Evolution of Very Low Mass Stars and Brown Dwarfs. II. The Population II
Abstract
This paper addresses a number of problems connected with the evolution of low-mass (M ≤ 0.8 M_sun;) and very low mass (M ≥ 0.07 M_sun;) stars having metal contents much smaller than the solar metal content. Two main chemical compositions bracketing the Population II regime are considered: helium and metal contents Y = 0.23, Z = 10-4 (Cox and Stewart opacities) and Y = 0.25, Z = 10-3 (Alexander, Johnson, and Rypma opacities). For these compositions, the hydrogen burning minimum mass is evaluated. It is confirmed that the atmospheric opacities are the main factor influencing the minimum main-sequence luminosity. Population II luminosity functions (LFs) are constructed and applied to the interpretation of globular cluster main-sequence LFs.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1987
- DOI:
- 10.1086/165582
- Bibcode:
- 1987ApJ...320..653D
- Keywords:
-
- Brown Dwarf Stars;
- Globular Clusters;
- Opacity;
- Stellar Evolution;
- Stellar Luminosity;
- Stellar Mass;
- Main Sequence Stars;
- Mass To Light Ratios;
- Astrophysics;
- CLUSTERS: GLOBULAR;
- LUMINOSITY FUNCTION;
- OPACITIES;
- STARS: EVOLUTION;
- STARS: INTERIORS;
- STARS: POPULATION II