The Whole Earth Telescope as an Instrument

Abstract

High resolution power spectroscopy of rapid variable stars, the product of the Whole Earth Telescope observing network, has provided many observational surprises with which we can confront our current theories of stellar pulsation and evolution. We find that variable white dwarfs display significant changes on timescales of days, months and years, in addition to the rapid pulsations described by pulsation theory and the slow, secular drifts in period expected from the cooling process. These and other surprises convince us the network is a valuable research instrument, and its strengths and weaknesses are summarized in this context.