NGC 2004 (also known as ESO 86-SC4) is an open cluster of stars in the southern constellation of Dorado. It was discovered by Scottish astronomer James Dunlop on September 24, 1826.[6] This is a young, massive cluster with an age of about 20 million years and 23,000 times the mass of the Sun.[5] It has a core radius of 2.85 ± 0.46 pc (9.3 ± 1.5 ly).[7] NGC 2004 is a member of the Large Magellanic Cloud,[4] which is a satellite galaxy of the Milky Way.