The Hottest Stars Burn Nearly 40 Times Hotter Than the Sun

Our Sun's surface is about 5,500 degrees. Some stars make that look ice-cold.

Scattered across the galaxy are rare, dying giants called Wolf-Rayet stars, with surfaces blazing at over 200,000 degrees Celsius, almost 40 times hotter than the Sun.

These stars are monsters nearing the end of their lives. They've blown away their cooler outer layers, exposing the scorching core beneath, which is why their surfaces are so extreme. They burn through their fuel at a furious rate, shining hundreds of thousands of times brighter than the Sun. But there's a catch you can't see. Most of their light pours out as ultraviolet radiation, invisible to human eyes. So the galaxy's hottest surfaces don't even look the brightest to us.

And they live fast. A star this hot may last only a few hundred thousand years, a blink in cosmic time, before exploding as a supernova. The hottest stars are also among the most short-lived.

Follow The Cosmic Vault — the universe is stranger than you think.