Asteroseismology of White Dwarf Stars with the Whole Earth Telescope

Abstract

The Whole Earth Telescope (WET) project is a coöperative effort to obtain global time-series photometry of compact variable stars. The aim of WET is to obtain essentially continuous light curves, from which we compute high-resolution, high signal-to-noise power-spectra. These enable us to apply the powerful theoretical machinery of asteroseismology to determine many of the fundamental parameters of white dwarf stars: rotation rates, magnetic field strengths, total mass, compositional stratification of the envelope, core composition, and more.

The purpose of this review is to provide a brief update on the WET project. I present a list of principle targets for which extensive data sets currently exist, or are planned (as of May 1991). All of the data on each target is in the public domain 18 months after a run, and possibly earlier (at the discretion of the principle investigator for the specific target). I discuss the results for the DOV star PG 1159035 as a case study, emphasizing the science that has just begun to come pouring out, and finally attempt to chart some of the future directions we can expect the WET project to take.