Wilhelm Tempel discovered NGC 4820 in 1882, along with NGC 4823 and 4829, while observing nearby NGC 4825. No position was given in the discovery note (list V), but the NGC position (communicated directly to Dreyer?) matches MCG -02-33-067 = PGC 44227. See notes for NGC 4823.

400/500mm - 17.5" (5/17/90): very faint, fairly small, very elongated 4:1 WNW-ESE. Forms a pair with NGC 4825 4.3' NE.

Notes by Steve Gottlieb