R.J. Mitchell discovered NGC 870 (along with NGC 876) on 22 Nov 1854 with Lord Rosse's 72" and commented "I am pretty sure of the existence of an eeF patch of neby south [of NGC 871] and in line with its longer axis, but it needs confirmation". This nebula is shown on the sketch to the south of NGC 871 and marked as Beta.

400/500mm - 17.5" (12/18/89): not found

Notes by Steve Gottlieb