperature maps, is compared with epochs of the light curve minima, derived from photometric observations. We detect a longitudinal drift in the major spot structure during 1995-2003. After this there is a clear decrease in the activity level and no clear drift can be seen. We conclude that the variations could be caused by a cyclic behaviour of the underlying magnetic dynamo.

  • 27. Hackman, T.
    et al.
    Mantere, M. J.
    Lindborg, M.
    Ilyin, I.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Tuominen, I.
    Doppler images of II Pegasi for 2004-20102012In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 538, p. A126-Article in journal (Refereed)
    Abstract [en]

    Aims. We study the spot activity of II Peg during the years 2004-2010 to determine long- and short-term changes in the magnetic activity. In a previous study, we detected a persistent active longitude, as well as major changes in the spot configuration occurring on a timescale of shorter than a year. The main objective of this study is to determine whether the same phenomena persist in the star during these six years of spectroscopic monitoring. Methods. The observations were collected with the high-resolution SOFIN spectrograph at the Nordic Optical Telescope. The temperature maps were calculated using a Doppler imaging code based on Tikhonov regularization. Results. We present 12 new temperature maps that show spots distributed mainly over high and intermediate latitudes. In each image, 1-3 main active regions can be identified. The activity level of the star is clearly lower than during our previous study for the years 1994-2002. In contrast to the previous observations, we detect no clear drift of the active regions with respect to the rotation of the star. Conclusions. Having shown a systematic longitudinal drift of the spot-generating mechanism during 1994-2002, the star has clearly switched to a low-activity state for 2004-2010, during which the spot locations appear more random over phase space. It could be that the star is near to a minimum of its activity cycle.

  • 28. Johns-Krull, Christopher M.
    et al.
    Chen, Wei
    Valenti, Jeff A.
    Jeffers, Sandra V.
    Piskunov, Nikolai E.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Makaganiuk, Vitalii
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Stempels, Eric
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Snik, Frans
    Keller, Christoph
    Rodenhuis, M.
    Magnetically Controlled Accretion on the Classical T Tauri Stars GQ Lupi and TW Hydrae2013In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 765, no 1, p. 11-Article in journal (Refereed)
    Abstract [en]

    We present high spectral resolution (R approximate to 108,000) Stokes V polarimetry of the classical T Tauri stars (CTTSs) GQ Lup and TW Hya obtained with the polarimetric upgrade to the HARPS spectrometer on the ESO 3.6 m telescope. We present data on both photospheric lines and emission lines, concentrating our discussion on the polarization properties of the He I emission lines at 5876 angstrom and 6678 angstrom. The He I lines in these CTTSs contain both narrow emission cores, believed to come from near the accretion shock region on these stars, and broad emission components which may come from either a wind or the large-scale magnetospheric accretion flow. We detect strong polarization in the narrow component of the two He I emission lines in both stars. We observe a maximum implied field strength of 6.05 +/- 0.24 kG in the 5876 angstrom line of GQ Lup, making it the star with the highest field strength measured in this line for a CTTS. We find field strengths in the two He I lines that are consistent with each other, in contrast to what has been reported in the literature on at least one star. We do not detect any polarization in the broad component of the He I lines on these stars, strengthening the conclusion that they form over a substantially different volume relative to the formation region of the narrow component of the He I lines.

  • 29. Joshi, S.
    et al.
    Ryabchikova, T.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Sachkov, M.
    Tiwari, S. K.
    Chakradhari, N. K.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Time-resolved photometric and spectroscopic analysis of the luminous Ap star HD 1034982010In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 401, no 2, p. 1299-1307Article in journal (Refereed)
    Abstract [en]

    We present the results of the photometric and spectroscopic monitoring of the luminous Ap star HD 103498. The time-series photometric observations were carried out on 17 nights using a three-channel fast photometer attached to the 1.04-m optical telescope at the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital. The photometric data from five nights in 2007 show a clear signature of 15-min periodicity. However, the follow-up observations during 2007-2009 did not reproduce any such periodicity. To confirm the photometric light variations, time-series spectroscopic observations were carried out with the 2.56-m Nordic Optical Telescope (NOT) at La Palma on 2009 February 2. No radial velocity variations were present in this data set, which is in full agreement with the photometric observations taken around the same date. Model atmosphere and abundance analysis of HD 103498 show that the star is evolved from the main sequence and its atmospheric abundances are similar to those of two other evolved Ap stars, HD 133792 and HD 204411: large overabundances of Si, Cr and Fe and moderate overabundances of the rare-earth elements. These chemical properties and a higher effective temperature distinguish HD 103498 from any known roAp star.

