Albert Marth discovered NGC 2503 = m 112 on 17 Feb 1865 with Lassell's 48" on Malta and recorded "eF, S, glbM." His position is 8 sec of RA east of UGC 4158.

400/500mm - 17.5" (3/12/94): very faint, small, round, 0.8' diameter, low surface brightness, very weak concentration. A mag 14.5 star is at the NW edge and a mag 11 star lies 2.0' SE of center. Located on the Cancer/Gemini border.

17.5" (2/20/88): very faint, very small, round, diffuse, weak concentration. A mag 15 star is just off the NW edge and a mag 11 star is 2.0' SE.

Notes by Steve Gottlieb