Evolutionary sequences for red giant stars.
Abstract
An extensive grid of 46 red-giant sequences is computed in a self-consistent manner for stars evolving from the subgiant branch to the onset of core helium burning. The sequences cover values of Y from 0.10 to 0.40, Z from 0.00001 to 0.4, and total mass (M) from 0.70 to 2.20 solar masses. Effects of varying the rate of neutrino emission from zero to twice the usually adopted value are taken into account. The results obtained show that: (1) the red-giant branch shifts to higher effective temperatures with increases in Y or M or decreases in Z; (2) the luminosity at the onset of helium-core flash is reduced by increases in Y or decreases in Z; (3) the critical mass for the flash is lowered by increases in Y or decreases in Z; (4) an increase in Y, Z, or M reduces the core mass at the onset of the flash; (5) core mass and luminosity decrease when neutrino emission is neglected, while the additional neutrino emission that could result from neutral-current interactions increases the core mass by 0.007 solar mass; and (6) the location at which the flash begins within the degenerate core shifts outward in mass with decreases in Y or M or increases in the rate of neutrino emission.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- March 1978
- DOI:
- 10.1086/190506
- Bibcode:
- 1978ApJS...36..405S
- Keywords:
-
- Red Giant Stars;
- Stellar Evolution;
- Stellar Structure;
- Neutrinos;
- Stellar Luminosity;
- Stellar Mass;
- Stellar Models;
- Stellar Temperature;
- Tables (Data);
- Astrophysics;
- Evolution:Red Giants