Gamma Cygni Nebula IC 1318 & Open Cluster NGC 6910

History

The open star cluster NGC 6910 was discovered on October 17, 1786 by the German-British astronomer Wilhelm Herschel. He cataloged it as VIII 56 (Class VIII = coarsely scattered clusters of stars) and noted: «A small cluster of coarsely scattered stars of various sizes. Extended like a forming one.» [464] Due to its size and low brightness the galactic nebula IC 1318 was discovered much later photographically by the American astronomer Edward Barnard in August 1893. [196]

IC 1318, NGC 6910
IC 1318, NGC 6910: Gamma Cygni Nebula (IC 1318) and open cluster NGC 6910; Celestron RASA 11" f/2.22; ZWO ASI6200 Pro; Tentlingen; © 2020 Peter Kocher
IC 1318, NGC 6910
IC 1318, NGC 6910: Gamma Cygni Nebula (IC 1318) and open cluster NGC 6910; TS Triplet APO 90, Reducer Photoline 0.79 (490mm / f5.44), SBIG ST-8300; 24L x 300 sec 1×1, 14R, 14G, 12B 2×2 300 sec; Bernese Highlands; © 2018 Bernhard Blank, Dragan Mihajlovic
IC 1318
IC 1318: Gamma Cygni Nebula; 500 mm Cassegrain f=3625 mm f/7.2; SBIG STL11K; 290+3*60 min LRGB; Bernese Highlands; © 2015 Radek Chromik
IC 1318
IC 1318: Gamma Cygni Nebula; 500 mm Cassegrain f=3625 mm f/7.2; SBIG STL11K; 180+3*70 min LRGB; Bernese Highlands; © 2011 Radek Chromik

Physical Properties

NGC 6910 is a small star cluster with about 7.4 mag apparent magnitude, an angular expansion of about 8 arcminutes and the Trumpler type I2p. The distance is given by WEBDA with 1139 parsecs (around 3700 light years) and the estimated age with around 13 million years. [138, 196]

IC 1318 is a larger H-II nebula complex with emission nebulae and dark nebulae, which belongs to the large Cygnux-X star formation region. [196] The Gamma Cygni Nebula is the remnant of a supernova (SNR G78.2+2.1), which occurred here about 6'800-10'000 years ago and triggered the formation of new stars through this shock wave. The distance is about 1.7-2.6 kpc. The pulsar PSR J2021+4026 is located roughly in the center. The Cygnus-X area is also a source of radio and X-rays. [378]

«Revised New General Catalogue and Index Catalogue», «Historically Corrected New General Catalogue», Dr. Wolfgang Steinicke, 2021 [277]
NameRADecTypeBmagVmagDimDreyer DescriptionIdentification
NGC 6910 20 23 12.0+40 46 43OCL (I2p)7.410.00Cl, pB, pS, P, pC, st 10…12OCL 181
IC 1318 20 22 14.0+40 15 24EN50.00 × 30.0γ Cygni, surrounded by L patches of F nebyLBN 245, part of Gamma Cyg nebula
IC 1318 A20 16 36.0+41 49 00EN50.00 × 20.0γ Cygni, surrounded by L patches of F nebyLBN 251, part of Gamma Cyg nebula
IC 1318 B20 27 54.0+40 00 00EN14.945.00 × 30.0γ Cygni, surrounded by L patches of F nebypart of Gamma Cyg nebula

Finder Chart

As the name suggests, the Gamma Cygni Nebula (IC 1318) is located at the star γ Cygni (Sadr) in the constellation Cygnus (Swan). The best observation time is April to November.

Chart IC 1318
Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

References

138WEBDA, Sternwarte Genf; obswww.unige.ch/webda
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
196Celestial Atlas by Curtney Seligman; cseligman.com/text/atlas.htm (2020-12-28)
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
378«X-ray and radio observations of the γ Cygni supernova remnant G78.2+2.1» D. A. Leahy, K. Green, S. Ranasinghe Monthly Notices of the Royal Astronomical Society, Volume 436, Issue 2, 01 December 2013, Pages 968–977; DOI:10.1093/mnras/stt1596
464«Catalogue of a second thousand of new nebulae and clusters of stars; with a few introductory remarks on the construction of the heavens» William Herschel, Philosophical Transactions of the Royal Society of London, 1 January 1789; DOI:10.1098/rstl.1789.0021