John Herschel discovered NGC 2942 = h613 on 6 Mar 1828 (sweep 128) and logged "vF; vL; lE parallel to meridian; vgbM; has a * 10m following." His position and description matches UGC 5140.

400/500mm - 17.5" (3/12/94): faint, round, moderately large, 2.0' diameter, very weakly concentrated, halo reaches 2/3 of the way to a mag 14 star just 1.4' W of center. A mag 11.5 star is 3.0' ESE and a mag 12 star lies 4.6' WNW.

Notes by Steve Gottlieb