NGC 2240 is a bright open cluster located in the constellation of Monoceros, also known as the Unicorn. It was discovered by the astronomer William Herschel in 1785. This cluster is approximately 2,000 light-years away from Earth and contains several hundred stars that are loosely bound by gravity. The stars in NGC 2240 are relatively young, with ages estimated to be around 100 million years. The cluster spans about 20 light-years across and is best observed with binoculars or small telescopes. Its position in the sky makes it a popular target for amateur astronomers.