A "brown dwarf" star that appears to be the coldest of its kind—as frosty as Earth's North Pole—has been discovered by a Penn State University astronomer using NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescopes. Images from the space telescopes also pinpointed the object's distance at 7.2 light-years away, making it the fourth closest system to our Sun.
"It is very exciting to discover a new neighbor of our solar system that is so close," said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State and a researcher in the Penn State Center for Exoplanets and Habitable Worlds. "In addition, its extreme temperature should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures."
Brown dwarfs start their lives like stars, as collapsing balls of gas, but they lack the mass to burn nuclear fuel and radiate starlight. The newfound coldest brown dwarf, named WISE J085510.83-071442.5, has a chilly temperature between minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius). Previous record holders for coldest brown dwarfs, also found by WISE and Spitzer, were about room temperature.
Although it is very close to our solar system, WISE J085510.83-071442.5 is not an appealing destination for human space travel in the distant future. "Any planets that might orbit it would be much too cold to support life as we know it" Luhman said.