Lawrence Parsons, the 4th Earl of Rosse, discovered NGC 4870 on 1 Apr 1878 during the observation of the NGC 4914 field. He noted "About 10' p and 10' s of last [NGC 4893] is a third neb, pF, lE ns, bet 2 st 10m, one about 1.5' npp and the other 2' f." His description is an exact match with this faint edge-on. The PGC declination is 3' too small.

400/500mm - 16" LX200 (4/14/07): extremely faint, very small, slightly elongated N-S, 0.4'x0.3'. Situated between two mag 11 stars 1' NW and 1.9' ESE. Located 12' SE of NGC 4893 and 23' SE of NGC 4914 in a small group of galaxies ~80' SE of Cor Caroli.

Notes by Steve Gottlieb