Coldest Brown Dwarf Star Near Our Sun is as Frosty as Earth's North Pole

The NASA Wide-field Infrared Survey Explorer (WISE) has discovered the coldest star of its kind just 7.2 light years from our own sun. As frosty as Earth's North Pole, the brown dwarf star is the fourth closest system to our sun.

Brown dwarfs start their lives like normal stars. They are created when gas collapses on itself. Yet these brown dwarf stars lack the mass to burn nuclear fuel and radiate starlight. This causes them to actually be cold rather than hot like the stars we're used to seeing.

In this case, the star is called WISE J085510.83-071442.5. Its temperature is chilly and ranges between minus 54 and 9 degrees Fahrenheit. This is the coldest brown dwarf discovered yet; other  previous brown dwarfs that have been discovered have hovered more around room temperature.

"It is very exciting to discover a new neighbor of our solar system that is so close," said Kevin Luhman, one of the researchers, in a news release. "In addition, its extreme temperature should tell us a lot about the atmosphere of planets, which often have similarly cold temperatures."

Yet while the brown dwarf could tell us a bit more about other planets, it couldn't help support any life itself. Any planets orbiting WISE J085510.83-071442.5 would simply be too cold to support life as we know it.

The star is estimated to be about three to 10 times the mass of Jupiter-a mass that's extremely low for a star. This makes WISE J085510.83-071442.5 not only one of the coldest stars known, but also one of the least massive brown dwarfs known.

"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, project scientist for Spitzer, in a news release. "This exciting new result demonstrates the power of exploring the universe using new tools, such as the infrared eyes of WISE and Spitzer."