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Description of the Hercules Star Constellation

Hercules has been recognized as a constellation at least as far back as the second century. The Greeks called it Engonasin, the Kneeler, and Aeschylus, the great tragedian, imagined it to be the kneeling form of a wounded Hercules. The Alexandrian astronomer Ptolemy included it among his 48 original constellations in his book, the Almagest, around A.D. 150. Since then, astronomers have changed the kneeling Hercules to a standing one, but the constellation has remained much the same. It is now among the 88 official constellations described by the International Astronomical Union.

History
- Hercules was a hero in Greek and Roman mythology. According to the myth, he was the son of the chief god, Zeus, and the mortal Alcmene. Consequently, he lived on earth, but with the strength of a god. He was given many tasks by the king of Mycenae, including taking an apple from the garden of the Hesperides, which required him to kill the hundred-headed dragon that guarded it. The modern constellation pictures him standing over this dragon.
Location
- Hercules is visible all year in the Northern Hemisphere, and in portions of the Southern Hemisphere from May to August. It is the fifth largest constellation, behind Hydra, Virgo, Ursa Major and Cetus. It reaches its highest point in the northern sky in July. Nearby constellations include Draco, the dragon; Ophiuchus, the serpent-bearer; Corona Borealis, the northern crown; and Lyra, the lyre.
Stars
- Raselgethi and Kornephoros are Hercules' brightest stars. Raselgethi is at the bottom of his right leg, and is a binary star, which means that it orbits around a center of mass shared with a partner star. Kornephoros forms the right knee. Four stars in the center -- epsilon, zeta, eta and pi Herculis -- form a square body, the constellation's most recognizable structure.
Deep Space Objects
- The Great Globular Cluster, Messier 13, lies along the right edge of Hercules' body. It is the brightest cluster in the Northern Hemisphere, and contains several hundred thousand stars in a space 145 light-years in diameter. Another cluster, Messier 92, lies outside the constellation proper, but within the outlying stars belonging to it. As of June 2011, the hottest planet known to scientists, HD 149026b, also lies in Hercules. It's surface is estimated to be 3,700 degrees Fahrenheit -- hotter than some stars.

Astronomy