Abstract

Uncertainties in the white dwarf core chemical profiles and their impact on asteroseismology of ZZ Ceti stars

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

Francisco De Gerónimo (Universidad Nacional de La Plata, Argentina), Leandro G. Althaus (Universidad Nacional de La Plata), Alejandro H. Córsico (Universidad Nacional de La Plata), Alejandra D. Romero (UFRGS, Brazil)

We present in this work an estimation of the uncertainties in the C/O chemical profiles of the cores of white dwarf stars, and their impact on ZZ Ceti pulsations. In particular, we focus on the uncertainties resulting from the incomplete knowledge of the 12C(alpha, gamma)16O nuclear reaction rate. Specifically, we have computed about 28 evolutionary sequences of stars with initial masses between 1 to 5 Msun and solar metalicity (XH= 0.725, Z= 0.01), from the ZAMS to the white dwarf phase, by considering the highest and lowest extreme values of the reaction rate provided by Kunz et al. (2002). We asses for the first time the impact that these uncertainties have on the asteroseismological period fits of ZZ Ceti stars.

Mode of presentation: poster