The Coldest Known Star Is Only As Warm As What?
Answer: A Cup of Coffee
Star are normally searingly hot dynamos with temperatures in the thousands of degrees; our Sun, for example, has a surface temperature of around 10,000 F. However, Brown Dwarf stars are a different story altogether, as they are small stars that have failed to undergo the gravity-induced nuclear fusion process that generates such high temperatures in their bigger siblings.
The coolest Brown Dwarf on record is star CFBDSIR 1458 10b. This small star (though small is relative, as it is still over six times bigger than Jupiter) has a shockingly low temperature of 206 F, or about the same temperature of a fresh cup of coffee. CFBDSIR 1458 10b may not even hold the title of coldest star for long as scientists search for even cooler stars, some of which may have surfaces temperatures as low as 80 F.