John Herschel discovered NGC 2492 = h477 on 24 Dec 1827 (sweep 115) and logged "vF; S; R; bM." His position matches UGC 4138. Dorothy Carlson misidentified NGC 2492 as a star in her 1949 list of NGC Corrections.

400/500mm - 17.5" (2/20/88): fairly faint, small, slightly elongated, bright core. Forms a pair with NGC 2490 4.0' NW.

Notes by Steve Gottlieb