Ralph Copeland, while an assistant at Birr Castle, discovered NGC 3751 and 3 other members of "Copeland's Septet" on 5 Apr 1874. He noted "F; L; E 45° +/-". This galaxy is labeled Zeta on the constructed sketch in the 1880 publication. See NGC 3753.

Although NGC 3751 = UGC 6601, the UGC copied the coordinates and magnitude for CGCG 127-011 located 8' south, so this data is incorrect.

400/500mm - 17.5" (5/11/96): extremely faint and small, round, 20" diameter. Requires averted vision although easier to view than NGC 3754. Furthest southern member of Copeland's Septet. Located 2.0' WSW of a mag 13 star and 2.7' S of brightest member NGC 3753.

900/1200mm - 48" (4/16/15): moderately bright, small, slightly elongated N-S, 22"x16", very small bright nucleus, fairly high surface brightness. Southernmost member of Copeland's Septet.

Notes by Steve Gottlieb