1. Evolution and asteroseismology of ultra-massive DA white dwarfs
- Author
-
F. C. De Gerónimo, A. H. Córsico, Leandro Gabriel Althaus, and M. E. Camisassa
- Subjects
Physics ,010308 nuclear & particles physics ,Space and Planetary Science ,0103 physical sciences ,White dwarf ,Astronomy ,Astronomy and Astrophysics ,010303 astronomy & astrophysics ,01 natural sciences ,Asteroseismology - Abstract
Ultra-massive (⩾M⊙) oxygen/neon (ONe) core white dwarfs (WDs) are the result of the evolution of isolated progenitor stars with masses above 6−M⊙. It is expected that hydrogen-rich (DA) ultra-massive WDs harbor crystallized cores at the typical temperatures of the ZZ Ceti instability strip. These stars offer a unique opportunity to study the processes of crystallization and to infer their core chemical composition. We present a study of the evolution and asteroseismology of ultra-massive DA WDs. We found that all pulsating WDs known to date with M⩾1.1M⊙ should have more than 80% of their mass crystallized, if a ONe-core is assumed. Finally, we present a complete asteroseismological analysis to the well known ZZ Ceti BPM 37093 and a preliminary analysis to GD 518 and SDSS J0840+5222.
- Published
- 2019