The influence of the equation of state on the zero-age main sequence and the Sun.
Abstract
In the light of the present uncertainty in the equation of state of stellar interiors, the authors have calculated stellar and solar models using three different formalisms for the equation of state. They have considered (1) a mixture of ideal gases using an artificial pressure-ionization device, (2) an equation of state where pressure ionization is achieved by the confined-atom model, and (3) an equation of state containing a large number of atomic and ionic species, with detailed internal partition functions, containing weighted occupation probabilities. The authors have examined the effect of these equations of state on the position of a star in the H-R diagram: the result is either a displacement of the star on the zero-age main sequence (ZAMS) or, for masses lower than 0.7 Msun a change in the slope of the ZAMS. Furthermore they have carried out the usual calibration procedure in order to obtain the initial He abundance Y of the solar model.
- Publication:
-
Seismology of the Sun and Sun-Like Stars
- Pub Date:
- December 1988
- Bibcode:
- 1988ESASP.286..661L
- Keywords:
-
- Equations Of State;
- Main Sequence Stars;
- Stellar Interiors;
- Stellar Physics;
- Sun;
- Stellar Evolution;
- Stellar Models;
- Stellar Structure;
- Solar Physics;
- Equation of State: Stellar Models;
- Equation of State: Solar Models