E.E. Barnard discovered IC 1870 on 28 Nov 1888 with the 12-inch refractor at Lick Observatory. He noted "vF, R, vgbM, v difficult" and made a rough sketch (in his logbook) with the nearby bright star. Barnard notified Dreyer directly of the discovery.

600/800mm - 24" (1/28/17): at 282x; fairly faint, moderately large, elongated NW-SE, ~0.9'x0.5', increases in size with averted vision. Contains a small brighter core. Low surface brightness but slightly irregular and patchy. Situated just 1.7' WSW of mag 7.7 HD 18463, which significantly interferes with the view! A mag 12 star is 1.6' NNW.

Notes by Steve Gottlieb