Thuban, also designated Alpha Draconis (α Draconis, abbreviated Alpha Dra, α Dra), is a star (or star system) in the constellation of Draco, a blue-white giant star of magnitude 3.7, 309 light-years from Earth. It is a relatively inconspicuous star in the night sky of the Northern Hemisphere. This used to be the old ‘pole star’ – the north pole star from the 4th to 2nd millennium BC.
Thuban (α Draconis) was the northern pole star from 3942 BC, when it moved farther north than Theta Boötis, until 1793 BC. This is historically significant because the Egyptian pyramids were designed to have one side facing north, with an entrance passage designed so that Thuban would be visible at night. Due to the effects of ‘precession’, it will once again be the pole star around the year 21000 AD.
The traditional name of Alpha Draconis, Thuban, means “head of the serpent” – the term ‘serpent’ also used in connection with the Ancient Egyptian crocodile god Sobek. Thuban is derived from the Arabic Arabic: ثعبان thuʿbān ‘snake’. It is sometimes known as the Dragon’s Tail and as Adib. The emergence of Draco as Pole Star some 5000 years ago, coincides with the development of astrology/astronomy according to the Sumerians.
Thuban made a better pole star than our modern Polaris. Various sources claim that Thuban almost exactly pinpointed the position of the north celestial pole in the year 2787 B.C.. The Harris Magical Papyrus speaks of a cosmic upheaval of fire and water when ‘the south becomes north, and the earth turns over.’