{{Short description|Star in the constellation Draco}} {{Starbox begin}} {{Starbox image | image = {{Location mark |image=Draco constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=ξ Draconis |x=245|y=850 }} | caption = Location of ξ Draconis (circled in red) }} {{Starbox observe | epoch = J2000 | constell = [[Draco (constellation)|Draco]] | ra = {{RA|17|53|31.72962}}<ref name=aaa474_2_653/> | dec = {{DEC|+56|52|21.5143}}<ref name=aaa474_2_653/> | appmag_v = 3.75<ref name=mnras172_667/> }} {{Starbox character | class = K2 III<ref name=araa11_29/> | b-v = +1.18<ref name=mnras172_667/> | u-b = +1.21<ref name=mnras172_667/> | variable = }} {{Starbox astrometry | radial_v = −26.38 ± 0.20<ref name=aaa430_165/> | prop_mo_ra = {{nowrap|93.82 ± 0.14}}<ref name=aaa474_2_653/> | prop_mo_dec = {{nowrap|78.50 ± 0.12}}<ref name=aaa474_2_653/> | parallax = 28.98 | p_error = 0.12 | parallax_footnote = <ref name=aaa474_2_653/> | absmag_v = +1.06<ref name=Cardini2005/> }} {{Starbox detail | mass = 1.45 ± 0.17<ref name=apjl674_1_L53/> | radius = {{val|11.56|0.06}}<ref name=Baines2014/> | luminosity = {{Val|47.30|0.44}}<ref name=Baines2014/> | temperature = {{Val|4451|7|fmt=commas}}<ref name=Baines2014/> | gravity = 2.3<ref name=aj135_1_209/> | metal_fe = −0.09<ref name=aj135_1_209/> | rotational_velocity = 2.3<ref name=aj135_1_209/> }} {{Starbox catalog | names = {{odlist | name=Grumium | B=ξ Dra | F=32 Dra | BD=+56 2033 | FK5=671 | HD=163588 | HIP=87585 | HR=6688 | SAO=30631 | WDS=J17535+5652}} }} {{Starbox reference |Simbad=ksi+Dra }} {{Starbox end}}
'''Xi Draconis''' ('''ξ Draconis''', abbreviated '''Xi Dra''', '''ξ Dra''') is a [[double star|double]] or [[binary star]] in the [[Northern celestial hemisphere|northern]] [[circumpolar constellation]] of [[Draco (constellation)|Draco]]. It has an [[apparent visual magnitude]] of 3.75.<ref name=mnras172_667/> Based upon [[stellar parallax|parallax]] measurements, it is located at a distance of {{Convert|112.5|ly|pc|abbr=off|lk=on}} from the [[Sun]].<ref name=aaa474_2_653/> At this distance, the apparent magnitude is diminished by 0.03 from [[extinction (astronomy)|extinction]] caused by intervening gas and dust.<ref name=aaa430_165/>
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)<ref name=Kunitzsch>{{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 }}</ref><ref name="IAU-LSN">{{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars | publisher=IAU.org | access-date=16 December 2017 | archive-date=11 April 2020 | archive-url=https://web.archive.org/web/20200411104839/https://www.iau.org/public/themes/naming_stars/ | url-status=dead }}</ref> and B.
==Nomenclature== [[File:Xi Draconis.jpg|thumb|left|300px|ξ Draconis in optical light]] ''ξ Draconis'' ([[Latinisation of names|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 system]]s, and adopted by the [[International Astronomical Union]] (IAU).<ref name="planetnaming">{{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. }}</ref>
It bore the traditional names ''Grumium''. This is a graphic corruption of the Latin ''Grunnum'' 'snout',<ref>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''.</ref> as Ptolemy had described this star as being on the jawbone of the dragon.<ref name=Kunitzsch/> In 2016, the [[International Astronomical Union]] organized a [[Working Group on Star Names]] (WGSN)<ref name="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=. | archive-date=10 June 2016 | archive-url=https://web.archive.org/web/20160610172014/https://www.iau.org/science/scientific_bodies/working_groups/280/ | url-status=dead }}</ref> to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire [[Star system|multiple systems]].<ref name="TriRpt18">{{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 | archive-date=2022-10-09 | archive-url=https://ghostarchive.org/archive/20221009/https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf | url-status=dead }}</ref> 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.<ref name="IAU-LSN"/>
This star was also known as ''Nodus I'' or ''Nodus Primus''. Along with [[Beta Draconis]] (Rastaban), [[Gamma Draconis]] (Eltanin), [[Mu Draconis]] (Alrakis) and [[Nu Draconis]] (Kuma), it was one of ''Al ʽAwāyd'' "the Mother Camels", which were later known as the ''Quinque Dromedarii''.<ref name=allen1963/>
