The coldest known star is "WISE 1828+2650," which is about 80° F (about 24° C), making it colder than a human body. The second-coldest star, "CFBDSIR 1458 10b," is about 200° F (about 97° C) — essentially the same temperature as a cup of coffee. To put that in perspective, most larger stars have a surface temperature of about 90,000 degrees Fahrenheit (about 50,000 degrees Celsius).
More facts about stars:
- Stars such as WISE 1828+2650 and CFBDSIR 1458 10b are often known as brown dwarfs or failed stars because they have many properties that stars have but not enough mass to start nuclear fusion in their cores.
- The dimmest known stars are a pair of brown dwarfs. Each is about one-millionth as bright as the sun.
- Most of the visible stars are actually revolving in pairs, usually with one smaller star circling a bigger star. These are known as binary pairs and are the most common type of star relationship, though some systems have three or more stars revolving together.