ABOUT THIS IMAGE:

The Thor’s Helmet Nebula, also known as NGC 2359, lies in the constellation of Canis Major (The Great Dog). The helmet-shaped nebula is around 15,000 light-years away from Earth and is over 30 light-years across. The helmet is a cosmic bubble, blown as the wind from the bright, massive star near the bubble's center sweeps through the surrounding molecular cloud. The glowing gas is heated by the energetic radiation provided by the central star. Many different colors, originating from different elements in the gas, are also visible, as well as many dust clouds.

From Wikipedia:

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. 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