John Herschel discovered NGC 7645 = h3988 on 27 Sep 1834 and logged "vF; S; R: glbM; 15"." His position is accurate.
400/500mm - 17.5" (10/13/90): very faint, small, slightly elongated NW-SE, weak concentration. NGC 7636 lies 17.3' WNW.
Notes by Steve Gottlieb