Heinrich d'Arrest discovered NGC 4523 on 19 Apr 1865 with the 11-inch refractor at Copenhagen. His published position is 10 sec of RA west of UGC 7713, though he mentions his first observation (of 2) differed to 10 sec. In any case, there is no question about the identification as he mentions a double star on the south side of the nebula and a brighter star on the north.

400/500mm - 17.5" (5/23/87): extremely faint, difficult, very diffuse, moderately large. Located 10' S of IC 800. Three stars are involved; a mag 12 star is 0.4' NE of center and an evenly matched mag 13.5 double star at 21" separation is 0.7' S of center.

Notes by Steve Gottlieb