Designations
- Bayer: α Dra
- Flamsteed: 11 Dra
- Hipparchos: HIP 68756
Data
- Constellation: Draco
- Apparent Magnitude: 3.68
- Right Ascension (J2000): 14h04m23.03s
- Declination (J2000): +64°22'53".2
- Colour Index (B-V): -0.04
- Distance: 260.51±4.16ly
Description
Thuban is a rather dim star far down the spine of the Serpent. Desite this, it is rather notable for being labelled α. This mislabelling occurred do to a mistake from Tycho, who catalogued the star as second magnitude. Bayer, who gave Greek-letter designations to many stars, did not check Tycho's work and assumed that Thuban was the brightest star of Draco. Thus, the designation α fell upon it. It is also rather notable for being the polestar of 2800BC. It had a closer approach than Polaris ever will at 0.1°.
Nomenclature
Thuban
The name is from the sci-Arab term for γ Dra, Ra’s al-Tinnīn, 'head of the sea serpent'. The name was corrupted into Latin into various forms, such as the Renaissance term Rastaben. The Latin corruption was then misattributed to Arabic thuʽbān, 'serpent', of similar meaning to the original but of the wrong form. The misattribution was then transliterated into Latin and eventually misapplied as a star name for α Dra (see also Rastaban (β Dra)).
Adib
This name comes from the ind-Arab term al-Ḏi’b al-Awwal, 'the first wolf' for ζ Dra (see Aldhibah). The name was first misapplied to the nearby star θ Dra and then was misapplied again to α Dra.
Sources
- IAU WGSN. IAU-Catalog of Star Names (CSN). link.
- Stellarium Contributors. Stellarium Astronomy Software. link.
- Ridpath, Ian. Star Tales. link.
- Kunitszch, Paul. Smart, Tim. A Dictionary of Modern Star Names (2006), pp. 34. link.
- Lafitte, Roland. Catalogue of Star Names Created in the Greco-Arabian Sky. link.