M 42 ( NGC 1876, Sh2-281,Great Orion Nebula), NGC 1977 (Sh2-279) in Orion

© Velimir Popov & Emil Ivanov 2020
Size: 1800 px

The Orion Nebula (also known as Messier 42 or M 42, NGC 1976, Sh2-281) is one of the brightest diffuse nebulae in the night sky. Clearly recognizable to the naked eye as an object of non-stellar nature, it is located south of the famous asterism of the Orion Belt, in the center of the so-called Sword of Orion, in the homonymous constellation. Located at a distance of about 1270 l.y. from the Earth, it extends for about 24 light years and is the star forming region closest to the Solar System. It is one of the most photographed and studied objects of the sky, and is under constant control because of the celestial phenomena that take place inside; astronomers have discovered protoplanetary disks, brown dwarfs and intense movements of gas and dust in its innermost regions. The Orion Nebula contains a very young open cluster, known as the Trapezium. Observations with the most powerful telescopes (especially the Hubble Space Telescope) revealed many stars surrounded by rings of dust, probably the first stage in the formation of a planetary system. The nebula was recognized as such in 1610 by a French lawyer, Nicolas-Claude Fabri de Peiresc (1580-1637), although, given the size and brightness, it was certainly known even in prehistoric times. Ptolemy identified it as a star of the sword of Orion, of magnitude 3. Sh2-279 (alternatively designated NGC 1977) is an HII region and bright nebulae that includes a reflection nebula located in the constellation Orion (lower left part of the image). It is the northernmost part of the asterism known as Orion's Sword, lying 0.6° north of the Orion Nebula. The reflection nebula embedded in Sh2-279 is popularly known as the Running Man Nebula. Sh2-279 comprises three NGC nebulae, NGC 1973, NGC 1975, and NGC 1977 (see mouseover) that are divided by darker nebulous regions. It also includes the open cluster NGC 1981. The brightest nebulosity, later listed as NGC 1977, was discovered by William Herschel in 1786. He catalogued it as "H V 30" and described "!! 42 Orionis and neb(ula)". The two smaller reflection nebulae were first noted by German astronomer Heinrich Louis d'Arrest, NGC 1973 in 1862 and NGC 1975 in 1864. All three were included in the New General Catalogue in 1888. The designation NGC 1977 is used in various sources for the reflection area around 42 Orionis (the south-east portion of the reflection nebula), for the entire reflection nebula (including NGC 1973 and NGC 1975), or for the whole nebula complex. This whole region in Orion's Sword was also later catalogued as Orion 1c. In 1966, van den Bergh distinguished the weak clustering of reflection nebulae that includes Sh2-279 as Ori R2. Every reflection nebula appearing within the Sharpless catalogue was first identified on blue plates of the Palomar Sky Survey, and then double checked against the red plates to eliminate possible plate faults. Van den Berg found that there was a strong concentration of new T Tauri stars around the Orion Nebula, tapering off into a tail approaching Sh2-279. The Running Man Nebula is also a popular target for amateur astrophotographers, as it lies close to the Orion Nebula and has many nearby guide stars. The outline of the running man shows up primarily in photographs; it is difficult to perceive visually through telescopes, though the reflection nebula itself is visible in small to medium apertures in dark skies. Higher res. image, showing the central part of M42, taken with the 12" RC telescope can be seen here.


Image details:


Center of field RA 05:34:58 (h:m:s)
Center of field DE -05:24:24 (deg:m:s)
Size 1.89 x 1.26 (deg)
Pixel scale: 3.78 (arcsec/pixel)
Orientation: Up is 96.6 degrees E of N
Charts and image details obtained from Astrometry.net
Optic(s): 12" ASA Astrograph at F/3.6
Mount: ASA DDM85 Standard
Camera: SBIG STL 11000 M
Filters: Luminance, Red, Green, Blue, Astronomik filters;
Dates/Times: Dec. 2011
Location: IRIDA Observatory, BG, longitude: E 24 44' 18", latitude: N 41 41' 42"
Exp. Details: L:6x10 min,;R:6x10 min, G:6x10 min, B:6x10 min;, Bin 1 Total exp.time: 240 min. (4 hrs)
More details: Dark and flat frames reduction
Processing: PixInsight / PS
Copyright: Velimir Popov and Emil Ivanov 2020. All Rights Reserved
e-mail: info@irida-observatory.org
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