Asteroseismological Analysis of Rich Pulsating White Dwarfs

Abstract

We present the results of the asteroseismological analysis of two rich DAVs, G38-29 and R808, recent targets of the Whole Earth Telescope. 20 periods between 413 s and 1089 s were found in G38-29's pulsation spectrum, while R808 is an even richer pulsator, with 24 periods between 404 s and 1144 s. Traditionally, DAVs that have been analyzed asteroseismologically have had fewer than half a dozen modes. Such a large number of modes presents a special challenge to white dwarf asteroseismology, but at the same time has the potential to yield a detailed picture of the interior chemical make-up of DAVs.We explore this possibility by varying the core profiles as well as the layer masses.We use an iterative grid search approach to find best fit models for G38-29 and R808 and comment on some of the intricacies of fine grid searches in white dwarf asteroseismology.