December 11, 2008

Universe’s dimmest known objects are found

U.S. space agency officials say the Spitzer Space Telescope has discovered the dimmest known star-like objects in the universe.

The record goes to twin brown dwarfs, or failed stars, each of which shines with only one-millionth the light of our sun, the National Aeronautics and Space Administration said.

Astronomers previously thought the faint image was that of just one brown dwarf. But when the Spitzer Space Telescope observed the object in infrared mode, it measured the extreme faintness and low temperature for the first time. That data revealed the brown dwarf was, in fact, twins.

Both of these objects are the first to break the barrier of one-millionth the total light-emitting power of the sun, said Adam Burgasser of the Massachusetts Institute of Technology.

Brown dwarfs are compact balls of gas floating freely in space, but they are too cool and lightweight to be stars, yet too warm and massive to be planets, NASA said. The newly identified brown dwarfs are located about 17 light-years from Earth, toward the constellation Antlia.

The Spitzer Space Telescope is managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif. The discovery is reported in the Astrophysical Journal Letters.