201225 - Sh2-276 "Barnard's Loop"
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click image to enlarge
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ASTRO:
type=interstellar cloud complex, const=Orion, dist=1140 ly, size=200 ly IMAGE: location=EB Driveway, BrtlCls=4; moon=83% WxGb; exposure=DSLR OSC: 43x240s (2.9h), ISO1600, f/4.0 EQUIPMENT: camera=Nikon D90 (mod); optics=NIKKOR 55-200mm DX kit zoom @ 55mm; filter=IRIX LPS; mount=Celestron AVX EQ; guiding=(none) SOFTWARE: acquisition=Stellarium, APT, processing=DSS, PhotoshopCC |
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Barnard's Loop (catalogue designation Sh2-276) is an emission nebula in the constellation of Orion. It is part of the Orion molecular cloud complex which also contains the dark Horsehead, the bright Orion, and the reflection Casper nebulae. The loop takes the form of a large arc centered approximately on the Orion nebula. The stars within the Orion nebula are believed to be responsible for ionizing the loop, making it visible.
The loop extends over 600 arc-minutes as seen from Earth, covering much of the Orion constellation. It is best seen in long-exposure photographs, although observers under very dark skies may be able to see it with the naked (unaided) eye.
Spanning more than 20 arc-degrees across the sky, the loop is VERY large as seen from here on Earth. Recent estimates place it at a distance of 1140 light years, giving it a dimension of appx 200 ly across. It is thought to have originated from a supernova explosion about 2 million years ago. That explosion may have also created several known runaway stars, including AE Aurigae, Mu Columbae and 53 Arietis, which are believed to have been part of a multiple star system in which one of the component stars exploded as the source supernova.
Although this faint nebula was observed by earlier astronomers, it is named after the pioneering astrophotographer Edward E. Barnard who is generally regarded as the "father of modern astrophotography", and the first to photograph the loop and publish a description of it in 1894.
The loop extends over 600 arc-minutes as seen from Earth, covering much of the Orion constellation. It is best seen in long-exposure photographs, although observers under very dark skies may be able to see it with the naked (unaided) eye.
Spanning more than 20 arc-degrees across the sky, the loop is VERY large as seen from here on Earth. Recent estimates place it at a distance of 1140 light years, giving it a dimension of appx 200 ly across. It is thought to have originated from a supernova explosion about 2 million years ago. That explosion may have also created several known runaway stars, including AE Aurigae, Mu Columbae and 53 Arietis, which are believed to have been part of a multiple star system in which one of the component stars exploded as the source supernova.
Although this faint nebula was observed by earlier astronomers, it is named after the pioneering astrophotographer Edward E. Barnard who is generally regarded as the "father of modern astrophotography", and the first to photograph the loop and publish a description of it in 1894.