NGC 2359 - Thor's Helmet

NGC 2359, also called Thor's Helmet, is a large nebula in the northeast portion of Canis Major. The object, about 30 light years in size, surrounds a large, hot, massive star which is believed to be close to exploding as a suprnova. Lying at a distance of 15,000 light years from Earth, the nebula seems to result from the interaction between the radiation from the star and a nearby molecular cloud of hydrogen. The star in the center of the bubble is known as a Wolf-Rayet star, which is pushing large amounts of its outer atmosphere away in all directions because of the powerful radiation streaming outward from its core.  The bubble, a very non-typical planetary nebula, glows green from oxygen, while the 'wings' of the helmet emit the teltale red of hydrogen gas.

Image is the result of 10 separate photos taken over 4 separate nights in mid-February, 2012 with the C-14 operating at F:3.5 (Meade focal reducer). LRGB combine done with Maxim DL. Luminous frame was taken with a hydrogen alpha filter - exposure 60 minutes. Red, Green, and Blue frames were 30 minutes each. The ST-8 camera was binned 2 X 2 for all frames.