Grus, constellation in the southern sky at about 22 hours right ascension and 45° south in declination. Its brightest star is Al Na’ir (from the Arabic for “the bright one”), with a magnitude of 1.7. This constellation was invented by Pieter Dircksz Keyser, a navigator who joined the first Dutch expedition to the East Indies in 1595 and who added 12 new constellations in the southern skies. Grus represents a crane.