Astronomy Picture of the Day -- NGC 2359: Thor's Helmet

NASA ^ | February 15, 2014 | (see photo credit)

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Explanation: 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 is about 30 light-years across. In fact, the helmet is more like an interstellar bubble, blown as a fast wind from the bright, massive star near the bubble's center sweeps through a surrounding molecular cloud. 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. Cataloged as NGC 2359, the nebula is located about 15,000 light-years away in the constellation Canis Major. The sharp image, made using broadband and narrowband filters, captures striking details of the nebula's filamentary structures. It shows off a blue-green color from strong emission due to oxygen atoms in the glowing gas.

[SunkenCiv]

[Credit & Copyright: Bob and Janice Fera (Fera Photography)]

[SunkenCiv]

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So let me see if I got this right. This is a PREsupernova, and it's blown a 30 light year wide hole in the interstellar medium?

When it finally does go nova, I'm guessing it will be one heck of a thump...

[dr_lew]

I used paint.net to overlay a screen shot of the image on the Starry Night view of the sky from my latitude ( i.e. Chicago . ) Note the nebula covers about 1/2 degree of declination, so it's about the size of the moon ... funny I never noticed it !