The Gravity Oscillations of White Dwarfs

Abstract

The second order differential equations governing the non-radial adiabatic oscillations of stars have been solved for a variety of white dwarf models. It is found that the inclusion of convection in the envelopes of the models with surface temperatures corresponding to those of HL Tau 76 and G44–32 does not alter the eigenvalues significantly and the periods of the lowest order modes are shorter than the observed periods by a factor of about 2. The eigenfunctions of hot white dwarf models which include a hydrogen burning shell in equilibrium show that the oscillations have a large amplitude only in the hydrogen envelope. The relevance of these results to the observation of periodic variations in cataclysmic variables is discussed.