}}{{Starbox astrometry
| radial_v =
| prop_mo_ra = {{Val|215.46|1.14}}[1]
| prop_mo_dec = {{Val|91.06|0.97}}[1]
| parallax = 38.10
| p_error = 2.81
| parallax_footnote = [9]
| absmag_v = +1.79[10]
}}{{Starbox orbit
| reference = [11]
| period_unitless = 810.9 d
| eccentricity = 0.46
| periastron = 2438529.8 JD
| periarg = 106
| k1 = 7.1
| k2 = 19.9
}}{{Starbox detail
| component1 = ξ Cephei Aa
| mass = {{Val|1.045|0.031}}[9]
| luminosity =
| component2 = ξ Cephei Ab
| mass2 = {{Val|0.408|0.066}}[9]
}}{{Starbox catalog
| names = Kurhah, 17 Cephei, BD+63°1802, CCDM J22038+2407, HIP 108917, HR 8417, SAO 19827, WDS J22038+6438
| component1 = A
| names1 = HD 209790
| component2 = B
| names2 = HD 209791
}}{{Starbox reference
| Simbad = HR+8417 |sn=ξ
| Simbad2 = HD+209790 |sn2=A
| Simbad3 = HD+209791 |sn3=B
}}{{Starbox end}}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.[9]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 (also named Kurhah[1]) 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).[2]Xi Cephei bore the traditional names Kurhah, Alkirdah or Al Kirduh,[3] 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").[4] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[5] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[6] 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.[1]
In Chinese, {{lang|zh|天鈎}} ({{lang|zh-Latn|Tiān Gōu}}), 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.[7] Consequently, Xi Cephei itself is known as {{lang|zh|天鈎六}} ({{lang|zh-Latn|Tiān Gōu liù}}, {{lang-en|the Sixth Star of Celestial Hook}}).[8]
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.[11] 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.[4]
References
1. ^1 {{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars |publisher=IAU.org |accessdate=16 December 2017}}
2. ^{{cite arXiv |title=On the naming convention used for multiple star systems and extrasolar planets |date=2010 |eprint=1012.0707 |class=astro-ph.SR |last1= Hessman |first1=F. V. |last2= Dhillon |first2=V. S. |last3= Winget |first3=D. E. |last4= Schreiber |first4=M. R. |last5= Horne |first5=K. |last6= Marsh |first6=T. R. |last7= Guenther |first7=E. |last8= Schwope |first8=A. |last9= Heber |first9=U. }}
3. ^Islamic Crescent Project: Star names
4. ^{{cite book | last=Allen | first=R. H. | year=1963 | authorlink=Richard Hinckley Allen | title=Star Names: Their Lore and Meaning | url=http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Cepheus*.html | accessdate=2010-12-12 | edition=Reprint | publisher=Dover Publications Inc | location=New York | isbn=0-486-21079-0 | page=159 }}
5. ^{{citation | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN) | publisher=International Astronomical Union | accessdate=22 May 2016 | postscript=. }}
6. ^{{cite web | url=https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf | page=5 | title=WG Triennial Report (2015-2018) - Star Names |accessdate=2018-07-14}}
7. ^{{zh icon}} 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, {{ISBN|978-986-7332-25-7}}.
8. ^{{zh icon}} 香港太空館 - 研究資源 - 亮星中英對照表 {{webarchive |url=https://web.archive.org/web/20110129031951/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_h_l.htm |date=January 29, 2011 }}, Hong Kong Space Museum. Accessed on line November 23, 2010.
9. ^1 {{cite journal | doi=10.1086/191315 | bibcode=1989ApJS...69..301G| title=The early F-type stars - Refined classification, confrontation with Stromgren photometry, and the effects of rotation| journal=The Astrophysical Journal Supplement Series| volume=69| pages=301| year=1989| last1=Gray| first1=R. O| last2=Garrison| first2=R. F}}
10. ^1 2 {{citation | title=SB9: The ninth catalogue of spectroscopic binary orbits | journal=Astronomy & Astrophysics |display-authors=5 | last1=Pourbaix | first1=D. | last2=Tokovinin | first2=A. A. | last3=Batten | first3=A. H. | last4=Fekel | first4=F. C. | last5=Hartkopf | first5=W. I. | last6=Levato | first6=H. | last7=Morrell | first7=N. I. | last8=Torres | first8=G. | last9=Udry | first9=S. | volume=424 | issue=2 | pages=727 | date=2004 | doi=10.1051/0004-6361:20041213 | bibcode=2004A&A...424..727P | arxiv=astro-ph/0406573 | postscript=. }}
11. ^1 {{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | postscript=. }}
12. ^1 2 3 4 {{cite journal|title=Separated Fringe Packet Observations with the CHARA Array. II. omega Andromeda, HD 178911, and xi Cephei |last1=Farrington |first1=C. D. |last2=ten Brummelaar |first2=T. A. |last3=Mason |first3=B. D. |last4=Hartkopf |first4=W. I. |last5=Mourard |first5=D. |last6=Moravveji |first6=E. |last7=McAlister |first7=H. A. |last8=Turner |first8=N. H. |last9=Sturmann |first9=L. |last10=Sturmann |first10=J. |displayauthors=1 |journal=The Astronomical Journal |volume=148 |issue=3 |pages=48 |year=2014 |arxiv=1407.0639 |bibcode=2014AJ....148...48F |doi=10.1088/0004-6256/148/3/48 }}
13. ^1 2 3 4 {{cite journal | title=Validation of the new Hipparcos reduction | url=http://www.aanda.org/articles/aa/full/2007/41/aa8357-07/aa8357-07.html | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 }}Vizier catalog entry
14. ^1 {{cite journal|bibcode= 2003AJ....125..984M |title= The USNO-B Catalog |journal= The Astronomical Journal |volume= 125 |issue= 2 |pages= 984 |author1= Monet |first1= David G. |last2= Levine |first2= Stephen E. |last3= Canzian |first3= Blaise |last4= Ables |first4= Harold D. |last5= Bird |first5= Alan R. |last6= Dahn |first6= Conard C. |last7= Guetter |first7= Harry H. |last8= Harris |first8= Hugh C. |last9= Henden |first9= Arne A. |last10= Leggett |first10= Sandy K. |last11= Levison |first11= Harold F. |last12= Luginbuhl |first12= Christian B. |last13= Martini |first13= Joan |last14= Monet |first14= Alice K. B. |last15= Munn |first15= Jeffrey A. |last16= Pier |first16= Jeffrey R. |last17= Rhodes |first17= Albert R. |last18= Riepe |first18= Betty |last19= Sell |first19= Stephen |last20= Stone |first20= Ronald C. |last21= Vrba |first21= Frederick J. |last22= Walker |first22= Richard L. |last23= Westerhout |first23= Gart |last24= Brucato |first24= Robert J. |last25= Reid |first25= I. Neill |last26= Schoening |first26= William |last27= Hartley |first27= M. |last28= Read |first28= M. A. |last29= Tritton |first29= S. B. |year= 2003 |doi= 10.1086/345888 |arxiv = astro-ph/0210694 }}
15. ^1 2 {{cite journal|bibcode=2001AJ....122.3466M|title=The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog|journal=The Astronomical Journal|volume=122|issue=6|pages=3466|author1=Mason|first1=Brian D.|last2=Wycoff|first2=Gary L.|last3=Hartkopf|first3=William I.|last4=Douglass|first4=Geoffrey G.|last5=Worley|first5=Charles E.|year=2001|doi=10.1086/323920}}