Heinrich d'Arrest discovered NGC 2560 on 17 Mar 1862 with the 11" refractor at Copenhagen Observatory (recorded as #78 in AN 1500). His position (based on 4 measurements) matches UGC 4337 and he accurately placed the nearby mag 10.5 star as 7 seconds of time preceding.

400/500mm - 17.5" (2/8/91): faint, small, very elongated 3:1 E-W, small bright core. Located 4.5' NE of mag 7.9 SAO 116633. A mag 10.5 star is 1.5' W. Located near the core of the Cancer I galaxy cluster with NGC 2556 12' WSW.

Notes by Steve Gottlieb