Pair of Galaxies NGC 770/2 (Arp 78)

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 29th 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 3rd 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]
NameRADecTypebMagvMagB-VSBDimPAzD(z)MDDreyer DescriptionIdentification, Remarks
NGC 77001 59 13.5+18 57 18Gx (E1)13.812.81.012.31.1 × 0.8150.00819934.6332.300vF, S, R, sp I 112UGC 1463, MCG 3-6-10, CGCG 461-16, Arp 78
NGC 77201 59 19.5+19 00 27Gx (Sb)11.110.30.813.97.2 × 4.31300.00824634.8330.310B, 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.

Finder Chart Pair of Galaxies NGC 770/2 (Arp 78)
Pair of Galaxies NGC 770/2 (Arp 78) in constellation Aries. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Visual Observation

635 mm Aperture: NGC 772 is recognizable as a faint, oval spot. There is no sign of one of its brighter arms. The small neighboring galaxy NGC 770 presents itself as a small, round, diffuse spot. — 25" f/4 Obession Dobsonian, Astrofarm Tivoli, Namibia, 15. 9. 2023, Bernd Nies

More Objects Nearby (±15°)

References