Concept · beginner
Red supergiant
A huge, cool, evolved star that has swollen after burning through much of its hydrogen fuel.
Red supergiants
Red supergiants are among the largest stars by radius. They are cooler at the surface than the Sun, which is why they look red, but they are enormously luminous because of their size.
They are late evolutionary stages for massive stars and often end as core-collapse supernovae.