Sh2-176 (Barnard's Loop), Sh2-264 (Lambda Orionis Nebula) in Orion

© Velimir Popov & Emil Ivanov 2020
Size: 1800 px

Sh 2-276 (Barnard's Loop) is an emission nebula in the constellation of Orion. Although this faint nebula was certainly observed by earlier astronomers, it is named after the pioneering astrophotographer E. E. Barnard who photographed it and published a description in 1894. It is part of the Orion Molecular Cloud Complex which also contains the dark Horsehead and bright Orion 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. The loop extends over about 600 arcminutes as seen from Earth, covering much of constellation Orion. Difficult to detect with the naked eye, it is well seen in long-exposure photographs. Recent studies place it at a distance of either 159 pc (518 light years) or 440 pc (1434 ly) giving it dimensions of either about 100 or 300 ly across respectively. It is thought to have originated in a supernova explosion about 2 million years ago, which 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 component exploded as a supernova. Sh2-264 (Lambda Orionis Nebula) is a molecular cloud and H II region in the northern region of the Orion Molecular Cloud Complex (OMCC). The nebula is named after its main star, λ Orionis, a blue giant responsible for the ionization of the surrounding material. It is also sometimes called the Angelfish Nebula due to its resemblance as to its lighter areas (pink to peach colour) to an angelfish.


Image details:


Center of field RA 05:43:03 (h:m:s)
Center of field DE -00:36:10 (deg:m:s)
Size 14.3 x 21.5 (deg)
Pixel scale: 42.9 (arcsec/pixel)
Orientation: Up is 357 degrees E of N
Charts and image details obtained from
Optic(s): 70mm Canon lens @ F/2.8
Mount: ASA DDM85 Standard
Camera: SBIG STL 11000 M
Filters: Ha, filter
Dates/Times: Dec. 2011
Location: IRIDA Observatory, BG, longitude: E 24 44' 18", latitude: N 41 41' 42"
Exp. Details: Ha:10x15 min; Bin 1 Total exp.time: 150 min. (2:30 hrs)
More details: Dark and flat frames reduction
Processing: PixInsight / PS
Copyright: Velimir Popov and Emil Ivanov 2020. All Rights Reserved
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