What would happen if the sun broke away from the solar system and went out on its own?

All the planets in our solar system would lose orbit and freeze. All the planets would be in total darkness.

Have a good day! = )

Planets' orbits around the sun will slowly expand. It won't happen fast enough to save the Earth, but if Neptune edges far enough out it could become a home for humans, with some terraforming ... For about 2 billion years the sun will fuse helium into carbon and some oxygen, but there's less energy in those reactions