On unstably stratified toroidal magnetic fields in stars
Abstract
A previous discussion of the stability of stars containing an axisymmetric toroidal magnetic field is extended and it is shown that there exist continuous perturbations which give a negative value of (delta) (W to the sigma power) when one of the conditions for stability is violated; this contradicts a conclusion reached by Dicke. The main characteristics of the displacement fields that are associated with the instabilities in the special, but astrophysically relevant, case of a weak toroidal field are indicated. In particular, axisymmetric toroidal magnetic fields with a strength of 100 million G in the cores of solar-type stars produce instabilities with e-folding times of the order of a few hours.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 1980
- DOI:
- 10.1093/mnras/193.4.833
- Bibcode:
- 1980MNRAS.193..833G
- Keywords:
-
- Dynamic Stability;
- Magnetic Field Configurations;
- Magnetohydrodynamic Stability;
- Stellar Magnetic Fields;
- Stellar Rotation;
- Displacement;
- Perturbation Theory;
- Toroids;
- Astrophysics