William Herschel discovered NGC 5116 = H III-368 = h1590 on 11 Apr 1785 (sweep 396) and remarked "vF, mE, about 1.5' long, r. I stopped to gage otherwise I might perhaps have overlooked it." JH made two observations and noted "not vF; pmE; lbM; 30" l; pos 40° inclined to the parallel.

400/500mm - 18" (6/21/03): fairly faint, moderately large, elongated 3:1 SW-NE, 1.3'x0.4'. Broad concentration with a brighter core and fainter, tapering extensions. A mag 12 star lies 2' NW. Forms a pair with IC 4234 8' N at 215x in the 18' field (10.5 Pentax XL).

Notes by Steve Gottlieb