uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
The energy budget of stellar magnetic fields
Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife, Scotland..
Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife, Scotland..
Univ Geneva, Observ Geneve, CH-1290 Sauverny, Switzerland..
Show others and affiliations
2015 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 453, no 4, 4301-4310 p.Article in journal (Refereed) Published
Abstract [en]

Spectropolarimetric observations have been used to map stellar magnetic fields, many of which display strong bands of azimuthal fields that are toroidal. A number of explanations have been proposed to explain how such fields might be generated though none are definitive. In this paper, we examine the toroidal fields of a sample of 55 stars with magnetic maps, with masses in the range 0.1-1.5M(circle dot). We find that the energy contained in toroidal fields has a power-law dependence on the energy contained in poloidal fields. However the power index is not constant across our sample, with stars less and more massive than 0.5M(circle dot) having power indices of 0.72 +/- 0.08 and 1.25 +/- 0.06, respectively. There is some evidence that these two power laws correspond to stars in the saturated and unsaturated regimes of the rotation-activity relation. Additionally, our sample shows that strong toroidal fields must be generated axisymmetrically. The latitudes at which these bands appear depend on the stellar rotation period with fast rotators displaying higher latitude bands than slow rotators. The results in this paper present new constraints for future dynamo studies.

Place, publisher, year, edition, pages
2015. Vol. 453, no 4, 4301-4310 p.
Keyword [en]
techniques: polarimetric, stars: activity, stars: magnetic field, stars: rotation
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:uu:diva-267650DOI: 10.1093/mnras/stv1925ISI: 000363651600069OAI: oai:DiVA.org:uu-267650DiVA: diva2:874496
German Research Foundation (DFG)
Available from: 2015-11-27 Created: 2015-11-25 Last updated: 2015-11-27Bibliographically approved

Open Access in DiVA

fulltext(741 kB)26 downloads
File information
File name FULLTEXT01.pdfFile size 741 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Rosén, Lisa
By organisation
Department of Physics and Astronomy
In the same journal
Monthly notices of the Royal Astronomical Society
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
Total: 26 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 73 hits
ReferencesLink to record
Permanent link

Direct link