The angular momentum history of the Hyades K giants.
Abstract
Measurements of the rotation velocities and macroturbulence dispersions in the four Hyades K giants are presented. The observed rotation is approximately 40% of that expected from evolutionary models in which convective envelopes are assumed to rotate as rigid bodies. It is possible to explain this discrepancy either by postulating that a magnetic braking has occurred or that the coupling is not strong enough to maintain rigid-body rotation in convective layers. Evolutionary models having uniform specific angular momentum in the convective layers are constructed and found to agree with the observed rotation rates.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1982
- DOI:
- 10.1086/159719
- Bibcode:
- 1982ApJ...254..162G
- Keywords:
-
- Angular Momentum;
- K Stars;
- Late Stars;
- Red Giant Stars;
- Stellar Evolution;
- Stellar Rotation;
- Braking;
- Convection;
- Line Spectra;
- Rigid Structures;
- Stellar Envelopes;
- Stellar Magnetic Fields;
- Stellar Models;
- Stellar Spectra;
- Astronomy