William Herschel discovered NGC 3205 = H II-721 = h699 on 3 Feb 1788 (sweep 804) and noted "F, vS, stellar." On 12 Apr 1830 (sweep 248) John Herschel recorded, "vF; R; vgbM; 30"; the second of 3 [with NGC 3202 and 3207] in a triangle."

400/500mm - 17.5" (4/9/94): second of three in a group. Very similar appearance to NGC 3202 4.4' NW. Fairly faint, small, elongated 3:2 SW-NE. A mag 13 star is 1.0' WSW. Appears to have a slightly higher surface brightness than NGC 3202 and brighter along the major axis. A threshold star is superimposed NE of the core (GSC shows a mag 15 star 15" NE of center). NGC 3207 lies 2.1' ENE.

Notes by Steve Gottlieb