William Herschel discovered NGC 3791 = H III-609 = h935 on 22 Feb 1787 (sweep 705) and recorded "vF, vS, R, gbM. 240 showed it very plainly." His RA is 30 sec too small and falls very close to NGC 3771!. JH's position and description ("vF; R; gbM; 20"; has a * 8m 6' south, on the same meridian") matches MCG -01-30-020 = PGC 36156.

400/500mm - 17.5" (5/2/92): fairly faint, fairly small, slightly elongated, gradually brighter halo, small bright core. Located 6.0' N of mag 7.4 SAO 138326. Forms a pair with NGC 3771 8' W. Member of a large group (USGC S171).

Notes by Steve Gottlieb