Shapley 1: An Annular Planetary Nebula
Explanation : What happens when a star runs out of nuclear fuel ? The center condenses into a white dwarf while the outer atmospheric layers are expelled into space and appear as a planetary nebula . This particular planetary nebula , designated Shapley 1 after the famous astronomer Harlow Shapley , has a very apparent annular ring like structure. Although some of these nebula appear like planets on the sky (hence their name), they actually surround stars far outside our Solar System .