Thor’s Helmet
| Contributed by Francois Bernier from Marseille, France |
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Thor’s Helmet (NGC 2359) — perhaps the most impressive name for any deep-sky object — is a cosmic bubble sculpted by radiation from a type of luminous, massive star called a Wolf-Rayet star. These short-lived supergiant stars are rare; astronomers have discovered less than 250 of them within the Milky Way. As the star enters the Wolf-Rayet stage, a powerful stellar wind of up to 6 million mph (10 million kilometers per hour) ejects the star’s outer envelope. This gas slams into the surrounding interstellar medium and sculpts a beautiful shocked shell of ionized gas. (3.6-inch William Optics Megrez 90 Doublet APO refractor with a Tele Vue 0.8 focal reducer, Atik 314L+ CCD camera, Hydrogen-alpha/LRGB image with exposures of 21, 31, 26, 26, and 26 minutes, respectively)
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