SuWt 2 planetary nebula, visible light image. The bright ring-like structure is a planetary nebula, where shells of glowing gases expand outwards from a massive central star. The central star here is a close binary system composed of two stars that completely circle each other every five days. This nebula is located 6,500 light-years from Earth in the constellation Centaurus. Image obtained using the National Optical Astronomy Observatory's telescope at the Cerro Tololo Inter-American Observatory in Chile.