Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar (never setting) for many observers in the Northern Hemisphere. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations today. The brightest star in Draco is Gamma Draconis, traditionally called Etamin or Eltanin. It is an orange giant star of magnitude 2.2, 148 light-years from Earth. The other curious star is Thuban (a Draconis), magnitude 3.7, 309 light-years from Earth. It was the northern pole star from 3942 BC until 1793 BC. Due to the effects of precession, it will once again be the pole star around the year 21000 AD. One of the deep-sky objects in Draco is the Cat's Eye Nebula (NGC 6543), a planetary nebula approximately 3,000 light-years away. It is 9th magnitude and was named for its appearance in the Hubble Space Telescope, though it appears as a fuzzy blue-green disk in an amateur telescope.
