William Herschel discovered NGC 3780 = H I-227 = h929 on 14 Apr 1789 (sweep 920) and recorded "pB, cL, iF, r, 3' by 2'. JH made two observations, noting on sweep 345, "F; L; R; vglbM; 60". Twilight."

400/500mm - 17.5" (4/6/91): moderately bright, moderately large, elongated 3:2 SW-NE, weak concentration, uneven surface brightness [images reveal a face-on multiarmed spiral]. A mag 13 star is off the ENE side 2.1' from center. Forms a pair with NGC 3804 13' ESE.

Notes by Steve Gottlieb