Heinrich d'Arrest discovered NGC 3126 on 30 Apr 1864 and recorded "F, S, not lE, mag 15 nucleus. Confirmation still needed." This was his only observation, but his position matches UGC 5466. Otto Struve independently found the galaxy on 8 Apr 1869 at St Petersburg while searching for Comet Winnecke (7P/Pons-Winnecke). He recorded finding a "Bright elongated nebula with a stellar nucleus, a miniature image of the Andromeda Galaxy. 4.5' north is a mag 10-11 star with the nebula in PA of 168° [SSE]." He immediately added a note that this nebula was discovered by d'Arrest in 1864.

400/500mm - 17.5" (4/9/94): fairly faint, moderately large, edge-on 5:1 WNW-ESE, 2.0'x0.4', faint thin arms, fairly well-defined round core. A mag 11 star is 4.7' N of center. Located 15' N of mag 6.2 SAO 61882.

Notes by Steve Gottlieb