| Issue |
EAS Publications Series
Volume 63, 2013
New Advances in Stellar Physics: From Microscopic to Macroscopic Processes
|
|
|---|---|---|
| Page(s) | 297 - 302 | |
| Section | Hydrodynamics, Mixing Processes and Transport of Angular Momentum in Stars | |
| DOI | https://doi.org/10.1051/eas/1363033 | |
| Published online | 19 December 2013 | |
G. Alecian, Y. Lebreton, O. Richard and G. Vauclair (eds)
EAS Publications Series, 63 (2013) 297–302
Accretion of planetary matter from debris disks around white dwarfs: the fate of planetary systems
1 Université de Toulouse, UPS-OMP, IRAP, France
2 CNRS, IRAP, 14 avenue Edouard Belin, 31400 Toulouse, France
3 Facultad de Ciencias Astronomicas y Geosicas, 20646 La plata, Argentina
4 Instituto de Astrosica de La Plata, 20646 La plata, Argentina
e-mail: morgan.deal@irap.omp.eu
e-mail: sebastien.deheuveuls@irap.omp.eu
e-mail: gerard.vauclair@irap.omp.eu
e-mail: sylvie.vauclair@irap.omp.eu
e-mail: fwachlin@gmail.com
Heavy elements are observed in the atmospheres of many DA and DB white dwarfs, and their presence is attributed to the accretion of matter coming from debris disks. Several authors have deduced accretion rates from the observed abundances, taking into account the mixing induced by the convective zones and the gravitational settling. The obtained values are different for DA and DB white dwarfs. Here we show that an important process was forgotten in all these computations: thermohaline mixing, induced by the inverse μ-gradient built during the accretion process. Taking this mixing into account leads to an increase of the derived accretion rates, specially for DA white dwarfs, and modifies the conclusions.
© EAS, EDP Sciences, 2013