Lewis Swift discovered NGC 6306 = Sw. II-51 on 8 Jul 1885 and recorded "vF; vS; lE. Close to 4278 [NGC 6310]. South-preceding of 2 [with[NGC 6310]. Dreyer assumed the "North-following" of two" referred to NGC 6307, but his position and description of Sw. II-52 applies to[NGC 6310. If that's the case, then his comment "close to 4278", should read "close to 4277 NGC 6307]."

400/500mm - 17.5" (6/18/88): fairly faint, fairly small, very elongated ~N-S, bright core. Forms a close pair with NGC 6307 1.4' NE.

Notes by Steve Gottlieb