Asteroseismological Analysis of Rich Pulsating White Dwarfs

TL;DR

This paper conducts a detailed asteroseismological analysis of two rich pulsating white dwarfs, G38-29 and R808, using numerous observed pulsation modes to infer their internal structures.

Contribution

It introduces a method to analyze white dwarfs with many pulsation modes, enhancing the understanding of their internal chemical profiles.

Findings

Identified 20 and 24 pulsation modes in G38-29 and R808, respectively.

Demonstrated the feasibility of detailed interior modeling with numerous modes.

Discussed challenges and solutions in fine grid searches for white dwarf models.

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.