  • 30.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Diagnostic of stellar magnetic fields with cumulative circular polarisation profiles2015In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 580, article id A39Article in journal (Refereed)
    Abstract [en]

    Information about stellar magnetic field topologies is obtained primarily from hi.gh-resolution circular polarisation (Stokes V) observations. Because of their generally complex morphologies, the stellar Stokes V profiles are usually interpreted with elaborate inversion techniques such as Zeeman Doppler imaging (ZDI). Here we further develop a new method for interpreting circular polarisation signatures in spectral lines using cumulative Stokes V profiles (anti-derivative of Stokes V. This method is complimentary to ZDI and can be applied to validate the inversion results or when the available observational data are insufficient for an inversion. Based on the rigorous treatment of polarised line formation in the weak-field regime, we show that, for rapidly rotating stars, the cumulative Stokes V profiles contain information about the spatially resolved longitudinal magnetic field density. Rotational modulation of these profiles can be employed for a simple, qualitative characterisation of the stellar magnetic field topologies. We apply this diagnostic method to the archival observations of the weak-line T Tauri star V410 Tau and Bp He-strong star HD 37776. We show that the magnetic field in V410 Tau is dominated by an azimuthal component, in agreement with the ZDI map that we recover from the same data set. For HD 37776 the cumulative Stokes V profile variation indicates the presence of multiple regions of positive and negative field polarity. This behaviour agrees with the ZDI results, but contradicts the popular hypothesis that the magnetic field of this star is dominated by an axisymmetric quadrupolar component.

  • 31.
    Kochukhov, Oleg
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Magnetic fields in A stars besides Ap stars2014In: PUTTING A STARS INTO CONTEXT: EVOLUTION, ENVIRONMENT, AND RELATED STARS, 2014, p. 389-397Conference paper (Refereed)
    Abstract [en]

    I review ongoing efforts to understand the incidence of magnetism in intermediate-mass stars that are different from the magnetic Ap stars. This includes the search for magnetic fields in chemically peculiar stars of the Am and HgMn types as well as in normal A and late-B stars. I discuss different techniques for detecting weak stellar magnetic fields, and present a critical evaluation of recent magnetic detections in non-Ap stars. Special attention is given to the magnetic status of HgMn stars and to the discovery of weak polarization signatures in Sirius and Vega.

  • 32.
    Kochukhov, Oleg
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics. Department of Physics and Astronomy, Observational Astronomy.
    Observations of pulsations in roAp stars2007In: Vienna Workshop on the Future of Asteroseismology, 2007, p. 39-Conference paper (Refereed)
  • 33.
    Kochukhov, Oleg
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics. Department of Physics and Astronomy, Observational Astronomy.
    Spectropolarimetry of magnetic hot stars2007In: 4th Solar Polarization Workshop, 2007, p. 345-Conference paper (Other scientific)
  • 34.
    Kochukhov, Oleg
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics. Department of Physics and Astronomy, Observational Astronomy.
    Spectroscopic study of the pulsations in the roAp star HD 247122006In: JENAM 2005, 2006, p. 97-Conference paper (Refereed)
  • 35.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Astronomy and Space Physics.
    Adelman, S.J.
    Gulliver, A.F.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Astronomy and Space Physics.
    Weather in stellar atmosphere revealed by the dynamics of mercury clouds in alpha Andromedae2007In: Nature Physics, ISSN 1745-2473, E-ISSN 1745-2481, Vol. 3, no 8, p. 526-529Article in journal (Refereed)
    Abstract [en]

    The formation of long-lasting structures at the surfaces of stars is commonly ascribed to the action of strong magnetic fields. This paradigm is supported by observations of evolving cool spots in the Sun and active late-type stars, and stationary chemical spots in the early-type magnetic stars. However, results of our seven-year monitoring of mercury spots in non-magnetic early-type star αAndromedae show that the picture of magnetically driven structure formation is fundamentally incomplete. Using an indirect stellar-surface mapping technique, we construct a series of two-dimensional images of starspots and discover a secular evolution of the mercury cloud cover in this star. This remarkable structure-formation process, observed for the first time in any star, is plausibly attributed to a non-equilibrium, dynamical evolution of the heavy-element clouds created by atomic diffusion, and may have the same underlying physics as the weather patterns on terrestrial and giant planets.

