More brown dwarfs.

Until a year ago, researchers had had little luck finding the failed stars known as brown dwarfs. These dim, difficult-to-detect bodies form as stars do, but their low mass and weak gravity make them too cool to shine by fusion of lightweight elements into heavier ones. New observations suggest that brown dwarfs may be fairly common in the solar neighborhood. Unlike other brown dwarfs detected last year, which reside in clusters or have an orbiting partner, all of the five most recently found bodies sit alone in the sky.

Last month, at the Royal Astronomical Society's National Astronomy Meeting in Liverpool, England, researchers reported that the starlike object 296A, about 100 light-years from Earth, is a probable brown dwarf. While analyzing light emitted by 296A, a team led by Hugh Jones of Liverpool John Moores University found lithium, an element indicative of a brown dwarf (SN: 6/24/95, p. 389).

The team estimates that 296A has 60 times Jupiter's mass, a surface temperature of 2,800 kelvins, and a luminosity one-thousandth that of the sun.

In addition, Jones and Michael R.S. Hawkins of the Royal Observatory of Edinburgh reported that they had detected four much cooler, fainter brown dwarfs. Stacking together more than 100 photographic plates taken by a U.K.

Schmidt telescope near Coonabarabran, Australia, the astronomers spied six red bodies too faint to be seen in a single plate. Four of these objects turned out to reside in the solar neighborhood, indicating that they had a luminosity one-hundred-thousandth that of the sun-far too dim to be stars.

Gibor Basri of the University of California, Berkeley says the extreme faintness of the four objects provides compelling evidence of a brown dwarf pedigree.