210117 - Sh2-157 "Lobster Claw" nebula and Sh2-162 "Bubble" nebula
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click image to enlarge
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ASTRO:
type=Emission nebula mag=(unk) const=Casseopeia dist=8000 ly; size=140 ly IMAGE: location=EB Driveway BrtlCls=5 moon=23% WxCr exposure=DSLR OSC 22x300s (1.8 h), ISO1600 EQUIPMENT: camera=Nikon D90 (mod) Optics=ES102 w0.8x rdcr, F=571mm, f/5.6 filter=STC Astro DuoNB mount=Celestron AVX guiding=Orion 60x240mm, ZWO ASi224MC SOFTWARE: acquisition=Stellarium, APT, PHD2, processing=DSS, PhotoshopCC, RCAstro_GradXT & NoiseXT |
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Sharpless 157 (or Sh2-157), sometimes referred as the "Lobster Claw" nebula, is an emission nebula in the constellation Cassiopeia, at a distance of appx 8,000 light years from the Earth. The predominantly red part of the nebula is a very large H-II region that is ring-shaped by the stellar wind of several giant stars, including the bright and very young Wolf-Rayet star, WR 57. The lightly colored regions at the right part of the nebula mainly consist of highly ionized oxygen (O-III) and other gases. The small open star cluster NGC 7510 is located toward the bottom right.
NGC 7635, also known as the Bubble Nebula, and Sharpless 162 (or Sh2-162), and Caldwell 11 (or C11), is an H-II region emission nebula also in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, magnitude 8.7 young central star, SAO 20575. The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to also glow. The hot central star is thought to have a mass appx 44 x that of our Sun.
With an 8 or 10-inch (250 mm) telescope, both nebulae are visible as extremely faint shells. A nearby 7th magnitude star to the west of the Bubble hinders observation, but one can view both nebulae using averted vision. Using a 16 to 18-inch (460 mm) telescope, one can see that the faint nebulae are irregular, and elongated in the north-south direction.
NGC 7635, also known as the Bubble Nebula, and Sharpless 162 (or Sh2-162), and Caldwell 11 (or C11), is an H-II region emission nebula also in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, magnitude 8.7 young central star, SAO 20575. The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to also glow. The hot central star is thought to have a mass appx 44 x that of our Sun.
With an 8 or 10-inch (250 mm) telescope, both nebulae are visible as extremely faint shells. A nearby 7th magnitude star to the west of the Bubble hinders observation, but one can view both nebulae using averted vision. Using a 16 to 18-inch (460 mm) telescope, one can see that the faint nebulae are irregular, and elongated in the north-south direction.