Lewis Swift discovered NGC 6100 = Sw. IV-28 on 3 Jul 1886 and recorded "eeF; vS; a B and a F * nr np. point to it; an eeF * close p; e diff.". His position is 9 seconds west and 1.7' north of UGC 10307 and his description applies, although the "eeF * close p" should read close following.

400/500mm - 17.5" (6/11/88): faint, very small, slightly elongated NW-SE, stellar nucleus. A mag 15 star is at the east end. A wide unequal double star is 1.5' NW consisting of a mag 9.5/13 pair at 30" separation.

Notes by Steve Gottlieb