Xi Draconis
{{Short description|Star in the constellation Draco}}
{{Starbox begin
| name = Xi Draconis
}}
{{Starbox image
| image = 300px
| caption = ξ Draconis in optical light
}}
{{Starbox observe
| epoch = J2000
| constell = Draco
| dec = {{DEC|+56|52|21.5143}}
}}
{{Starbox character
| variable =
}}
{{Starbox astrometry
| prop_mo_ra = {{nowrap|93.82 ± 0.14}}
| prop_mo_dec = {{nowrap|78.50 ± 0.12}}
| parallax = 28.98
| p_error = 0.12
}}
{{Starbox detail
| luminosity = {{Val|47.30|0.44}}
| temperature = {{Val|4451|7|fmt=commas}}
}}
{{Starbox catalog
| names = 32 Dra, BD+56 2033, FK5 671, HD 163588, HIP 87585, HR 6688, SAO 30631, WDS 17535+5652.
}}
{{Starbox reference
|Simbad=ksi+Dra
}}
{{Starbox end}}
Xi Draconis (ξ Draconis, abbreviated Xi Dra, ξ Dra) is a double or binary star in the northern circumpolar constellation of Draco. It has an apparent visual magnitude of 3.75. Based upon parallax measurements, it is located at a distance of {{Convert|112.5|ly|pc|abbr=off|lk=on}} from the Sun. At this distance, the apparent magnitude is diminished by 0.03 from extinction caused by intervening gas and dust.
The two components are designated Xi Draconis A (officially named Grumium {{IPAc-en|'|g|r|uː|m|i|@|m}}, a traditional name for the system){{cite book
|last1=Kunitzsch |first1=Paul
|last2=Smart |first2=Tim
|date = 2006 |edition = 2nd rev.
|title = A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations
|publisher = Sky Pub |location = Cambridge, Massachusetts
|isbn = 978-1-931559-44-7
Nomenclature
ξ Draconis (Latinised to Xi Draconis) is the system's Bayer designation. The designations of the two components as Xi Draconis A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).{{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. }}
It bore the traditional names Grumium. This is a graphic corruption of the Latin Grunnum 'snout',In medieval manuscripts, both 'nn' and 'mi' were written with four strokes, ıııı, and thus could be easily confused. (That is why we now dot our i's.) Indeed, both the correct and corrupted spellings would have looked rather like Grııııııııııı. as Ptolemy had described this star as being on the jawbone of the dragon. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN){{citation
| url=https://www.iau.org/science/scientific_bodies/working_groups/280/
| title=IAU Working Group on Star Names (WGSN)
| publisher=International Astronomical Union
| access-date=22 May 2016 | postscript=. }} to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.{{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 |access-date=2018-07-14}} It approved the name Grumium for the component Xi Draconis A on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.
This star was also known as Nodus I or Nodus Primus. Along with Beta Draconis (Rastaban), Gamma Draconis (Eltanin), Mu Draconis (Erakis) and Nu Draconis (Kuma), it was one of Al ʽAwāyd "the Mother Camels", which were later known as the Quinque Dromedarii.
In Chinese, {{lang|zh|天棓}} ({{lang|zh-Latn|Tiān Bàng}}), meaning Celestial Flail, refers to an asterism consisting of Xi Draconis, Nu Draconis, Beta Draconis, Gamma Draconis and Iota Herculis.{{in lang|zh}} 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}}. Consequently, the Chinese name for Xi Draconis itself is {{lang|zh|天棓一}} ({{lang|zh-Latn|Tiān Bàng yī}}, {{langx|en|the First Star of Celestial Flail}}).{{in lang|zh}} [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_e_g.htm 香港太空館 - 研究資源 - 亮星中英對照表] {{webarchive |url=https://web.archive.org/web/20110130063007/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_e_g.htm |date=January 30, 2011 }}, Hong Kong Space Museum. Accessed on line November 23, 2010.
=Namesake=
USS Grumium (AK-112) was a United States Navy Crater-class cargo ship named after the star.
Properties
Xi Draconis A is of spectral class K2-III. It is not known for certain if Xi Draconis A is on the red giant branch, fusing hydrogen into helium in a shell surrounding an inert helium core, or on the horizontal branch fusing helium into carbon. The possible companion, Xi Draconis B, is a 16th-magnitude star 316 arcseconds away but, most likely, the pairing is just a line-of-sight coincidence.{{citation | first1=James B. | last1=Kaler | work=Stars | publisher=University of Illinois | title=GRUMIUM (Xi Draconis) | url=http://stars.astro.illinois.edu/sow/grumium.html | access-date=2018-02-14 }}
References
{{reflist|refs=
| title=Mg II chromospheric radiative loss rates in cool active and quiet stars
| last1=Cardini | first1=D. | postscript=.
| journal=Astronomy and Astrophysics
| volume=430 | pages=303–311 | date=January 2005
| doi=10.1051/0004-6361:20041440 | bibcode=2005A&A...430..303C |arxiv = astro-ph/0409683 | s2cid=12136256 }}
{{citation | last1=Jennens | first1=P. A. | last2=Helfer | first2=H. L. | title=A new photometric metal abundance and luminosity calibration for field G and K giants. | journal=Monthly Notices of the Royal Astronomical Society | volume=172 | pages=667–679 |date=September 1975 | issue=3 | bibcode=1975MNRAS.172..667J | postscript=. | doi=10.1093/mnras/172.3.667| doi-access=free }}
}}
{{Stars of Draco}}
{{Authority control}}
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