The Alrakis system is 88 light-years from Earth. Magnitude 5.6 and 5.7, the two components orbit each other every 670 years. Mu Draconis, traditionally called Alrakis, is a binary star with two white components. Eta Draconis (the proper name is Athebyne ) is a double star with a yellow-hued primary of magnitude 2.8 and a white-hued secondary of magnitude 8.2 located south of the primary. One such massive cluster is Abell 2218, located at a distance of 3 billion light-years (redshift 0.171).ĭraco is home to several double stars and binary stars. Draco also features several interacting galaxies and galaxy clusters. Its name shares a meaning with Thuban, "head of the serpent". Nearby Beta Draconis, traditionally called Rastaban, is a yellow giant star of magnitude 2.8, 362 light-years from Earth. The aberration of starlight was discovered in 1728 when James Bradley observed Gamma Draconis. It is an orange giant star of magnitude 2.2, 148 light-years from Earth. The brighter of the three, and the brightest star in Draco, is Gamma Draconis, traditionally called Etamin or Eltanin. There are three stars above magnitude 3 in Draco. The traditional name of Alpha Draconis, Thuban, means "head of the serpent". It is a blue-white giant star of magnitude 3.7, 309 light-years from Earth. Due to the effects of precession, it will again be the pole star around the year AD 21000. The Egyptian Pyramids were designed to have one side facing north, with an entrance passage geometrically aligned so that Thuban would be visible at night. Thuban (α Draconis) was the northern pole star from 3942 BC, when it moved farther north than Theta Boötis, until 1793 BC.
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