Abstract

Theoretical modeling of pulsating low-mass white dwarfs

Alejandro H. Córsico (Universidad Nacional de La Plata, Argentina)

Alejandro H. Córsico (Universidad Nacional de La Plata), Leandro G. Althaus (Universidad Nacional de La Plata)

Many low-mass white dwarfs with masses below 0.45 Msun, including the so called extremely low-mass white dwarfs (ELM, M < 0.18-0.20 Msun), have recently been discovered in the field of our Galaxy through dedicated photometric surveys. The subsequent discovery of long-period g-mode pulsations in some of them (five up to now) has opened the unprecedented chance of probing the internal structure of these stars. In particular, one of the objects exhibits short-period pulsations that could be due to p-modes or even to radial modes. If this were true, this would be the first time that p-modes/radial modes are detected in a pulsating white dwarf star. We present here the results of a detailed adiabatic radial and nonradial pulsational study based on new evolutionary sequences of low-mass He-core white dwarfs derived from the binary star evolution computations of Althaus et al. (2013). The main aim of this study is to provide a theoretical basis from which to interpret present and future observations of variable low-mass white dwarfs.

Mode of presentation: poster