Lewis Swift discovered NGC 6391 = Sw. IV-54 on 1 Sep 1886 and logged "eF; vS; R; nearly bet 2 stars." His position is 13 seconds of time too far west. The two stars he mentions are 3.2' south and 3.0' northwest.

400/500mm - 17.5" (6/18/88): very faint, very small, round, bright core, very faint stellar nucleus.

Notes by Steve Gottlieb