Time-dependent convection study of the driving mechanism in the DBV white dwarfs

Marc-Antoine Dupret (1) , Pierre-Olivier Quirion (2) , G. Fontaine (3) , P. Brassard (3) , A. Grigahcène (4)

1 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
2 Institute for Physics and Astronomy, University of Århus
3 Département de Physique, Université de Montréal
4 CRAAG - Centre de Recherche en Astronomie Astrophysique et Géophysique - Observatoire d'Alger

We apply for the first time time-dependent convection (TDC) models to the study of the driving mechanism of the Pulsating DB (V777 Herculis) white dwarfs. From the blue to the red edge of the instability strip of these stars, TDC appears to play a central role in the driving. Around the blue edge, the convection adapts quasi-instantaneously to the oscillations, so that TDC must be included in the models. For the first time, we show that the red edge of the DB instability strip is successfully obtained with a TDC treatment, especially thanks to the terms due to the turbulent pressure variations, while it is not reproduced with frozen convection models.

Domaines: Astrophysique [astro-ph]

Marc-Antoine Dupret, Pierre-Olivier Quirion, G. Fontaine, P. Brassard, A. Grigahcène. Time-dependent convection study of the driving mechanism in the DBV white dwarfs. Proceedings Of The Second HELAS International Conference: Helioseismology, Asteroseismology And MHD Connections, Aug 2007, Göttingen, Germany, Germany. pp.2051, ⟨10.1088/1742-6596/118/1/012051⟩. ⟨hal-03744071⟩