Una nueva región de inestabilidad pulsacional para enanas blancas de baja masa que experimentan flashes de CNO

A. H. CÓRSICO; L. G. ALTHAUS; CALCAFERRO, LEILA M; K. BELL

Córdoba

Congreso; 63 Reunión Anual de la Asociación Argentina de Astronomía; 2021

Universidad Nacional de Córdoba - Observatorio de Córdoba

While evolving toward their terminal white-dwarf cooling branches, some low-mass helium (He)-core white-dwarf stellar models experience nuclear flashes. Prior to the occurrence of each flash, global pulsations may be driven by stable hydrogen burning, allowing the study of the internal structure of these stars through asteroseismology. We perform a pulsational stability analysis considering the effects of the ɛ mechanism in destabilizing gravity-mode periods for sequences of low-mass He-core stars on their early white-dwarf cooling branches going through CNO flashes. We estimate the ranges of unstable periods and the instability domain in the log(g) - Teff plane.