Pair of Galaxies NGC 5426/7 (Arp 271)
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.»  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. 
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.» 
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. 
|Name||RA||Dec||Type||bMag||vMag||B-V||SB||Dim||PA||z||D(z)||MD||Dreyer Description||Identification, Remarks|
|NGC 5426||14 03 24.9||-06 04 08||Gx (Sc)||12.7||12.1||0.6||13.7||3 × 1.7||172||0.008579||36.24||35.900||pF, cL, R, gmbM, sp of 2||MCG -1-36-4, UGCA 380, VV 21, Arp 271|
|NGC 5427||14 03 26.0||-06 01 51||Gx (SBc)||11.9||11.4||0.5||13.3||2.9 × 2.2||66||0.008733||36.89||33.750||pF, cL, R, nf of 2||MCG -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.