  • 36.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Alentiev, D.
    Ryabchikova, T.
    Boyko, S.
    Cunha, M.
    Tsymbal, V.
    Weiss, W.
    Discovery of new rapidly oscillating Ap pulsators in the UVES survey of cool magnetic Ap stars2013In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 431, no 3, p. 2808-2819Article in journal (Refereed)
    Abstract [en]

    We have carried out a survey of short-period pulsations among a sample of carefully chosen cool Ap stars using time-resolved observations with the Ultraviolet and Visual Echelle Spectrograph at the European Southern Observatory ESO 8 m Very Large Telescope. Here, we report the discovery of pulsations with amplitudes 50-100 m s(-1) and periods 7-12 min in HD 132205, HD 148593 and HD 151860. These objects are therefore established as new rapidly oscillating Ap (roAp) stars. In addition, we independently confirm the presence of pulsations in HD 69013, HD 96237 and HD 143487 and detect, for the first time, radial velocity oscillations in two previously known photometric roAp stars HD 119027 and HD 185256. At the same time, no pulsation variability is found for HD 5823, HD 178892 and HD 185204. All of the newly discovered roAp stars were previously classified as non-pulsating based on the low-precision ground-based photometric surveys. This shows that such observations cannot be used to reliably distinguish between pulsating and non-pulsating stars and that all cool Ap stars may harbour p-mode pulsations of different amplitudes.

  • 37.
    Kochukhov, Oleg
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics. Department of Physics and Astronomy, Observational Astronomy.
    Freytag, Bernd
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics. Department of Physics and Astronomy, Observational Astronomy.
    Piskunov, Nikolai
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics. Department of Physics and Astronomy, Observational Astronomy.
    Steffen, M.
    3-D Hydrodynamic Simulation of Convection in A Stars2006In: IAUS 239, Convection in Astrophysics, 2006, p. 169-Conference paper (Other scientific)
  • 38.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Heiter, Ulrike
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Ryde, N.
    Gustafsson, B.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Bagnulo, S.
    Plez, B.
    Magnetic fields in M dwarf stars from high-resolution infrared spectra2009In: COOL STARS, STELLAR SYSTEMS AND THE SUN: Proceedings of the 15th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, 2009, Vol. 1094, p. 124-129Conference paper (Refereed)
    Abstract [en]

    Magnetic fields play a central role in the atmospheric properties and variability of active M dwarfs. Information on the strength and structure of magnetic fields in these objects is vital for understanding dynamo mechanisms and magnetically-driven activity of low-mass stars, and for constraining theories of star formation and evolution. We have initiated the first systematic high-resolution survey of magnetically sensitive infrared spectral lines in M dwarf stars using the CRIRES instrument at the ESO VLT. We have completed observations for a sample of 35 active and inactive M dwarfs. Here we report first results of our project, demonstrating a clear detection of magnetic splitting of lines in the spectra of several M dwarfs. We assess diagnostic potential of different Zeeman-sensitive lines in the observed spectral region and apply spectrum synthesis modelling to infer magnetic field properties of selected M dwarfs.

  • 39.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Lavail, Alexis
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    The Global and Small-scale Magnetic Fields of Fully Convective, Rapidly Spinning M Dwarf Pair GJ65 A and B2017In: Astrophysical Journal Letters, ISSN 2041-8205, E-ISSN 2041-8213, Vol. 835, no 1, article id L4Article in journal (Refereed)
    Abstract [en]

