Dumbbell Nebula. Optical image of the Dumbbell planetary nebula (M27). Despite its name, it has nothing to do with a planet. Instead it comprises a shell of gas ejected from a star near the end of its life. The star then becomes a white dwarf (not seen), and its radiation causes the ejected gas layers to glow. It is thought the gas layers were ejected from the central star around 4000 years ago. This planetary nebula lies around 1000 light years from Earth in the constellation Vulpecula.