NGC 2122 (also ESO 57-EN41) is a magnitude +10.4 open cluster and emission nebula located in the constellation Mensa.
The cluster was discovered by Scottish astronomer James Dunlop using a homemade 9-foot 22.86 cm (9 inch) f/12 speculum Newtonian reflector at Paramatta, New South Wales, Australia, on the 3rd August 1826.
Right Ascension 05h 48m 52.6s, Declination -70° 04' 12"
