Hot DB White Dwarfs from the Sloan Digital Sky Survey


Eisenstein DJ, Liebert J, Koester D, Kleinmann SJ, Nitta A, Smith PS, Barentine JC, Brewington HJ, Brinkmann J, Harvanek M, et al. Hot DB White Dwarfs from the Sloan Digital Sky Survey. The Astronomical Journal. 2006;132 :676-691.

Date Published:

August 1, 2006


We present ugriz photometry and optical spectroscopy for 28 DB and DOwhite dwarfs with temperatures between 28,000 and 45,000 K. About 10 ofthese are particularly well observed; the remainder are candidates.These are the hottest DB stars yet found, and they populate the ``DBgap'' between the hotter DO stars and the familiar DB stars cooler than30,000 K. Nevertheless, after carefully matching the survey volumes wefind that the ratio of DA stars to DB stars is a factor of 2.5 larger at30,000 than at 20,000 K, suggesting that the ``DB gap'' is indeeddeficient and that some kind of atmospheric transformation takes place