The Fate of the Stars
All scenes › Chapter 3 A heavy star: supernova and neutron star
Red supergiant
The 15-Sun star swells up huge and red
View in 3DRed supergiant
About 12 million years after birth, the 15-Sun star runs out of hydrogen in its center. Its outer layers swell up hugely and it becomes a red supergiant. It is about 800 times wider than the Sun. Put in the Sun’s place, it would reach far past the orbit of Mars, out beyond the asteroid belt. Its surface cools and turns red, but inside it gets even hotter.
Why?When the hydrogen in the center runs out, the center shrinks and heats up, and that heat pushes the outer gas so it swells. The swollen surface spreads out and cools, so it looks red.
Learn moreBetelgeuse, in the constellation Orion, is a red supergiant like this. It is expected to explode as a supernova one day, but no one knows whether that will be tomorrow or 100,000 years from now.
- When
- About 12 million years old
- Star we are watching
- 15-Sun star → red supergiant
- Size · state
- About 800 times wider than the Sun
Read more
Wikipedia: Red supergiant · Wikipedia: Betelgeuse
More in the series
Lifetimes and sizes are typical values from models of how stars change (approximate). The black hole horizon size and the teaspoon masses are calculated with official constants. Sizes, distances and speeds in the 3D view are a rough sketch.