NGC 2359

NGC 2359 is an emission nebula in the constellation Canis Major. The nebula is approximately 15,000 light-years away and 30 light years in size. Known as a Wolf-Rayet star, the central star is 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.
It is also Sharpless catalog Sh2-298 and Gum catalog 4.