Bindon Stoney, LdR's assistant, discovered NGC 4466 on 26 Feb 1851. While observing the M49 field he noted "a 3rd about 12' south of 2nd [NGC 4470] is elongated." The actual separation between[NGC 4470 and NGC 4466 is 8', but there are no other possible candidates. In the GC, JH added three numbers for what he assumed were three new objects found at Birr Castle, although only a single very rough position was given. Heinrich d'Arrest independently discovered this galaxy on 24 Apr 1865 and measured an accurate position. Dreyer assumed it was new, adding it as GC(S) 5653. The two GC designations were combined in the NGC and d'Arrest is credited with the discovery.

But Wolfgang Steinicke attributes WH with the discovery on 28 Dec 1787 (sweep 498, #44 = II-18). On the sweep he apparently found both[NGC 4470 (seen earlier on 23 Jan 1784) and NGC 4466, although the polar distances are only 2' apart.

400/500mm - 17.5" (4/18/87): faint, fairly small, very elongated ~E-W. Located 7.8' SSW of NGC 4470 and 18' SSW of M49.

Notes by Steve Gottlieb