John Herschel discovered NGC 2809 = h578, along with NGC 2804, on 24 Feb 1827 (sweep 59) and noted, "vF; S; R; the s f of two, distant 8'." His position was marked as uncertain, but is a good match with UGC 4910. He missed nearby NGC 2807, which was discovered by d'Arrest while observing NGC 2809.

400/500mm - 17.5" (3/12/94): fairly faint, fairly small, round, 1' diameter, even moderate concentration down to very small bright core, faint stellar nucleus at moments. Located 2.9' SSE of a mag 10 star. A wide double star lies 4.5' W (mag 11/12 at 26"). Brightest in a group with NGC 2807 2.5' SSW and NGC 2804 8.6' NNW.

Notes by Steve Gottlieb