Recent Advances in the Theoretical Modeling of Pulsating Low-mass He-core White Dwarfs

L. G. ALTHAUS; S. O. KEPLER; A. H. CÓRSICO; CALCAFERRO, L. M.; A. M. SERENELLI; C. S. JEFFERY

Warwick

Workshop; 20th European White Dwarf Workshop; 2016

University of Warwick

Many extremely low-mass (ELM) white-dwarf (WD) stars are currently beingfound in the field of the Milky Way. Some of these stars exhibitlong-period nonradial g-mode pulsations, and constitute the class of ELMV pulsating WDs. Inaddition, several low-mass pre-WDs, which could be precursors of ELMWDs, have been observed to show short-period photometric variations likely due tononradial p modes and radial modes. They could constitute a new class ofpulsating low-mass pre-WD stars, the pre-ELMV stars. Here, we present the recentresults of a thorough theoretical study of the nonadiabatic pulsationproperties of low-mass He-core WDs and pre-WDs on the basis of fully evolutionarymodels representative of these stars.