NGC 2133 (also ESO 057-SC046, KMH90-1471) is a magnitude +12.0 open star cluster located in the constellation Mensa.
The cluster was discovered by British astronomer John Herschel using a 47.5 cm (18.7 inch) reflector at Feldhausen, Claremont, Cape Town, on the 24th November 1834.
Right Ascension 05h 51m 28.8s, Declination -71° 10' 30"
