Cepheid masses from observations and pulsation theory.
Abstract
Cepheid masses are calculated using radii measured recently by the Baade-Wesselink and Barnes et al. methods. They are compared to masses which use only the well-observed fundamental mode period, Pi0, and an approximate effective surface temperature, Te. It is found that pulsation masses using observed Pi0, L, and colors (to give mean Te) now agree much better with evolutionary and theoretical masses but that the Baade-Wesselink and Barnes et al. radii imply lower average masses for 69 cases. This discrepancy can be alleviated and the agreement of evolution, theoretical, and pulsation masses not destroyed by using recently proposed helium-rich surface layers in theoretical Cepheid masses which increase the pulsation constant as well as the bump, beat, and the Wesselink and Barnes et al. radius masses.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1979
- DOI:
- 10.1086/156947
- Bibcode:
- 1979ApJ...229..212C
- Keywords:
-
- Cepheid Variables;
- Pulsars;
- Stellar Mass;
- Computer Programs;
- Dimensional Measurement;
- Helium;
- Mass Distribution;
- Mass Ratios;
- Mass Transfer;
- Radii;
- Stellar Luminosity;
- Temperature Effects;
- Astrophysics;
- Cepheids:Diameters;
- Cepheids:Masses;
- Cepheids:Models;
- Cepheids:Periods