Thor’s Helmet Nebula
NGC 2359 (also known as Thor’s Helmet) is an emission nebula in the constellation Canis Major. The nebula is approximately 15,000 light-years away and 30 light-years in size. The central star is the Wolf-Rayet star HD 56925, an extremely hot giant thought to be in a brief, pre-supernova stage of evolution. It is similar in nature to the Bubble Nebula, interactions with a nearby large molecular cloud are thought to have contributed to the more complex shape and curved bow-shock structure of Thor’s Helmet.