John Herschel discovered NGC 4539 = h1338 on 17 Mar 1831and logged "pB; pmE." His position and description matches UGC 7735.

400/500mm - 17.5" (4/13/02): fairly faint but fairly large, elongated 5:2 E-W, 2.4'x0.9'. Fairly uniform low surface brightness but bulges slightly at the core. Two mag 14 stars are 1.5' SE of center. Located 13' SW of the beautiful double 24 Comae (5.0/6.6 at 20").

Notes by Steve Gottlieb