The constellation Hercules lies between the bright stars Vega in Lyra and Arcturus in Boötes. A famous globular cluster, known as M13, lies on the Keystone, an asterism in Hercules. Chart via EarthSky.Hercules (Heracles for the Greeks) is the strong man of ancient Roman mythology. He was a son of Jupiter who had to perform the famous twelve labors. Astronomers know Hercules as a constellation high in the northern sky on July evenings that’s home to an asterism known as the Keystone, where ...
