Time Series Observations of the Mysterious Carbon Atmosphere White Dwarfs


Kurtis A. Williams

Publication Title

GALEX Proposal id.67

Document Type



Carbon-atmosphere (spectral type DQ) white dwarfs are a recently-recognized class of star that may be the final remnant of the most massive stars to form white dwarfs. We have discovered that a subset of these white dwarfs are variable. We suspect that these DQVs are typical pulsating white dwarfs, and therefore would be excellent asteroseismological probes of the dividing line between white dwarfs and supernovae. Yet the optical variations of DQVs are odd, and leave open the possibility that we are not seeing pulsations, but perhaps are seeing a new and potentially interesting type of cataclysmic variable. We propose to obtain long time-series GALEX imaging of two DQVs. Our primary goals are to compare the UV and optical properties of the light curves in order to differentiate between the pulsational interpretation of the light variations and the interacting binary interpretation. If the variations are found to be due to standard white dwarf pulsations, then the full arsenal of white dwarf asteroseismology can be brought to bear on these interesting but mysterious stars.


Physics and Astronomy



This document is currently not available here.