Evolutionary Period Changes in Variable Helium-rich White Dwarfs
Abstract
The authors investigate the rates of pulsation period change in realistic, theoretical evolutionary models of pulsating DB white dwarf (DBV) stars and their presumed progenitors, the pulsating PG 1159 (DOV) stars. The expected rates of period change are computed by solving the equations of linear, adiabatic, nonradial oscillation for nonrotating models of hydrogen-deficient white dwarfs. The value of d(ln P)/dt varies over the range (3 - 5)x10-14s-1 for models of DOV stars. Values for DBV stars range from 3x10-16s-1 at Teff = 30,000K to 5x10-17s-1 at Teff = 20,000K. Period changes of this order should be measurable in DBV stars over a few observing seasons. The effects of varying stellar mass and chemical composition on the numerical results are also examined.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1986
- DOI:
- 10.1086/164013
- Bibcode:
- 1986ApJ...302..530K
- Keywords:
-
- Stellar Composition;
- Stellar Evolution;
- Stellar Oscillations;
- Variable Stars;
- White Dwarf Stars;
- Helium;
- Stellar Luminosity;
- Stellar Mass;
- Stellar Models;
- Stellar Temperature;
- Astrophysics;
- STARS: EVOLUTION;
- STARS: INTERIORS;
- STARS: PULSATION;
- STARS: WHITE DWARFS