December 11, 2008—The faintest starlike objects in the universe (shown in an artist's rendering) have emerged from the shadows, a new study shows.
A pair of brown dwarfs—each about a millionth as bright as the sun—were discovered by NASA's Spitzer Space Telescope.
"These brown dwarfs are the lowest power stellar light bulbs in the sky that we know of," study leader Adam Burgasser, a physicist at the Massachusetts Institute of Technology, said in a statement.
Previously, astronomers had thought the dim bodies were a single, run-of-the-mill brown dwarf—a compact ball of gas floating in space that is neither planet nor star.
But Burgasser and his team revealed that the object—which was twice as bright as it should have been given its temperature—was instead extremely faint twins.
Scientists expect to find many more dim brown dwarfs using Spitzer's ultrasensitive infrared technology. They hope the discoveries will show how brown dwarfs evolve.
The observations "allow us to see for the first time what the atmospheres of very old or very low mass brown dwarfs contain and how they are structured," Burgasser said.
The study appeared December 10 in Astrophysical Journal Letters.