Asteroseismological modeling of PG 1159-035, the prototype of the GW Vir variable stars

A. H. C\'ORSICO, L. G.ALTHAUS, M. M. MILLER BERTOLAMI, S. O. KEPLER YJ. E. S. COSTA

Tuebingen, Alemania

Conferencia; HYDROGEN DEFICIENT STARS; 2007

Institute for Astronomy and Astrophysics at the University of Tübingen, Germany.

We present a comprehensive asteroseismological study on PG 1159$-$035,the prototype of the GW Vir  variable stars, performed on the basis offull  PG1159 evolutionary  models  with stellar  masses  in the  range$0.530 - 0.741 M_{\odot}$.  We  infer the stellar mass of PG1159$-$035from  the period  spacing data.  We  also derive,  on the  basis of  aperiod-fit procedure,  an asteroseismological model  representative ofPG1159$-$035  which reproduces  the  observed period  pattern with  anaverage of the period differences  of $0.62-1.02$ s.  The model has aneffective  temperature  of  $128\,  000$  K,  a  stellar  mass  $0.565M_{\odot}$, a surface  gravity $\log g= 7.42$, and  a He-rich envelopethickness of $M_{\rm env}= 0.017 M_{\odot}$.