On the excitation of PG 1159-type pulsations
Wetterchrüzstr. 8c, 4410 Liestal, Switzerland e-mail: email@example.com
2 Departament de Física Aplicada, Universitat Politècnica de Catalunya, Av. del Canal Olímpic, s/n, , Castelldefels, Barcelona, Spain
3 Astronomical Institute, School of Sciences, Tohoku University, Sendai , Japan
Accepted: 17 April 2005
Stability properties are presented of dipole and quadrupole nonradial oscillation modes of model stars that experienced a late helium shell flash on their way to the white-dwarf cooling domain. The computed instability domains are compared with the observed hot variable central stars of planetary nebulae and the GW Vir pulsators.
Key words: stars: evolution / stars: white dwarfs / stars: oscillations
© ESO, 2005