James Dunlop discovered NGC 6400 = D 568 = h3696 on 13 May 1826 and described "a very faint cluster of very small stars, resembling faint nebula; the stars are considerably congregated to the centre, irregular round figure." Dunlop observed the cluster 3 times and his position is only a couple of arc minutes too far south. John Herschel observed the cluster on 28 Jun 1834 and recorded "Cluster class VII, p rich; pL, irr R, 8', stars 9..10m." His position is 0.6 minutes of time too small. The RNGC position is 0.6 minutes too far east.

200/250mm - 8" (6/27/81): faint, fairly small, fairly rich. Many stars are aligned in rows.

400/500mm - 17.5" (6/30/00): ~50 stars are resolved in an 8'x5' region at 220x. The stars are fairly uniform in brightness, though irregular in outline. The cluster is elongated N-S with a nice string extending through the cluster to the SSE and NNE with a slight bend near the center. At the kink in the center of the string is a denser clump of stars. There are circular voids on the NW and SW ends. The two brighter strings (on the following side) and two less distinct rows of stars create a vague "X" shape through the cluster with a loop of stars on the north end.

Notes by Steve Gottlieb