William Herschel discovered NGC 3507 = H IV-7 = h812 on 14 Mar 1784 (sweep 170). He described it as "F, pL. The nebulosity is of the milky kind. It situated between 2 bright stars but near the most north of them and to the south of that star. At first sight the nebula appears like an electric brush to the great star, but on examination I find it to have no connection with it. There is in the nebula, and pretty near the center of it, a vF star. The milky nebulosity is of a circular form." On 25 Mar 1827 (sweep 63), John Herschel called this object "a * 9m with vF neb attached; pos 70° sp = 200° +/- dist 30".

400/500mm - 17.5" (4/1/95): unusual appearance as a bright mag 10.5 star is superimposed very close to the center! Fairly faint, moderately large, 2.5' diameter, irregularly round. The core is difficult to view but is located just 30" SW of the superimposed star and the galaxy is slightly offset to the west side of the star. NGC 3501 lies 12.7' SW.

Notes by Steve Gottlieb