    The nearby M dwarf binary GJ65 AB, also known as BL. Cet and UV. Cet, is a unique benchmark for investigation of dynamo-driven activity of low-mass stars. Magnetic activity of GJ65 was repeatedly assessed by indirect means, such as studies of flares, photometric variability, X-ray, and radio emission. Here, we present a direct analysis of large-scale and local surface magnetic fields in both components. Interpreting high-resolution circular polarization spectra (sensitive to a large-scale field geometry) we uncovered a remarkable difference of the global stellar field topologies. Despite nearly identical masses and rotation rates, the secondary exhibits an axisymmetric, dipolar-like global field with an average strength of 1.3. kG while the primary has a much weaker, more complex, and non-axisymmetric 0.3. kG field. On the other hand, an analysis of the differential Zeeman intensification (sensitive to the total magnetic flux) shows the two stars having similar magnetic fluxes of 5.2 and 6.7. kG for GJ65 A and B, respectively, although there is evidence that the field strength distribution in GJ65 B is shifted toward a higher field strength compared to GJ65 A. Based on these complementary magnetic field diagnostic results, we suggest that the dissimilar radio and X-ray variability of GJ65 A and B is linked to their different global magnetic field topologies. However, this difference appears to be restricted to the upper atmospheric layers but does not encompass the bulk of the stars and has no influence on the fundamental stellar properties.

  • 40.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Lueftinger, T.
    Neiner, C.
    Alecian, E.
    Magnetic field topology of the unique chemically peculiar star CU Virginis2014In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 565, p. A83-Article in journal (Refereed)
    Abstract [en]

    Context. The late-B, magnetic, chemically peculiar star CU Vir is one of the fastest rotators among the intermediate-mass stars with strong fossil magnetic fields. It shows a prominent rotational modulation of the spectral energy distribution and absorption line profiles due to chemical spots and exhibits a unique, strongly beamed variable radio emission. Aims. Little is known about the magnetic field topology of CU Vir. In this study, we aim to derive detailed maps of the magnetic field distribution over the surface of this star for the first time. Methods. We use high-resolution spectropolarimetric observations covering the entire rotational period. These data are interpreted using a multi-line technique of least-squares deconvolution (LSD) and a new Zeeman Doppler imaging code, which is based on detailed polarised radiative transfer modelling of the Stokes I and V LSD profiles. This new magnetic inversion approach relies on the spectrum synthesis calculations over the full wavelength range that is covered by observations and does not assume that the LSD profiles behave as a single spectral line with mean parameters. Results. We present magnetic and chemical abundance maps derived from the Si and Fe lines. Mean polarisation profiles of both elements reveal a significant departure of CU Vir's magnetic field topology from the commonly assumed axisymmetric dipolar configuration. The field of CU Vir is dipolar-like but clearly non-axisymmetric, showing a large difference in the field strength between the regions of opposite polarity. The main relative abundance depletion features in both Si and Fe maps coincide with the weak-field region in the magnetic map. Conclusions. The detailed information on the distorted dipolar magnetic field topology of CU Vir provided by our study is essential for understanding chemical spot formation, radio emission, and rotational period variation of this star.

  • 41.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Lundin, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Romanyuk, Iosif
    Kudryavtsev, Dmitry
    The extraordinary complex magnetic field of the helium-strong star HD 377762011In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 726, no 1, p. 24-Article in journal (Refereed)
    Abstract [en]

    The early-type chemically peculiar stars often show strong magnetic fields on their surfaces. These magnetic topologies are organized on large scales and are believed to be close to an oblique dipole for most of the stars. In a striking exception to this general trend, the helium-strong star HD 37776 shows an extraordinary double-wave rotational modulation of the longitudinal magnetic field measurements, indicating a topologically complex and, possibly, record-strong magnetic field. Here we present a new investigation of the magnetic field structure of HD 37776, using both simple geometrical interpretation of the longitudinal field curve and detailed modeling of the time-resolved circular polarization line profiles with the help of a magnetic Doppler imaging technique. We derive a model of the magnetic field structure of HD 37776, which reconciles for the first time all magnetic observations available for this star. We find that the local surface field strength does not exceed approximate to 30 kG, while the overall field topology of HD 37776 is dominated by a non-axisymmetric component and represents by far the most complex magnetic field configuration found among early-type stars.

