IALP   13078
INSTITUTO DE ASTROFISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Asteroseismic inferences on GW Virginis variable stars in the frame of new PG 1159 evolutionary models
Autor/es:
CORSICO, A. H.; ALTHAUS, L. G.
Revista:
ASTRONOMY AND ASTROPHYSICS
Editorial:
EDP Sciences
Referencias:
Año: 2006 vol. 454 p. 863 - 881
ISSN:
0004-6361
Resumen:
An adiabatic, nonradial pulsation study  of GW Vir starsis presented.   The pulsation  calculations are based on PG1159 evolutionary sequences with different stellar masses artificially derived from a full evolutionary sequence of 0.5895 Msun that has been computed taking into account the evolutionary history of the progenitor star. The artificial sequences were constructed by appropriately  scaling the stellar mass of the 0.5895 Msun sequence well  before the models reach the low-luminosity, high-gravity stage of the GW Vir domain. We compute  g-mode pulsation  periods  appropriate to  GW Vir  variable stars.  The  implications for the  mode-trapping properties of  our PG 1159 models are  discussed at length. We found  that the mode-trapping features characterizing  our PG  1159 models are  mostly fixed  by the stepped shape  of the core  chemical profile left by  prior convective overshooting.  This  is particularly  true at least  for the  range of periods observed in  GW Vir stars. In addition,  we make asteroseismic inferences  about  the internal  structure  of  the  GW Vir  stars  PG 1159-035, PG 2131+066, PG 1707+427 and PG 0122+200.