Lyra, or The Harp, a constellation in the Northern Hemisphere, between Hercules and Cygnus. In mythology, it represents the lyre of Orpheus or Mercury. The constellation's brightest star is Alpha Lyrae, or Vega, the fifth brightest star in the night sky as seen from the earth. Lyra contains a double-double star, Epsilon Lyrae, and a well-known planetary nebula, the Ring Nebula.