Nonlinear mode coupling in oscillating stars. II - Limiting amplitude effect of the parametric resonance in main sequence stars.
Abstract
The authors study effects of the parametric resonance on the development of acoustic mode instability in a model of ZAMS δ Scuti star. There is a large number of gravity-mode pairs that may be excited already at very low amplitudes of the acoustic mode in a consequence of the parametric instability. A probability distribution of the minimum amplitude at the onset of this instability (critical amplitude) is determined for all acoustic modes with l ≤ 2 that are linearly driven due to κ-mechanism. For none of these modes the mean critical amplitude exceeds 0.02 mag. Equilibrium states involving three coupled modes with constant amplitudes are studied.
- Publication:
-
Acta Astronomica
- Pub Date:
- 1985
- Bibcode:
- 1985AcA....35....5D
- Keywords:
-
- Coupled Modes;
- Main Sequence Stars;
- Stellar Oscillations;
- Variable Stars;
- Vibration Mode;
- Acoustic Instability;
- Amplitudes;
- Nonlinearity;
- Stellar Luminosity;
- Stellar Models;
- Astrophysics