Nonlinear effects in time-resolved spectra of DAVs
Institut für Theoretische Physik und Astrophysik, Universität Kiel, 24098 Kiel, Germany e-mail: email@example.com
Corresponding author: J. Ising, firstname.lastname@example.org
Accepted: 2 April 2001
Numerical simulations of light curves of variable DA white dwarfs (ZZ Ceti stars) predict flux amplitudes with surface distributions different from the spherical harmonics of the pulsation mode in deeper layers. In contrast to the results of the perturbation analysis by Gold reich and Wu, this is also true for the fundamental period of the flux variation. As a consequence, normalized amplitude spectra depend not only on the mode number l but also on pulsation amplitude and inclination. Another new result is that with increasing amplitude of the pressure variation below the convection zone, the flux variation at the surface goes through a maximum and then decreases again.
Key words: stars: white dwarfs / stars: atmospheres / stars: interiors / convection / stars: variable: general
© ESO, 2001