Hercules is the fifth largest constellation. Notable deep sky objects in Hercules include the Great Globular Cluster ( Messier 13), the globular cluster Messier 92, the planetary nebulae Abell 39 and NGC 6210, the Hercules Cluster of galaxies, and the galaxy cluster Abell 2199. Hercules constellation was first catalogued by the Greek astronomer Ptolemy in the 2nd century. The dragon is represented by the constellation Draco. In mythology, the constellation Hercules is usually associated with the penultimate labour of Heracles, which involved defeating the dragon Ladon, who guarded the garden of the Hesperides. In traditional depictions, the star Ras Algethi (Alpha Herculis) represents Hercules’ head and a prominent asterism, the Keystone, marks his torso, as he stands victoriously on Draco’s head. Hercules is the fifth largest constellation in the sky, but has no first magnitude stars. Heracles, in turn, was often associated with the Sumerian hero Gilgamesh, and the constellation itself has a long history, dating back to Sumerian times. It was named after Hercules, the Roman version of the Greek hero Heracles. Hercules constellation is located in the northern sky.
