Designations
- Bayer: β Dra
- Flamsteed: 23 Dra
- Hipparchos: HIP 85670
Data
- Constellation: Draco
- Apparent Magnitude: 2.81
- Right Ascension (J2000): 17h30m27.55s
- Declination (J2000): +52°18'18".2
- Colour Index (B-V): 0.98
- Distance: 365.65±8.20ly
Description
Rastaban is one of the two bright stars of the head of Draco, also known as the Lozenge. Various star charts usually depict it as the eye of Draco, in accordance with Ptolemy's description.
Nomenclature
Rastaban
The scientific Arabian term for γ Dra was Ra’s al-Tinnīn, 'head of the sea serpent'. The name was corrupted into Latin into various forms, such as the Renaissance term Rastaben. This form was respelt and misapplied to the star β Dra in modern times.
Alwaid
The indigenous Arabian asterism al-ʽAwā’iḏ, 'the mother camels', was composed of the stars of the Lozenge and of Alrakis (μ Dra). The asterism protrayed a caravan of mother camels protecting their foal, represented by Alruba (HIP 86782), from a pair of wolves, represented by Aldhibah (ζ), and Athebyne (η) Dra. The bastardisation Alwaid was applied as a star name to β Dra in modern times.