Nonradial oscillations of slowly rotating white dwarfs.
Abstract
Effects of rotation on frequencies of gmode oscillations in whitedwarf models are examined by using smallperturbation theory. The secondorder term in the angular velocity of rotation is included in the analysis. It is shown that this secondorder term distorts the equidistant distribution of the split eigenfrequencies associated with the firstorder effect. Eigenvalues of the five lowest gmodes for l = 1, 2, and 3 are calculated numerically for three 0.6solar mass models. The results obtained imply a slowly rotating star with an equatorial velocity of about 10 km/s oscillating in l = 2 or 3 and k = 3 to 30. Wolff's (1977) interpretation that some of the multiperiodic light curves of ZZ Cetitype whitedwarf variables might arise from rotation of nonlinearly coupled gmodes is criticized on the grounds that it implies very high rotational velocities. The power spectra of five ZZ Cetitype variables are discussed in terms of rotational splitting.
 Publication:

Acta Astronomica
 Pub Date:
 1978
 Bibcode:
 1978AcA....28..441C
 Keywords:

 Perturbation Theory;
 Stellar Rotation;
 Variable Stars;
 White Dwarf Stars;
 Angular Velocity;
 Eigenvalues;
 Frequency Distribution;
 Light Curve;
 Oscillations;
 Power Spectra;
 Splitting;
 Stellar Mass;
 Stellar Models;
 Astrophysics