What happens when a star runs out of fuel to continue burning? The centre condenses into a white dwarf while the outer layers are expelled into space and appear as a planetary nebula. This one is called Shapley 1 after a famous astronomer Harlow Shapley and has a very obvious annular ring-like structure made up from the expelled outer layer. Although these nebula look a little like planets in the sky, they actually surround stars which are very far away from our solar system.