George Johnstone Stoney, Lord Rosse's assistant, discovered NGC 2510 and 2511 on 31 Jan 1851. The group was sketched on 26 Feb 1851 with NGC 2510 is labeled Gamma and precise offsets were measured from NGC 2513.

400/500mm - 17.5" (2/13/88): faint, fairly small, irregularly round, even surface brightness. Similar size to NGC 2513 5.6' SE but lower surface brightness. In a group of five with NGC 2511 5.6' SSE.

600/800mm - 24" (3/22/14): faint to fairly faint, fairly small, elongated 3:2 WNW-ESE, ~40"x25", fairly low even surface brightness. First of 5 with NGC 2511 5.6' SSE, NGC 2513 5.6' SE, CGCG 59-27 6.7' ENE and PGC 1364011 7.5' S.

Notes by Steve Gottlieb