The energy budget of stellar magnetic fields
Article
Article Title | The energy budget of stellar magnetic fields |
---|---|
ERA Journal ID | 1074 |
Article Category | Article |
Authors | See, V. (Author), Jardine, M. (Author), Vidotto, A. A. (Author), Donati, J.-F. (Author), Folsom, C. P. (Author), Boro Saikia, S. (Author), Bouvier, J. (Author), Fares, R. (Author), Gregory, S. G. (Author), Hussain, G. (Author), Jeffers, S. V. (Author), Marsden, S. C. (Author), Morin, J. (Author), Moutou, C. (Author), do Nascimento Jr., J. D. (Author), Petit, P. (Author), Rosen, L. (Author) and Waite, I. A. (Author) |
Journal Title | Monthly Notices of the Royal Astronomical Society |
Journal Citation | 453 (4), pp. 4301-4310 |
Number of Pages | 10 |
Year | 2015 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 0035-8711 |
1365-2966 | |
Digital Object Identifier (DOI) | https://doi.org/10.1093/mnras/stv1925 |
Web Address (URL) | https://academic.oup.com/mnras/article/453/4/4301/2593729 |
Abstract | 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 0.1-1.5 M⊙. 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 0.5 M⊙ 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. |
Keywords | techniques: polarimetric; stars: activity; stars: magnetic field; stars: rotation |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Byline Affiliations | University of St Andrews, United Kingdom |
University of Geneva, Switzerland | |
University of Toulouse, France | |
Grenoble Alpes University, France | |
Georg August University of Gottingen, Germany | |
National Institute of Astrophysics, Italy | |
European Southern Observatory (ESO), Germany | |
University of Gottingen, Germany | |
Computational Engineering and Science Research Centre | |
University of Montpellier, France | |
Marseille Observatory, France | |
Federal University of Rio Grande do Norte, Brazil | |
Uppsala University, Sweden | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q34w0/the-energy-budget-of-stellar-magnetic-fields
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