Nonradial Oscillations of White Dwarfs, Hot White Dwarfs, and 10 M_{sun} Models
Abstract
Solutions to the Pekeris equation for nonradial oscillations have been obtained for white dwarfs, hot white dwarfs, and 10 I models. Solutions for polytropic models are presented for comparison with previous calculations. Two astronomical applications of the present calculations are considered. The first is concerned with the conditions necessary for excitation of nonradial oscillations in white dwarfs and hot white dwarfs that are unstable to radial pulsation. The second application is concerned with the occurrence of double periodicity that is observed for a number of p variables. The calculations indicate that when 10 Al0 modeis have evolved to about 1 mag above the main sequence, their pulsation periods are comparable to those of p CMa variables. In addition, the fundamental radial mode and the t = 2 Kelvin mode are still nearly in resonance. The calculations support the suggestion of Chandrasekhar and Lebovitz that the observed double periodicity is due to a near degeneracy between these modes.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1970
- DOI:
- 10.1086/150727
- Bibcode:
- 1970ApJ...162..963H