Albert Marth discovered NGC 7475 = m 518, along with NGC 7474, on 9 Sep 1864 and noted "vF, S." His position is accurate.

400/500mm - 17.5" (9/2/89): faint, fairly small, elongated SW-NE. A mag 11 star is 1.7' NW. Forms a pair with NGC 7474 1.5' SW. The compact companion at the NE end was unresolved.

600/800mm - 24" (9/10/15): at 260x; fairly faint to moderately bright, fairly small, elongated 3:2 or 4:3 WSW-ENE, ~0.6'x0.4', contains a very small bright nucleus that appears offset to the southwest side. NGC 7474 lies 1.6' SE. A mag 11.5 star lies 1.7' NW.

With careful viewing this is clearly seen as a double system with a companion attached at the northeast end (MCG +03-58-028 = PGC 70382). It was visible as a faint, small, round glow, 12" in diameter. The centers of the galaxies are separated by just 27" and nearly collinear with NGC 7474.

Notes by Steve Gottlieb