Angular momentum loss by a stellar wind and rotational velocities of white dwarfs
Abstract
A simple model which can explain the large angular momentum loss that a star suffers in its post-main-sequence evolution is presented. The basic assumptions are that main-sequence stars and white dwarfs rotate as rigid bodies and that the mass loss between the two stages is due to stellar winds. The angular momentum loss, even without considering braking effects of magnetic fields, turns out to be very large, with a lower limit which varies from 99 percent for a star which evolves into a 0.5-solar- mass white dwarf to more than 99.99 percent for a final mass higher than 1.1 solar mass. The theoretical upper limit to the rotational velocity of white dwarfs is set at 60 km/s, in very good agreement with observational values.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 1992
- DOI:
- 10.1093/mnras/257.3.450
- Bibcode:
- 1992MNRAS.257..450V
- Keywords:
-
- Angular Momentum;
- Stellar Evolution;
- Stellar Mass Ejection;
- Stellar Rotation;
- Stellar Winds;
- White Dwarf Stars;
- Main Sequence Stars;
- Stellar Mass;
- Stellar Models;
- Astrophysics