Betelgeuse

red supergiant · star · Orion constellation · variable star

A red giant star. Betelgeuse is a massive red supergiant located in the constellation Orion, making it one of the most famous stars in the night sky. It's so enormous that if you placed it where our sun is, it would stretch out past Mars.

Super bright and red. Usually it's the tenth brightest star we can see from Earth, and it glows with a distinctive reddish color. This red glow comes from being cooler than most stars, even though it's still incredibly hot by Earth standards.

Its brightness changes. Betelgeuse doesn't shine at the same brightness every night. Its brightness varies in a regular pattern with a main cycle of about 400 days, which means it gets brighter and dimmer in a dance that repeats regularly.

Champion infrared star. When scientists look at Betelgeuse through special infrared cameras that see heat rather than visible light, it's the brightest star in the entire sky. This is because red supergiants emit a lot of their energy as infrared radiation.

The next big explosion. Betelgeuse is so massive and old that it could explode as a supernova sometime in the next million years, creating one of the brightest events in the galaxy. When it happens, it will briefly outshine entire galaxies.