Xi Cephei (ξ Cephei, abbreviated Xi Cep, ξ Cep) is a multiple star system in the constellation of Cepheus.
It is approximately 86 light-years from Earth.
It consists of two binary stars, designated Xi Cephei A and B, together with a more distant companion, Xi Cephei C. A's two components are themselves designated Xi Cephei Aa (officially named Kurhah , the traditional name of the system) and Ab.
Nomenclature
ξ Cephei (Latinised to Xi Cephei) is the system's Bayer designation.
The designations of the three constituents as ξ Cephei A, B and C, and those of A's components - ξ Cephei Aa and Ab - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).
Xi Cephei bore the traditional names Kurhah, Alkirdah or Al Kirduh,Islamic Crescent Project: Star names the name coming from Qazvini who gave Al Ḳurḥaḥ (القرحة al-qurhah), an Arabic word Ideler translated as a white spot, or blaze, in the face of a horse.
Allen indicates that Ideler felt this was not a proper name for a star, and suggested the name Al Ḳirdah (ألقردة al qírada "the Ape").
In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars.
The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.
It approved the name Kurhah for the component Xi Cephei Aa on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.
In Chinese,  (), meaning Celestial Hook, refers to an asterism consisting of Xi Cephei, 4 Cephei, HD 194298, Eta Cephei, Theta Cephei, Alpha Cephei, 26 Cephei, Iota Cephei and Omicron Cephei. 中國星座神話
, written by 陳久金.
Published by 台灣書房出版有限公司, 2005, .
Consequently, the Chinese name for Xi Cephei itself is  (, ). 香港太空館
- 研究資源 - 亮星中英對照表 , Hong Kong Space Museum.
Accessed on line November 23, 2010.
Properties
Xi Cephei A is a double-lined spectroscopic binary system with an orbital period of 810.9 days and an eccentricity of 0.46.
The primary, component Aa, is a chemically peculiar Am star, a probable subgiant with an apparent magnitude of +4.29.
Eight arcseconds away, Xi Cephei B is another spectroscopic binary.
Xi Cephei C is a 13th magnitude star nearly two arcminutes away.
References