  • 42.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Makaganiuk, Vitalii
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Least-squares deconvolution of the stellar intensity and polarization spectra2010In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 524, no 1, p. A5-Article in journal (Refereed)
    Abstract [en]

    Context. Least-squares deconvolution (LSD) is a powerful method of extracting high-precision average line profiles from the stellar intensity and polarization spectra. This technique is widely used for detection, characterization, and detailed mapping of the temperature, magnetic, and chemical abundance structures on the surfaces of stars. Aims. Despite its common usage, the LSD method is poorly documented and has never been tested with realistic synthetic spectra. In this study we revisit the key assumptions of the LSD technique, clarify its numerical implementation, discuss possible improvements and give recommendations of how to make LSD results understandable and reproducible. We also address the problem of interpretation of the moments and shapes of the LSD profiles in terms of physical parameters. Methods. We have developed an improved, multiprofile version of LSD (iLSD) and have extended the deconvolution procedure to linear polarization analysis taking into account anomalous Zeeman splitting of spectral lines. The iLSD method is applied to the theoretical Stokes parameter spectra computed for a wide wavelength interval containing all relevant spectral lines. We test various methods of interpreting the mean profiles, investigating how coarse approximations of the multiline technique translate into errors of the derived parameters. Results. We find that, generally, the Stokes parameter LSD profiles do not behave as a real spectral line with respect to the variation of magnetic field and elemental abundance. This problem is especially prominent for the Stokes I (intensity) variation with abundance and Stokes Q (linear polarization) variation with magnetic field. At the same time, the Stokes V (circular polarization) LSD spectra closely resemble the profile of a properly chosen synthetic line for the magnetic field strength up to 1 kG. The longitudinal field estimated from the Stokes V LSD profile is accurate to within 10% for the field strength below 5 kG and to within a few percent for the fields weaker than 1 kG. Our iLSD technique offers clear advantages over the standard LSD method in the individual analysis of different chemical elements. Conclusions. We conclude that the usual method of interpreting the LSD profiles by assuming that they are equivalent to a real spectral line gives satisfactory results only in a limited parameter range and thus should be applied with caution. A more trustworthy approach is to abandon the single-line approximation of the average profiles and apply LSD consistently to observations and synthetic spectra.

  • 43.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Makaganiuk, Vitalii
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Jeffers, S. V.
    Johns-Krull, C. M.
    Keller, C. U.
    Rodenhuis, M.
    Snik, F.
    Stempels, H. C.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Valenti, J. A.
    Are there tangled magnetic fields on HgMn stars?2013In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 554, p. A61-Article in journal (Refereed)
    Abstract [en]

    Context. Several recent spectrophotometric studies failed to detect significant global magnetic fields in late-B HgMn chemically peculiar stars, but some investigations have suggested the presence of strong unstructured or tangled fields in these objects. Aims. We used detailed spectrum synthesis analysis to search for evidence of tangled magnetic fields in high-quality observed spectra of eight slowly rotating HgMn stars and one normal late-B star. We also evaluated recent sporadic detections of weak longitudinal magnetic fields in HgMn stars based on the moment technique. Methods. Our spectrum synthesis code calculated the Zeeman broadening of metal lines in HARPS spectra, assuming an unstructured, turbulent magnetic field. A simple line formation model with a homogeneous radial field distribution was applied to assess compatibility between previous longitudinal field measurements and the observed mean circular polarization signatures. Results. Our analysis of the Zeeman broadening of magnetically sensitive spectral lines reveals no evidence of tangled magnetic fields in any of the studied HgMn or normal stars. We infer upper limits of 200-700 G for the mean magnetic field modulus - much smaller than the field strengths implied by studies based on differential magnetic line intensification and quadratic field diagnostics. The new HARPSpol longitudinal field measurements for the extreme HgMn star HD65949 and the normal late-B star 21 Peg are consistent with zero at a precision of 3-6 G. Re-analysis of our Stokes V spectra of the spotted HgMn star HD11753 shows that the recent moment technique measurements retrieved from the same data are incompatible with the lack of circular polarization signatures in the spectrum of this star. Conclusions. We conclude that there is no evidence for substantial tangled magnetic fields on the surfaces of studied HgMn stars. We cannot independently confirm the presence of very strong quadratic or marginal longitudinal fields for these stars, so results from the moment technique are likely to be spurious.

