NGC 6738 is not a true cluster but an optical alignment of stars seen through various amounts of dust (see "NGC 6738: Not a real open cluster" in 2003A&A...406..893B).

John Herschel discovered NGC 6738 = h2027 on 29 Jul 1829 and noted "the central star (double) in a coarse and poor cluster." His position corresponds with HJ 1359, a wide unequal pair (9.1/12.6 at 18").

400/500mm - 17.5" (7/20/90): at 82x, 125 stars are visible. This cluster is bright and very large but scattered. Located between a mag 7.5 star and a mag 8 star with a 30' separation N-S. A nice string of fairly bright stars is between these two bright stars. Most of the cluster is west of this string but also a faint stream of stars is just following.

Notes by Steve Gottlieb