Nonlinear nonaxisymmetric dynamo models for cool stars
Abstract
Observational evidence for long-lived nonaxisymmetric features on the surfaces of rapidly rotating late-type giant stars (e.g., FK Comae and RS CVn stars) is beginning to be found. By analogy with sunspots, these features may be associated with large scale nonaxisymmetric magnetic field structures, generated by a dynamo operating in the convective envelopes. A nonlinear nonaxisymmetric dynamo model is described, and it is shown that for a simple 'alpha-quenching' nonlinearity together with suitable choices of underlying radial profiles of differential rotation and the alpha-effect, stable nonaxisymmetric solution can be found by numerical integration.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1991
- Bibcode:
- 1991A&A...245..129M
- Keywords:
-
- Cool Stars;
- Dynamo Theory;
- Giant Stars;
- Stellar Activity;
- Stellar Magnetic Fields;
- Stellar Rotation;
- Computational Astrophysics;
- Late Stars;
- Magnetic Field Configurations;
- Nonlinearity;
- Numerical Integration;
- Astrophysics