Pair of Galaxies NGC 770/2 (Arp 78)

NGC 772
NGC 772: Galaxy in Aries; 500 mm Cassegrain f/7.2; SBIG STL11K; 130-40-40-40 min LRGB; Bernese Highlands; © 2011 Radek Chromik

History

The galaxy NGC 772 was discovered on 29 November 1785 by the German-British astronomer William Herschel with his 18.7 inch reflector telescope. The small companion galaxy NGC 770 remained undiscovered until 3 November 1855. During that night it was discovered by the Irish astronomer RJ Mitchell using Lord Rosse's large 72 inch reflector telescope. [196, 277]

In Halton Arp's 1966 Atlas of Peculiar Galaxies, the two galaxies are listed as Arp 78, a spiral galaxy with a small companion with high surface brightness. [199]

Physical Properties

The two galaxies interact gravitationally with one another and are about 36 Mpc away. [145, 439]

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 77001 59 13.5+18 57 18Gx (E1)13.812.81.1 × 0.8vF, S, R, sp I 112UGC 1463, MCG 3-6-10, CGCG 461-16, Arp 78
NGC 77201 59 19.5+19 00 27Gx (Sb)11.110.37.2 × 4.3B, cL, R, gbM, rUGC 1466, MCG 3-6-11, CGCG 461-18, KARA 80, Arp 78, IRAS 01565+1845

Finder Chart

The galaxy NGC 772 is located in the constellation Aries. The best time to observe is August to February, when it is highest at night.

Chart Pair of Galaxies NGC 770/2 (Arp 78)
Pair of Galaxies NGC 770/2 (Arp 78) in constellation Aries. 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
196Celestial Atlas by Curtney Seligman; cseligman.com/text/atlas.htm (2020-12-28)
199«Atlas Of Peculiar Galaxies», Halton Arp, 1966; Astrophysical Journal Supplement, vol. 14, p.1 (1966); DOI:10.1086/190147; Bibcode:1966ApJS...14....1A
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
439«The Interacting System NGC 7753--7752 (Arp 86). II. N-Body Modeling» Salo, Heikki ; Laurikainen, Eija; Astrophysical Journal v.410, p.586, June 1993; DOI:10.1086/172777