Non-LTE analysis of four PG1159 stars.
Abstract
A spectral analysis of four members of the PG1159 class is performed. These stars are believed to be very hot pre-White Dwarf stars. It is shown that the photospheres of PG1159 stars are dominated by helium and carbon and that a significant amount of oxygen is present. It is also found that the nonradial pulsations observed in some PG1159 stars are driven by the cyclic ionization of carbon and oxygen.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 1991
- Bibcode:
- 1991A&A...244..437W
- Keywords:
-
- Nonequilibrium Thermodynamics;
- Photosphere;
- Spectrum Analysis;
- Stellar Atmospheres;
- White Dwarf Stars;
- Carbon;
- Helium;
- Hot Stars;
- Oxygen;
- Radiative Transfer;
- Stellar Composition;
- Astrophysics