On Some Observational Consequences of Nonlinearities in Stellar Pulsations
Abstract
Numerical experiments, which take into account a resonant coupling due to rotation, provide synthetic power spectra for triplets of the l=1 modes split by rotation for two variable white dwarfs, GD 358 and G 29-38 and a beta Cephei star DD Lac. The coupling coefficients are unknown and are set arbitrarily. Nevertheless, the results show that conditions are easily met in white dwarfs for the existence of various types of temporal behavior similar to those observed. Triplets with constant amplitudes and nonlinearly forced equal splits can exist next to triplets with time dependent amplitudes and frequencies. It is found that mode trapping, through its effect on growth rates, can influence finite amplitude behavior. For the fast rotating star DD Lac, it is more difficult to obtain nonlinear equal splits, which may indicate that its resonant coupling coefficients are less nonadiabatic than in the case of white dwarfs.
- Publication:
-
Baltic Astronomy
- Pub Date:
- March 1998
- DOI:
- 10.1515/astro-1998-0108
- Bibcode:
- 1998BaltA...7...21G
- Keywords:
-
- STARS: WHITE DWARFS;
- BETA CEPHEI STARS;
- OSCILLATIONS;
- INDIVIDUAL: G 29-38;
- GD 358;
- DD LAC