Hot Degenerates in the MCT Survey. I. MCT 0130-1937, a New, Color-selected PG 1159 Object
Kepler, S. O.; Fontaine, G.; Wesemael, F.; Holberg, J. B.; Irwin, M. J.; Lamontagne, R.; Demers, S.
Chile, Canada, United Kingdom
Abstract
In the course of a survey for high-latitude, UV excess objects in the Southern Hemisphere, a new white dwarf star belonging to the PG 1159 spectroscopic class was discovered. A variety of spectroscopic observations show this object to be similar to the prototype PG 1159 - 035 in exhibiting He II, C IV, and O VI features in its optical spectrum, as well as a rich absorption spectrum in the ultraviolet. In addition, the slope of its energy distribution appears as steep as that of PG 1159 - 035 and is consistent with the Rayleigh-Jeans tail of a very hot star. White-light, high-speed photometry reveals that this object does not exhibit periodic variations in the range 10-2000 s with semiamplitudes larger than about 0.002 mag. The importance of such objects for current models of the spectral evolution of white dwarfs is emphasized.