Brown Dwarf with Arctic Temperatures, the Coldest Ever Found, Spied by NASA Telescopes
Astronomers have spotted a relatively nearby star-like object known as a brown dwarf that is uncharacteristically cool. In fact, it has Arctic temperatures, making it the coldest brown dwarf known to exist.
Brown dwarfs are dim, star-like bodies. They are born like stars, as a collapsing ball of gas, but they lack the mass to burn nuclear fuel and radiate starlight.
The newfound brown dwarf is only 7.2 light years away from Earth, slightly farther than the closest star system to the Sun, Alpha Centauri, which is about 4 light years away.
Astronomers found the coldest brown dwarf using NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescope. They've named the object, which has temperatures similar to Earth's North Pole, WISE J085510.83-071442.5.
The temperature on this cool brown dwarf is between minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius). The previous record-holder for coolest brown dwarf was much warmer, at about room temperature.
"It's very exciting to discover a new neighbor of our solar system that is so close," said Kevin Luhman, an astronomer at Pennsylvania State University's Center for Exoplanets and Habitable Worlds, University Park. "And given its extreme temperature, it should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures."
Cool objects like brown dwarfs can appear to be invisible when viewed through a visible-light telescope. But infrared imaging can usually detect them. When studying multiple images of a field of space, objects that are closer to Earth will appear to move the most against the background.
"This object appeared to move really fast in the WISE data," Luhman said in a NASA statement. "That told us it was something special."
The chilly brown dwarf was first spotted in March 2013, and further analysis of it revealed details bout its temperature, location and more.
"It is remarkable that even after many decades of studying the sky, we still do not have a complete inventory of the sun's nearest neighbors," said Michael Werner, the project scientist for Spitzer at NASA's Jet Propulsion Laboratory in Pasadena, Calif. JPL manages and operates Spitzer. "This exciting new result demonstrates the power of exploring the universe using new tools, such as the infrared eyes of WISE and Spitzer."