On the stability of toroidal flux tubes in differentially rotating stars
Abstract
The stability of magnetic flux tubes, located in the equatorial plane of a rotating star, is studied using the slender flux tube approximation. The effects of a longitudinal mass flow in the tubes and of a radial gradient of angular velocity in the surrounding medium are considered. It is shown that differential rotation has a dominant effect on the stability in the case of rapid rotation where the notation rate is much greater than the Alfven velocity divided by two pressure scale heights. Flux tubes are unstable (stable) if the angular velocity decreases (increases) with distance from the rotation axis. The apparent stability of toroidal flux tubes in the sun suggests that in the deep convective zone the angular velocity increases radially outward. This has important implications for stellar dynamo theories.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- February 1983
- Bibcode:
- 1983A&A...118..275V
- Keywords:
-
- Dynamic Stability;
- Dynamo Theory;
- Magnetic Flux;
- Mass Flow;
- Stellar Rotation;
- Angular Velocity;
- Equations Of Motion;
- Toroids;
- Astrophysics