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Alpha Draconis, 11 Draconis

Proper NameThuban
Bayer DesignationAlpha Draconis
Flamsteed Number11 Draconis
HR (BSC)5291
Right Ascension14h 4m 23s
Declination+64° 22' 33"
Distance303 light years
93 parsecs
MagnitudeApparent: +3.7
Absolute: -1.2
Spectral ClassA0 White Giant
Optimum VisibilityMay (Usually visible from northern latitudes)
NotesThuban lies close to the path of the northern Precession Circle, so that at times it falls very near the Northern Celestial Pole (t was Earth's northern Pole Star for a period of some 2,000 years ending in about 1900 BCE). It is a binary system, with a dwarf companion star orbiting the primary white giant.

Imagery provided by Aladin sky atlas

Location of Thuban

Though it is a faint star in a sparse region of the sky, Thuban is not difficult to locate. It lies halfway between the 'bowl' of the Little Dipper, and the 'handle' of the Big Dipper.

Though only of magnitude +3.7, and by no means the brightest star in its constellation, Thuban is nonetheless designated Alpha Draconis.


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