NGC 7771 Galaxy Group

NGC 7769, NGC 7770, NGC 7771
NGC 7769, NGC 7770, NGC 7771: Galaxy group in Pegasus; 500 mm Cassegrain f/7.2; SBIG STL11K; 120-20-20-20 min LRGB; Bernese Highlands; © 2011 Radek Chromik

History

The three galaxies were discovered on 18 September 1784 by the German-British astronomer William Herschel with his 18.7 inch reflecting telescope. He cataloged them as II 230 (NGC 7769) and II 231 (NGC 7770 and NGC 7771). Herschels class II stood for faint nebulae. [277, 463]

Physical Properties

The galaxies are in gravitational interaction with each other. NGC 7771 is undergoing a massive star formation spurt, which may have been caused by the dwarf galaxy NGC 7770. This appears to be in the early stages of a merger with NGC 7771. The resulting tidal disturbances may have caused the apparent two-armed spiral pattern and forced a significant portion of the disk gas inward. [438] Distances range from 58 Mpc to 63 Mpc (189 to 205 million light years) [145]

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 776923 51 04.1+20 09 02Gx (Sb)12.812.03.2 × 2.7pF, pS, R, mbMUGC 12808, MCG 3-60-30, CGCG 455-54, IRAS 23485+1952, KCPG 592A, KAZ 346, KUG 2348+198A
NGC 777023 51 22.5+20 05 49Gx (S0-a)14.413.80.7 × 0.4vF, vS, iR, s of 2UGC 12813, MCG 3-60-34, CGCG 455-57, KUG 2348+198B, KAZ 347, NPM1G +19.0594
NGC 777123 51 24.6+20 06 44Gx (SBa)13.112.32.4 × 1.1pB, pL, E 84°, bM, n of 2UGC 12815, MCG 3-60-35, CGCG 455-58, IRAS 23488+1949, KCPG 592B, KAZ 348, KUG 2348+198C

Finder Chart

The NGC 7771 galaxy group is located in the constellation Pegasus. The best observation time is June to November, when it is highest at night.

Chart NGC 7771 Galaxy Group
NGC 7771 Galaxy Group in constellation Pegasus. Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

More Objects Nearby (±15°)

References

145SIMBAD astronomical database; simbad.u-strasbg.fr/simbad
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
438«A multiwavelength study of the starburst galaxy NGC 7771» Richard I. Davies, Almudena Alonso-Herrero, Martin J. Ward; Monthly Notices of the Royal Astronomical Society, Volume 291, Issue 3, November 1997, Pages 557–568; DOI:10.1093/mnras/291.3.557
463«Catalogue of one thousand new nebulae and clusters of stars» William Herschel, Philosophical Transactions of the Royal Society of London, 1 January 1786; DOI:10.1098/rstl.1786.0027