William Herschel discovered NGC 6583 = H VII-31 = h2001 = h3739 on 26 May 1786 (sweep 566) and recorded "a cluster of very small, and pretty compressed stars, considerably rich; 2 or 3' diam, but twilight too strong to see it well." From the CGH, JH logged "oblong cluster, not v rich nor v compressed, but well insulated; stars 13m; 5' long; 4' broad." His position is accurate.

200/250mm - 8" (7/16/82): few faint stars resolved over haze, appear rich but stars too faint to resolve well.

400/500mm - 17.5" (8/1/92): fairly faint, small, very rich. Contains 30 mag 13-15 stars in a 3'x2' field. Appears elongated SSW-NNE due to string of five stars through the center. Also a curving string of a half-dozen stars extends out of the cluster to the west. Three mag 11-12 stars are a few arc minutes off the SE edge.

600/800mm - 24" (7/7/13): excellent, very rich cluster at 175x with at least 50 stars mag 12-15, many of which are arranged in long intersecting lanes. Three distinct strings of stars stand out. Some brighter stars are off the south side. NGC 6573 (asterism) lies 25' due west.

Notes by Steve Gottlieb