John Herschel discovered NGC 6639 = h2011 on 31 Jul 1826 and noted "A closely clustering portion of the milky way, which is one continued cluster here." His position is a close match with this group of stars. Although listed as a cluster in the RNGC, the RA is 48 seconds too small.

400/500mm - 17.5" (7/24/95): unimpressive group of two dozen stars at 220x in a 5' region. The brightest mag 11 star is at the west side, with most stars mag 12.5-13.5. There are two small elongated subgroups of stars close NE and SE of the mag 11 star. Located in a rich field 5' NE of mag 8.8 SAO 161547. There are several richer pockets of stars, so this group appears to be another asterism.

Notes by Steve Gottlieb