Lewis Swift discovered NGC 6399 = Sw. I-66, along with NGC 6393 and 6394, on 7 Jul 1885 and recorded "vvF; vS; R." His position is 1' too far southwest.
400/500mm - 17.5" (6/18/88): faint, small, slightly elongated, bright core, very faint halo SSW-NNE. Forms a pair with NGC 6393 11.3' WNW.
Notes by Steve Gottlieb