Scientists find universe's faintest stars

Washington, Dec 11 (ANI): Scientists have found the universe's faintest stars, in the form of a pair of twin "brown dwarfs", each just a millionth as bright as the sun.

These stars have been spotted by a team led by MIT (Massachusetts Institute of Technology) physicist Adam Burgasser.

"These brown dwarfs are the lowest power stellar light bulbs in the sky that we know of," said Burgasser.

According to Burgasser, "In this regime (of faintness), we expect to find the bulk of the brown dwarfs that have formed over the lifetime of the galaxy."

"So, in that sense, these objects are the first of these 'most common' brown dwarfs, which haven't been found yet because they are simply really faint," he added.

"Both of these objects are the first to break the barrier of one millionth the total light-emitting power of the sun," he further added.

Astronomers had thought the pair of dim bulbs was just a single typical, faint brown dwarf with no record-smashing titles.

But, when Burgasser and his team used NASA's Spitzer Space Telescope to observe the brown dwarf in infrared light, it was able to accurately measure the object's extreme faintness and low temperature for the first time.

The Spitzer data revealed that what seemed to be a single brown dwarf is in fact twins.

Brown dwarfs are compact balls of gas floating freely in space, too cool and lightweight to be stars but too warm and massive to be planets.

When Burgasser and his collaborators used Spitzer's ultrasensitive infrared vision to learn more about the object, thought to be a solo brown dwarf, the data revealed a warm atmospheric temperature of 565 to 635 Kelvin (560 to 680 degrees Fahrenheit).

While this is hundreds of degrees hotter than Jupiter, it's still downright cold as far as stars go.

In fact, the brown dwarfs, called 2MASS J09393548-2448279, or 2M 0939 for short, are among the coldest brown dwarfs measured so far.

Spitzer's measurements told the astronomers that both bodies are one million times fainter than the sun in total light, and at least one billion times fainter in visible light alone.

Burgasser said that studying these objects could help astronomers understand details of brown dwarf structure and evolution.

"These observations allow us to see for the first time what the atmospheres of very old and/or very low mass brown dwarfs contain and how they are structured," he said. (ANI)