William Herschel discovered NGC 3636 = H II-550 = h862, along with NGC 3637, on 4 Mar 1786 (sweep 597) and recorded "Two, stellar, vF, vS. A considerable bright star is situated between them, but about 1' south of the line that connects them."

Andrew Ainslie Common found the pair in 1880 and reported them as "2 planetary nebulae, B star between" in his Copernicus discovery list.

400/500mm - 17.5" (3/29/85): moderately bright, very small, bright core, round. Located just 1.8' NW of mag 6.6 SAO 156618! Forms a pair with similar NGC 3637 3.8' ENE.

Notes by Steve Gottlieb