NGC 2142 (also 3 Monocerotis, and HD 40967) is a magnitude +4.94 blue giant double star of spectral type B5III located 769 ±125 light-years away in the constellation Monoceros. The star orbits about 25,400 to 22,700 light-years from the galactic center. 3 Monocerotis has a companion star of magnitude +8.25, with a visual separation of 1.99 arcsec. The actual separation between them is at least 470 AU.
The star was discovered by British astronomer John Herschel using a 47.5 cm (18.7 inch) reflecting telescope at Windsor Road, Slough, on the 6th January 1831.
Right Ascension 06 01 50.3 Declination -10° 35' 51"
