Mensa is a faint constellation in the southern sky, located between the constellations of Hydrus and Dorado. It was first catalogued by the Dutch astronomer Petrus Plancius in 1590. The constellation is named after the Latin word for 'TABLE', referring to its shape. Mensa is one of the faintest constellations in the night sky, with only two stars brighter than magnitude 4.5. It contains several deep-sky objects, including the globular cluster NGC 6397 and the open cluster NGC 6124.