Several of the constellations currently recognized by astronomers have been passed down to us from antiquity. Well-known figures such as Orion the hunter and Capricornus the centaur were known to the ancient Greeks and Romans, and even —under other names — farther back. Many of these constellations are shrouded in legend and lore, finding their way into tales that are still retold to this day. No other constellation is as steeped in myth, though, as Hercules, the strongman.
Best visible in the summertime, Hercules is the fifth largest constellation in the night sky. Most often depicted as a kneeling musclebound hero wielding a massive club, Hercules sits in the sky surrounded by Draco, BoÃ¶tes, Corona Borealis, Serpens Caput, Ophiuchus, Aquila, Sagitta, Vulpecula, and Lyra.
Hercules contains 106 stars, 22 of which form its shape. The constellation contains no first magnitude stars. Its brightest star is Beta Herculis, also known as Kornephoros, a second magnitude star that is actually a binary system of two stars.
Hercules is notable because at least 11 of its stars are known to be orbited by planets, all of which have been discovered since 1996. It is also home to two Messier Objects, bright deep sky objects identified primarily by French astronomer Charles Messier during the 18th Century: the globular clusters M13 and M92. M13 is the brightest globular cluster in the Northern Hemisphere, containing 300,000 stars.
The quadrangle that makes up the lower half of Hercules’s torso is a popular asterism on its own, known as “the Keystone.”
Hercules gets its name from the Roman spelling of Heracles, a Greek hero who is the star of many myths. He was conceived from the union of the god Zeus and the mortal woman Alcmene, wife of Amphitryon, the king of Thebes. He had a fraternal twin half-brother, Iphicles, who was wholly mortal. Throughout his life, Hercules revered his father, Zeus. The kneeling pose the hero takes in most renderings of his constellation is said to represent him kneeling in prayer, asking for his father’s favor in battle (of course, devotion only goes so far, which is why his club is raised to strike, even as his head is bowed).
Hercules’ divine parentage imbued him with superhuman strength. He often slew giants and other monsters to protect the Greeks, but he also had a dark side. The goddess Hera, wife of Zeus, hated Hercules because she was jealous of Zeus’s affairs with mortal women, and she often drove Hercules to madness.
In one such instance, Hercules flew into a rage and murdered his own children. As a penance for his crime, Hercules was given twelve seemingly impossible labors to complete. Some versions of the story say it was initially ten labors, but that two more were added on at the end because Hercules received help with one, and was willing to accept payment for another.
Despite the super-sized flaws that matched his super-sized muscles, Hercules was one of Ancient Greece’s most popular folk heroes. Though Greek mythology is filled with accounts of demigod heroes, born to a human mother and celestial father, none had lives quite as storied as Hercules. And while other heroes, such as the demigod Perseus, are also immortalized in the night sky, the reputation of Hercules was so much larger than life that his story spills out of his own corner of the sky and across the whole of the heavens.
Snippets of Herculean myths can be seen in the lore surrounding such constellations as Hydra and Leo, both of which are monsters the hero slew. In fact, according to some astrologers, the 12 signs of the Zodiac are said to represent Hercules’ famous Twelve Labors — one sign for each task.