Science press release --------------------- Cataclysmic Cannibals in the Sky Embargoed: Not for Release Until 2:00 pm U.S. ET Thursday, 07 December 2006 Astronomers found a binary star class that had been predicted, but not yet seen. Called cataclysmic variables, these flickering binary star systems contain a compact white dwarf that sucks material from its larger companion star, eventually causing the white dwarf to cease hydrogen burning and becomes a brown dwarf. Theory held that most short period systems should have already evolved to brown dwarfs. Stuart Paul Littlefair and colleagues accurately timed the eclipses in a short period cataclysmic variable system and showed that the donor is a brown dwarf 5 percent of the Sun\uffffs mass. Because the star\uffffs mass is higher than its orbital period would suggest, the brown dwarf radii may be underestimated by current evolutionary models. Pierre F. L. Maxted discusses this in a related Perspective. This research appears in the 08 December 2006 issue of the journal Science. Caption for image Artist's impression of SDSS 1035+0551. The hot white dwarf is the same size as the Earth, yet weighs the same as our Sun. The brown dwarf is about the same size as Jupiter, but much more massive. The gravity of the white dwarf pulls gas from the brown dwarf; this gas spirals down onto the surface of the white dwarf, like water down a plughole, forming an "accretion disc" of hot gas around the white dwarf. Where the falling gas from the brown dwarf hits the accretion disc, it creates a hot spot. The position of this hot spot depends on the masses of the two stars. The authors precisely timed when the white dwarf and hot spot were eclipsed by the brown dwarf. This allowed them to measure the location of the hot spot, and infer the masses of the two stars.