Pair of Galaxies NGC 5426/7 (Arp 271)

NGC 5426/7
NGC 5426/7: Pair of galaxies in Virgo; Hypergraph 400 mm f/8.3; STL 11000M; LRGB 70-50-50-50 min; Astrofarm Tivoli, Namibia; © 30 May 2011 Eduard von Bergen


As for most of the deep-sky objects also this pair of galaxies was discovered by William Herschel. He has cataloged these «faint nebulae» on 5 March 1785 as II 309 and II 310 and noted: «Two, nearly in the direction of the meridian, distance 4', small stars between, chevelure touching. Northern: pretty bright, considerably large, much brighter in the middle. Southern: faint, small.» [463] His son later cataloged these as h 1734 (GC 3750) and h 1735 (GC 3751). Dreyer added them as NGC 5426 and NGC 5427 in 1888. [313]

In 1966 Halton Arp published his «Atlas of Peculiar Galaxies». He divided the galaxies into groups based on purely morphological criteria. The pair of galaxies here belongs to the group #269-274 (double galaxies with connected arms) and received the designation Arp 271. He noted: «Arms linked. Note bifurcation in arm of N spiral.» [199]

NGC 5426/7
NGC 5426/7: Image taken in 2010 with the 3.58m New Technology Telescope in Chile. © ESO [553]

Physical Properties

NGC 5426 and NGC 5427 are two spiral galaxies of similar sizes and spiral structure. They are engaged in a dramatic dance and show tidal distortion. It is not certain that this interaction will end in a collision and ultimately a merging of the two galaxies. This dance will last for tens of millions of years, creating new stars as a result of the mutual gravitational attraction between the galaxies, a pull seen in the bridge of stars already connecting the two. At a distance of 90 million light-years the pair of galaxies is about 130 000 light-years across. [553]

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 542614 03 24.9-06 04 08Gx (Sc)12.712.13 × 1.7pF, cL, R, gmbM, sp of 2MCG -1-36-4, UGCA 380, VV 21, Arp 271
NGC 542714 03 26.0-06 01 51Gx (SBc)11.911.42.9 × 2.2pF, cL, R, nf of 2MCG -1-36-3, UGCA 381, VV 21, Arp 271, IRAS 14008-0547


The pair of galaxies is located in the constellation Virgo. The best time to observe it is January to June, when it is highest at night.

Chart Pair of Galaxies NGC 5426/7 (Arp 271)
Pair of Galaxies NGC 5426/7 (Arp 271) in constellation Virgo. Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

More Objects Nearby (±25°)


149SkySafari 6 Pro, Simulation Curriculum;
160The STScI Digitized Sky Survey;
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; (2021-02-17)
313«A New General Catalogue of Nebulae and Clusters of Stars, being the Catalogue of the late Sir John F.W. Herschel, Bart., revised, corrected, and enlarged» Dreyer, J. L. E. (1888); Memoirs of the Royal Astronomical Society. 49: 1–237; Bibcode:1888MmRAS..49....1D
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
553Arp 271 — galaxies drawn together; (2022-10-11)