William Herschel discovered NGC 3956 = H III-290 = h3368 on 10 Mar 1785 (sweep 709) and logged "eF, pL, broadly elongated from a few degrees sp to nf." JH made a single observation and recorded "F; pL; mE; glbM; 60"; pos 236.8°." Both Herschels measured accurate positions.

400/500mm - 17.5" (5/11/96): fairly faint, fairly large, very elongated 7:2 SW-NE. Broad concentration with no well-defined core. Halo gradually fades into background, so difficult to estimate size but roughly 3.2'x1.0' (slightly larger than similar NGC 3955). Located 4.5' SE of mag 8.6 SAO 180275. Member of the NGC 4038/39 (Antennae) group.

Notes by Steve Gottlieb