Grids of evolutionary models from 0.85 to 120M : observational tests and the mass limits.
Abstract
Grids of evolutionary models in the 0.85 to 120 solar mass range with composition X = 0.70, Z = 0.02 are computed with mass loss and moderate core overshooting for the main observable phases of stellar evolution. Detailed tests of observable features sensitive to core overshooting are made in order to better determine, by comparison with standard models, the amount of core overshooting. The test results clearly point in favor of moderate overshooting from convective cores. The consequence of moderate overshooting on several stellar mass limits are analyzed and found to be substantial but not drastic. The minimum initial mass for off-center C-ignition proceeding to central exhaustion is lowered from 9 solar masses to about 6.6 solar masses. The lower mass for the second-dredge-up is brought from 4.6 solar masses to 3.3 solar masses. The maximum mass for degenerate He-ignition becomes 1.85 solar mass rather than 2.2 solar masses.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- February 1989
- Bibcode:
- 1989A&A...210..155M
- Keywords:
-
- Computational Astrophysics;
- Stellar Evolution;
- Stellar Mass;
- Stellar Models;
- Abundance;
- Hertzsprung-Russell Diagram;
- Mass To Light Ratios;
- Stellar Magnitude;
- Stellar Structure;
- Astrophysics