James W. Liebert

KUV 05134 + 2605 - A new pulsating DB white dwarf

Time-series photometry is reported that shows that KUV 05134 + 2605 is a pulsating DB white dwarf. The light curve shows sharply peaked pulses with a complicated mode structure including periods between 350 and 900 sec. The optical spectrum appears to be that of a star near the hot end of the DB sequence, consistent with theoretical predictions and the temperature range estimated empirically for previously known DBV stars. 21 refs.

Spectrophotometry of Hot White Dwarfs from the Palomar-Green Survey

The Palomar-Green Survey (1977) contains a list of some 3000 spectroscopically classified stellar objects, chosen on the basis of ultraviolet excess. The survey covers 10,000 square degrees of the sky above |b|=30° with δ≥10° down to an average limiting B=16.2. A significant subset of this sample is a new catalogue of over 700 newly discovered hot degenerates (Green 1979). The combination of selection by color only without regard to motion and the large area covered resulted in the discovery of some rare, luminous degenerates and pre-degenerate objects. We report here on the first observations in a program of more detailed spectroscopic study of these objects, and display representative groups of common spectral or physical properties. These scans at 1.5-2.5 A resolution were obtained with either the KPNO 2.1-m and intensified image dissector scanner or the Palomar 1.5-m with SIT spectrograph.