Space Telescope Science
Astronomers have made the first unambiguous detection of an elusive type of object known as a brown dwarf.
The evidence consists of observations from 60-inch and 200-inch telescopes on Mount Palomar, and a confirmatory image from the Hubble telescope. The brown dwarf, called Gliese 229B (GL229B), is a small companion to the cool, red star Gliese 229, located 19 light-years from Earth in the constellation Lepus. Estimated to be 20 to 50 times the mass of Jupiter, GL229B is too massive and hot to be classified as a planet, but too small and cool to shine like a star. At least 100,000 times dimmer than Earth's Sun, the brown dwarf is the faintest object ever seen orbiting another star.