Volume 432, Number 1, March II 2005
|Page(s)||249 - 259|
|Section||Stellar structure and evolution|
|Published online||22 February 2005|
Nonaxisymmetric magnetic field generation in rapidly rotating late-type stars
School of Mathematics, University of Manchester, Manchester M13 9PL, UK e-mail: email@example.com
Accepted: 31 October 2004
Recently the discovery of the “flip-flop” phenomenon, by which a predominant “active” longitude jumps by about , on several rapidly rotating late-type stars has directed attention to the issues surrounding the presence of large-scale nonaxisymmetric magnetic fields in these objects. Here we study nonlinear mean field dynamo models with quasi-cylindrical rotation laws, acting in spherical shells. Stable nonaxisymmetric magnetic fields are found to be generated for a range of parameters and, for certain of these models, jumps in a measure plausibly related to the position of active longitudes are found to occur. In general, nonaxisymmetric fields appear to be easier to generate in thinner dynamo-active regions. However, flip-flops appear to be stronger for intermediate thicknesses of the dynamo-active shells.
Key words: magnetic fields / magnetohydrodynamics / stars: activity / stars: late-type / stars: rotation / stars: magnetic fields
© ESO, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.