William Herschel discovered NGC 3286 = H III-917 = h722 on 9 Apr 1793 (sweep 1039) and recorded "Two [along with III-918 = NGC 3288], both vF, pS, R, lbM." On 9 Feb 1831 (sweep 323), John Herschel noted "vF; pS; R; pslbM; 15" [diameter]." His position is within 1' of CGCG 290-056 = PGC 31433. NGC 3284 is likely a duplicate observation. See that number.

400/500mm - 17.5" (4/9/94): fairly faint, small, round, moderate even concentration with a bright core and nonstellar nucleus. Located 4.9' NW of a mag 10.5 star. Forms a pair with NGC 3288 3.9' SSE.

Notes by Steve Gottlieb