El efecto de la difusión del Ne en las propiedades evolutivas y pulsacionales de las enanas blancas

CAMISASSA, M. E.; M. M. MILLER BERTOLAMI; L. ALTHAUS; CORSICO, A.

La Plata

Workshop; 58ava Reunion Anual de la Asociacion Argentina de Astronomia; 2015

Due the large neutron excess of Ne, this isotope rapidly sediments in the interior of the white dwarfs. This process releases an extra amount of energy, thus delaying the cooling times of the white dwarf. Furthermore, the overabundance of Ne in the inner regions of the star, modifies the Brunt-Vaisala frequency, thus, altering its pulsational properties. In this work, we discuss the impact of Ne sedimentation in white dwarfs derived from solar metallicity progenitors (). We performed evolutionary calculations of white dwarfs of, , and . These models are the result of the full evolutionary calculations of their progenitor stars, starting at the zero age main sequence. Our computations show that Ne sedimentation delays the cooling times of white dwarfs in about 1 Gyr at low luminosities (), affecting the techniques that use white dwarfs to date stellar populations. Neglecting Ne sedimentation when calculating the theoretical white dwarf luminosity function, implies to underestimate the age of the stellar population. Additionally, we studied the consequences of Ne sedimentation on the pulsational properties of ZZ Ceti white dwarfs.