William Herschel discovered NGC 3099 = H III-478 = h664 on 7 Dec 1785 (sweep 487) and noted "eF, S, left doubtful." His position is accurate.

400/500mm - 17.5" (4/9/94): very faint, small, round, easily held with direct vision, very weak even concentration down to a slightly brighter nucleus. A mag 15 star is 2.7' N. Located 17' WNW of mag 7.6 SAO 61840. Forms a double system with MCG +06-22-058 = Ho 160b 1.4' NW.

Notes by Steve Gottlieb