Investigating the possible connection between lambda Bootis stars and intermediate Population II type stars
2014 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 567, A67- p.Article in journal (Refereed) Published
Context The it Bootis stars are located at the upper maid sequence of the Hertzsprung-Russell diagram and exhibit a peculiar abundance pattern. The light elements (C, N, O, and S) present solar abundances whereas all other elements are moderately to strongly underabundant It has not yet been determined whether that abundance pattern is intrinsic, or is restricted to the stellar surface. Aims. If we follow the hypothesis that the A Bootis stars are intrinsically metal-weak, then there should be a connection with the intermediate Population II and F-weak objects. Such a possible affinity has not been previously investigated. Methods. We present detailed elemental abundances, including those of the light elements carbon and oxygen, for 38 bright intermediate Population If and F-weak objects. In addition, we investigate the kinematic characteristics of the groups, Results. From photometric. spectroscopic, and kinematic data, there is no distinction between the intermediate Population II and F-weak type stars. We therefore conclude that the two groups are identical. However, it is possible to distinguish the lambda Bootis stars from the intermediate Population II stars on the basis of elemental abundances though not in terms of their kinematics. Conclusions. The lambda Bootis stars seem to be distinct from the intermediate Population II group. Further asteroseisrnologic investigations and analyses of spectroscopic binary systems are needed to strengthen this conclusion.
Place, publisher, year, edition, pages
2014. Vol. 567, A67- p.
stars: abundances, stars: chemically peculiar, stars: early-type, stars: Population II
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:uu:diva-234212DOI: 10.1051/0004-6361/201423817ISI: 000341185300121OAI: oai:DiVA.org:uu-234212DiVA: diva2:755928