  • 44.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Makaganiuk, Vitalii
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Jeffers, S. V.
    Johns-Krull, C. M.
    Keller, C. U.
    Rodenhuis, M.
    Snik, F.
    Stempels, Henricus C.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Valenti, J. A.
    No magnetic field in the spotted HgMn star mu Leporis2011In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 534, p. L13-Article in journal (Refereed)
    Abstract [en]

    Context. Chemically peculiar stars of the mercury-manganese (HgMn) type represent a new class of spotted late-B stars, in which evolving surface chemical inhomogeneities are apparently unrelated to the presence of strong magnetic fields but are produced by some hitherto unknown astrophysical mechanism.

    Aims. The goal of this study is to perform a detailed line profile variability analysis and carry out a sensitive magnetic field search for one of the brightest HgMn stars -mu Lep.

    Methods. We acquired a set of very high-quality intensity and polarization spectra of mu Lep with the HARPSpol polarimeter. These data were analyzed with the multiline technique of least-squares deconvolution in order to extract information on the magnetic field and line profile variability.

    Results. Our spectra show very weak but definite variability in the lines of Sc, all Fe-peak elements represented in the spectrum of mu Lep, as well as Y, Sr, and Hg. Variability might also be present in the lines of Si and Mg. Anomalous profile shapes of Ti II and YII lines suggest a dominant axisymmetric distribution of these elements. At the same time, we found no evidence of the magnetic field in mu Lep, with the 3 sigma upper limit of only 3 G for the mean longitudinal magnetic field. This is the most stringent upper limit on the possible magnetic field derived for a spotted HgMn star.

    Conclusions. The very weak variability detected for many elements in the spectrum mu Lep suggests that low-contrast chemical inhomogeneities may be common in HgMn stars and that they have not been recognized until now due to the limited precision of previous spectroscopic observations and a lack of time-series data. The null result of the magnetic field search reinforces the conclusion that formation of chemical spots in HgMn stars is not magnetically driven.

  • 45.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Makaganiuk, Vitalii
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Snik, F.
    Jeffers, S. V.
    Johns-Krull, C. M.
    Keller, C. U.
    Rodenhuis, M.
    Valenti, J. A.
    First detection of linear polarization in the line profiles of active cool stars2011In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 732, no 2, p. L19-Article in journal (Refereed)
    Abstract [en]

    The application of high-resolution spectropolarimetry has led to major progress in understanding the magnetism and activity of late-type stars. During the last decade, magnetic fields have been discovered and mapped for many types of active cool stars using spectropolarimetric data. However, these observations and modeling attempts are fundamentally incomplete since they are based on the interpretation of the circular polarization alone. Taking advantage of the newly built HARPS polarimeter, we have obtained the first systematic observations of several cool active stars in all four Stokes parameters. Here we report the detection of magnetically induced linear polarization for the primary component of the very active RS CVn binary HR 1099 and for the moderately active K dwarf epsilon Eri. For both stars the amplitude of linear polarization signatures is measured to be similar to 10(-4) of the unpolarized continuum, which is approximately a factor of 10 lower than for circular polarization. This is the first detection of the linear polarization in line profiles of cool active stars. Our observations of the inactive solar-like star alpha Cen A show neither circular nor linear polarization above the level of similar to 10(-5), indicating the absence of a net longitudinal magnetic field stronger than 0.2 G.

  • 46.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Mantere, M. J.
    Hackman, T.
    Ilyin, I.
    Magnetic field topology of the RS CVn star II Pegasi2013In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 550, p. A84-Article in journal (Refereed)
    Abstract [en]

