Thor's Helmet
Thor's Helmet, also known as NGC 2359, is an emission nebula located approximately 15,000 light-years away in the constellation Canis Major. Spanning about 30 light-years, this helmet-shaped cosmic cloud is formed by the powerful stellar winds from a central Wolf-Rayet star, which sculpt the surrounding molecular cloud into a bubble-like structure.
Source: apod.nasa.gov
APODs including "Thor's Helmet"
Thor's Helmet Emission Nebula
01/11/2017
This helmet-shaped cosmic cloud with wing-like appendages is popularly called Thor's Helmet. Heroically sized even for a Norse god, Thor's Helmet spans about 30 light-years across. In fact, the helmet is more like an interstellar bubble, blown as a fast wind -- from the bright star near the center of the bubble's blue-hued region -- sweeps through a surrounding molecular cloud. This star, a Wolf-Rayet star, is a massive and extremely hot giant star thought to be in a brief, pre-supernova stage of evolution. Cataloged as NGC 2359, the emission nebula is located about 12,000 light-years away toward the constellation of the Big Dog (Canis Major). The sharp image, made using broadband and narrowband filters, captures striking details of the nebula's filamentary gas and dust structures. The blue color originates from strong emission from oxygen atoms in the nebula. Follow APOD on: Facebook, Google Plus, Instagram, or Twitter