DeLisle Stewart discovered IC 4721 = D.S. 474 on a plate taken on 14 Sep 1901 at Harvard's Arequipa Station. He noted "F, cL, E at 150°, form of Andromeda neb."

600/800mm - 30" (11/3/10 - Coonabarabran, 264x): fairly bright, large, elongated 3:1 NW-SE, 4.0'x1.3', broad concentration with a large, mottled core, irregular surface brightness with a hint of spiral structure. A faint star is embedded on the southeast side and a mag 15 star is just south of the southeast end. IC 4721 forms a very close pair with IC 4721A, 2.2' SSE of center. It appeared faint, very small, round, 20" diameter. The mag 15 star mentioned above is 20" NE. IC 4720, another highly inclined spiral, lies 8.5' NW. IC 4721 is located 15' NE of mag 6.4 HD 170525 in a fairly rich star field with many mag 11-14 stars.

Notes by Steve Gottlieb