    Context. The dynamo processes in cool active stars generate complex magnetic fields responsible for prominent surface stellar activity and variability at different time scales. For a small number of cool stars magnetic field topologies were reconstructed from the time series of spectropolarimetric observations using the Zeeman Doppler imaging (ZDI) method, often yielding surprising and controversial results. Aims. In this study we follow a long-term evolution of the magnetic field topology of the RS CVn binary star II Peg using a more self-consistent and physically more meaningful modelling approach compared to previous ZDI studies. Methods. We collected high-resolution circular polarisation observations of II Peg using the SOFIN spectropolarimeter at the Nordic Optical Telescope. These data cover 12 epochs spread over 7 years, comprising one of the most comprehensive spectropolarimetric data sets acquired for a cool active star. A multi-line diagnostic technique in combination with a new ZDI code is applied to interpret these observations. Results. We have succeeded in detecting clear magnetic field signatures in average Stokes V profiles for all 12 data sets. These profiles typically have complex shapes and amplitudes of similar to 10(-3) of the unpolarised continuum, corresponding to mean longitudinal fields of 50-100 G. Magnetic inversions using these data reveals evolving magnetic fields with typical local strengths of 0.5-1.0 kG and complex topologies. Despite using a self-consistent magnetic and temperature mapping technique, we do not find a clear correlation between magnetic and temperature features in the ZDI maps. Neither do we confirm the presence of persistent azimuthal field rings found in other RS CVn stars. Reconstruction of the magnetic field topology of II Peg reveals significant evolution of both the surface magnetic field structure and the extended magnetospheric field geometry on the time scale covered by our observations. From 2004 to 2010 the total field energy drastically declined and the field became less axisymmetric. This also coincided with the transition from predominantly poloidal to mainly toroidal field topology. Conclusions. A qualitative comparison of the ZDI maps of II Peg with the prediction of dynamo theory suggests that the magnetic field in this star is produced mainly by the turbulent alpha(2) dynamo rather than the solar alpha Omega dynamo. Our results do not show a clear active longitude system, nor is there evidence of the presence of an azimuthal dynamo wave.

  • 47.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Petit, P.
    Univ Toulouse, UPS OMP, IRAP, Toulouse, France.;CNRS, Inst Rech Astrophys & Planetol, Toulouse, France..
    Strassmeier, K. G.
    Leibniz Inst Astrophys Potsdam AIP, Potsdam, Germany..
    Carroll, T. A.
    Leibniz Inst Astrophys Potsdam AIP, Potsdam, Germany..
    Fares, R.
    Osserv Astrofis Catania, INAF, Catania, Italy..
    Folsom, C. P.
    Univ Toulouse, UPS OMP, IRAP, Toulouse, France.;CNRS, Inst Rech Astrophys & Planetol, Toulouse, France..
    Jeffers, S. V.
    Georg August Univ Gottingen, Inst Astrophys, Gottingen, Germany..
    Korhonen, H.
    Univ Copenhagen, Niels Bohr Inst, Copenhagen, Denmark..
    Monnier, J. D.
    Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA..
    Morin, J.
    Univ Montpellier, CNRS, LUPM, Montpellier, France..
    Rosén, Lisa
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Roettenbacher, R. M.
    Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA.;Stockholm Univ, Dept Astron, Stockholm, Sweden..
    Shulyak, D.
    Georg August Univ Gottingen, Inst Astrophys, Gottingen, Germany..
    Surface magnetism of cool stars2017In: Astronomical Notes - Astronomische Nachrichten, ISSN 0004-6337, E-ISSN 1521-3994, Vol. 338, no 4, p. 428-441Article in journal (Refereed)
    Abstract [en]

    Magnetic fields are essential ingredients of many physical processes in the interiors and envelopes of cool stars. Yet their direct detection and characterization is notoriously difficult, requiring high-quality observations and advanced analysis techniques. Significant progress has been recently achieved by several types of direct magnetic field studies on the surfaces of cool, active stars. In particular, complementary techniques of field topology mapping with polarization data and total magnetic flux measurements from intensity spectra have been systematically applied to different classes of active stars, leading to interesting and occasionally controversial results. In this paper, we summarize the current status of direct magnetic field studies of cool stars and investigations of surface inhomogeneities caused by the field, based on the material presented at the Cool Stars 19 splinter session.

  • 48.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Rivinius, Thomas
    Oksala, Mary E.
    Romanyuk, Iosif
    Magnetic Doppler imaging of early-type stars2011In: Active OB stars: Structure, evolution, mass-loss, and critical limits / [ed] Neiner, C. et al., 2011, Vol. 272, p. 166-171Conference paper (Refereed)
    Abstract [en]

    Doppler imaging of early-type magnetic stars is the most advanced method to interpret their line profile variations. DI allows us to study directly a complex interplay between chemical spots, magnetic fields, and the mass loss. Here we outline the general principles of the surface mapping of stars, discuss adaption of this technique to early-type stars and present several recent examples of the abundance and magnetic mapping performed for rapidly rotating early-B stars. In particular, we present the first Doppler images for the very fast rotating He-rich star HR 7355 and a reconstruction of magnetic field for the well-known Bp star a On E. We also present new magnetic maps for the He-strong star HD 37776, which possesses one of the most complex magnetic field topologies among the upper main sequence stars.

