New evolutionary models for variable sdB stars: the role of extra-mixing

ROMERO, A. D.; CÓRSICO, A. H.; ALTHAUS, L. G.

Córdoba, Argentina

Jornada; Primeras Jornadas sobre Astrofisica Estelar; 2008

Asociación Argentina de Astronomía

We present an evolutionary and pulsational study of subdwarf B (sdB) stars. Specifically, we explore the effects that core overshooting episodes have on the evolution during the Horizontal Branch phase and on the pulsation properties of variable sdB stars. We computed two sets of evolutionary sequences with different masses on the Extreme Horizontal Branch (EHB): one of them taking into account core overshooting and the other one neglecting core overshooting at all. The, we carried out a detailed oulsational analysis of our representative models of sdB stars. In particular, we assessed the effects of the shape of the internal chemical profile on the pulsation characteristic frequencies and on the radial and nonradial adiabatic pulsation spectrum.