Eleven New DA White Dwarf Variable Stars from the Sloan Digital Sky Survey

Abstract

We report the discovery of 11 new variable DA white dwarf (ZZ Ceti) stars. Candidates were selected by deriving temperatures from model fits to spectra obtained from the Sloan Digital Sky Survey (SDSS). We also find objects whose temperatures and gravities indicate they lie within the instability strip for pulsation but were not observed to vary. Although the temperatures are based on relatively low signal-to-noise ratio spectra, an impure strip is unexpected, which if confirmed, has implications for DA asteroseismology. This work brings the total number of published variable DA white dwarf stars to 82.