Brown Dwarf Gliese 229B.

The spot near the bottom is an image of an unusual type of object: a brown dwarf . A brown dwarf is sometimes called a “failed star” because it does not have enough mass to shine by nuclear fusion . A brown dwarf is more massive than a planet , though, and thought to have formed through stellar-like nebular condensation . Brown dwarfs and planets are likely quite abundant, but usually difficult to see in the glare of brighter stars they orbit. New techniques , such as using coronagraphic masks to block the light of the bright star, are allowing the detection of these faint stellar companions. Above , much of the bright light of central Gliese 229A has been blocked and digitally subtracted, leaving the clearest image yet of Gliese 229B . Perfecting techniques like this increases ability to detect still dimmer Earth-type planets orbiting nearby stars .