We knew about Star Latte CFBDSIR 1458 10b — a star so cold you could lick it — but NASA has now discovered an even colder star. So cold that you could wear a sweater if you were there.
The star is a brown dwarf, one of the the six classified as cool Y's. Its name is WISE 1828+2650, and it's the coldest ever discovered star at 25C. That's less than room temperature.
Sweater Star is one of the 100 brown dwarfs discovered by NASA's Wide-field Infrared Survey Explorer (WISE). The brown dwarfs begin their lives as normal stars but they can't accumulate enough mass to start ignition, remaining sad and cold in the sky. Y dwarfs are the coldest of them. [NASA]