Hercules is the fifth largest of the 88 modern constellations.
It was also one of Ptolemy's 48 constellations. It was named
after the Roman name (Hercules) of the Greek mythological hero
Heracles. Hercules has no first magnitude stars. Mu Herculis is
27.4 light years from Earth. The solar apex, i.e., the point on
the sky which marks the direction that the Sun is moving in its
orbit around the center of the Milky Way, is located within
Hercules, close to Vega in neighboring Lyra. Notable deep sky
objects Hercules contains two of the most conspicuous globular
clusters: M13, the brightest globular cluster in the northern
hemisphere, and M92. The hero's head is traced by a quadrangle
of stars: π Her, η Her, ζ Her and ε Her known as the "Keystone"
asterism. This quadrangle lies between two very bright stars:
Vega in the constellation Lyra and α CrB (Gemma, or Alphecca) in
the constellation Corona Borealis. He is the great warrior of
Kiaish. The hero's right leg contains two bright stars of the
third magnitude: α H