Lewis Swift discovered NGC 5942 = Sw. VI-84, along with NGC 5940, -41 and -44, on 19 Apr 1887 and recorded "eeeF; S; R; eee diff; 3rd of 4." See notes for NGC 5941 on problems with the modern identifications.

400/500mm - 17.5" (7/7/94): very faint, very small, round, 20" diameter, stellar nucleus at moments. A mag 14.5 star is off the NW side 45" from center. This is the third brightest of four in HCG 76 with MCG +01-40-002 = HCG 76D 2.0' SE, NGC 5944 2.7' E and NGC 5941 1.8' NNE.

900/1200mm - 48" (5/20/17): at 375x; moderately to fairly bright, fairly small, round, well concentrated with a bright core that increases to a stellar nucleus. A mag 14 star is 45" NW. One of the three brightest members of the HCG 76 septet. NGC 5941 lies 1.6' NE. HCG 76D, situated 2' SE, appeared moderately bright, fairly small, round, bright core, stellar nucleus.

Notes by Steve Gottlieb