  • 49.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Rusomarov, Naum
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Valenti, J. A.
    Stempels, H. C.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Snik, F.
    Rodenhuis, M.
    Piskunov, Nikolai
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Makaganiuk, V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Keller, C. U.
    Johns-Krull, C. M.
    Magnetic field topology and chemical spot distributions in the extreme Ap star HD 750492015In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 574, article id A79Article in journal (Refereed)
    Abstract [en]

    Context. Intermediate-mass, magnetic chemically peculiar (Ap) stars provide a unique opportunity to study the topology of stellar magnetic fields in detail and to investigate magnetically driven processes of spot formation. Aims. Here we aim to derive the surface magnetic field geometry and chemical abundance distributions for the extraordinary Ap star HD 75049. This object hosts a surface field of similar to 30 kG, one of the strongest known for any non-degenerate star. Methods. We used time-series of high-resolution HARPS intensity and circular polarisation observations. These data were interpreted with the help of magnetic Doppler imaging and model atmospheres incorporating effects of a non-solar chemical composition and a strong magnetic field. Results. Based on high-precision measurements of the mean magnetic field modulus, we refined the rotational period of HD 75049 to P-rot = 4.048267 +/- 0.000036 d. We also derived basic stellar parameters, T-eff = 10 250 +/- 250 K and log g = 4.3 +/- 0.1. Magnetic Doppler imaging revealed that the field topology of HD 75049 is poloidal and dominated by a dipolar contribution with a peak surface field strength of 39 kG. At the same time, deviations from the classical axisymmetric oblique dipolar configuration are significant. Chemical surface maps of Si, Cr, Fe, and Nd show abundance contrasts of 0.5-1.4 dex, which is low compared with many other Ap stars. Of the chemical elements, Nd is found to be enhanced close to the magnetic pole, whereas Si and Cr are concentrated predominantly at the magnetic equator. The iron distribution shows low-contrast features both at the magnetic equator and the pole. Conclusions. The morphology of the magnetic field and the properties of chemical spots in HD 75049 are qualitatively similar to those of Ap stars with weaker fields. Consequently, whatever mechanism forms and sustains global magnetic fields in intermediate-mass main-sequence stars, it operates in the same way over the entire observed range of magnetic field strengths.

  • 50.
    Kochukhov, Oleg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Observational Astronomy.
    Ryabchikova, T. A.
    Russian Acad Sci, Inst Astron, 48 Pyatnitskaya St, Moscow 119017, Russia..
    Putting atomic diffusion theory of magnetic ApBp stars to the test: evaluation of the predictions of time-dependent diffusion models2018In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 474, no 2, p. 2787-2795Article in journal (Refereed)
    Abstract [en]

    A series of recent theoretical atomic diffusion studies has address the challenging problem of predicting inhomogeneous vertical and horizontal chemical element distributions in the atmospheres of magnetic ApBp stars. Here we critically assess the most sophisticated of such diffusion models - based on a time-dependent treatment of the atomic diffusion in a magnetized stellar atmosphere - by direct comparison with observations as well by testing the widely used surface mapping tools with the spectral line profiles predicted by this theory. We show that the mean abundances of Fe and Cr are grossly underestimated by the time-dependent theoretical diffusion model, with discrepancies reaching a factor of 1000 for Cr. We also demonstrate that Doppler imaging inversion codes, based either on modelling of individual metal lines or line-averaged profiles simulated according to theoretical three-dimensional abundance distribution, are able to reconstruct correct horizontal chemical spot maps despite ignoring the vertical abundance variation. These numerical experiments justify a direct comparison of the empirical two-dimensional Doppler maps with theoretical diffusion calculations. This comparison is generally unfavourable for the current diffusion theory, as very few chemical elements are observed to form overabundance rings in the horizontal field regions as predicted by the theory and there are numerous examples of element accumulations in the vicinity of radial field zones, which cannot be explained by diffusion calculations.

123 1 - 50 of 126
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