Opisthodromism on the horizontal branch?
Abstract
The standard model of the horizontal branch (HB) has assumed that on the average stars lose about 25% of their mass on the first ascent of the RGB and that some parameter varies from star to star, leading to roughly a 105 dispersion in this mean mass loss. The authors here review the current status of HB modeling in view of the vast array of observed high precision color - magnitude diagrams of globular clusters. There have been many improvements in the input physics, but the major uncertainty confronting the models - mass loss - remains. We still have only a dimensional parameterization of mass loss, and the parameter leading to dispersion from star to star has never been identified. HBs show a distressing diversity which defy simple classification schemes. The authors speculate on how observed pathological HB morphology may be used to study mass loss.
- Publication:
-
Stellar Ecology: Advances in Stellar Evolution,
- Pub Date:
- 1997
- Bibcode:
- 1997seas.conf...74R
- Keywords:
-
- Horizontal-Branch Stars: Globular Clusters;
- Horizontal-Branch Stars: Stellar Evolution;
- Horizontal-Branch Stars: Mass Loss