In [[Chinese astronomy|Chinese]], {{lang|zh|天棓}} ({{lang|zh-Latn|Tiān Bàng}}), meaning ''[[Purple Forbidden enclosure|Celestial Flail]]'', refers to an [[Asterism (astronomy)|asterism]] consisting of Xi Draconis, Nu Draconis, Beta Draconis, Gamma Draconis and [[Iota Herculis]].<ref>{{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}}.</ref> Consequently, the [[Chinese star names|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}}).<ref>{{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.</ref>
===Namesake=== [[USS Grumium (AK-112)|USS ''Grumium'' (AK-112)]] was a [[United States Navy]] [[Crater-class cargo ship|''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.<ref name="kalerAC" /> The possible companion, Xi Draconis B, is a 16th-magnitude star 316 [[arcseconds]] away. [[Jim Kaler]] in 2008 said that most likely, the pairing is just a line-of-sight coincidence,<ref name="kalerAC">{{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 }}</ref> but [[Gaia DR3]] data shows a similar parallax and proper motion to the primary.<ref>{{cite simbad |title=LP 102-432}}</ref>
==References== <references> <ref name=aaa474_2_653>{{citation | first=F. | last=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | postscript=. |arxiv = 0708.1752 | s2cid=18759600 }}</ref>
<ref name=Cardini2005>{{citation | 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 }}</ref>
<ref name=Baines2014>{{Citation |last=Baines |first=Ellyn K. |last2=Armstrong |first2=J. Thomas |last3=Schmitt |first3=Henrique R. |last4=Benson |first4=James A. |last5=Zavala |first5=R. T. |last6=van Belle |first6=Gerard T. |date=2014-01-13 |title=Navy Precision Optical Interferometer Measurements of 10 Stellar Oscillators |journal=The Astrophysical Journal |volume=781 |issue=2 |pages=90 |doi=10.1088/0004-637x/781/2/90 |bibcode=2014ApJ...781...90B |issn=0004-637X|arxiv=1401.3342 }}</ref>
<ref name=apjl674_1_L53>{{citation | display-authors=1 | last1=Stello | first1=D. | last2=Bruntt | first2=H. | last3=Preston | first3=H. | last4=Buzasi | first4=D. | title=Oscillating K Giants with the WIRE Satellite: Determination of Their Asteroseismic Masses | journal=The Astrophysical Journal Letters | volume=674 | issue=1 | year=2008 | pages=L53–L56 | doi=10.1086/528936 | bibcode=2008ApJ...674L..53S | postscript=. |arxiv = 0801.2155 | s2cid=15094067 }}</ref>
<ref name=aj135_1_209>{{citation | display-authors=1 | last1=Massarotti | first1=Alessandro | last2=Latham | first2=David W. | last3=Stefanik | first3=Robert P. | last4=Fogel | first4=Jeffrey | title=Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity | journal=The Astronomical Journal | volume=135 | issue=1 | pages=209–231 |date=January 2008 | doi=10.1088/0004-6256/135/1/209 | bibcode=2008AJ....135..209M | s2cid=121883397 | postscript=. | doi-access=free }}</ref>
<ref name=aaa430_165>{{citation | display-authors=1 | last1=Famaey | first1=B. | last2=Jorissen | first2=A. | last3=Luri | first3=X. | last4=Mayor | first4=M. | last5=Udry | first5=S. | last6=Dejonghe | first6=H. | last7=Turon | first7=C. | title=Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters | journal=Astronomy and Astrophysics | volume=430 | issue=1 | pages=165–186 |date=January 2005 | doi=10.1051/0004-6361:20041272 | bibcode=2005A&A...430..165F |arxiv = astro-ph/0409579 | s2cid=17804304 | postscript=. }}</ref>
<ref name=mnras172_667>{{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 }}</ref>
<ref name=allen1963>{{citation | last=Allen | first=R. H. | year=1963 | author-link=Richard Hinckley Allen | title=Star Names: Their Lore and Meaning | url=https://archive.org/details/starnamestheirlo00alle/page/207 | access-date=2010-12-12 | edition=Reprint | publisher=Dover Publications Inc. | location=New York, NY | isbn=0-486-21079-0 | page=[https://archive.org/details/starnamestheirlo00alle/page/207 207] | postscript=. | url-access=registration }}</ref>
<ref name=araa11_29>{{citation | last1=Morgan | first1=W. W. | last2=Keenan | first2=P. C. | title=Spectral Classification | journal=Annual Review of Astronomy and Astrophysics | volume=11 | pages=29–50 | year=1973 | doi=10.1146/annurev.aa.11.090173.000333 | bibcode=1973ARA&A..11...29M | postscript=. }}</ref> </references>
{{Stars of Draco}}
{{Authority control}}
[[Category:Draco (constellation)]] [[Category:Bayer objects|Draconis, Xi]] [[Category:Stars with proper names|Grumium]] [[Category:K-type giants]] [[Category:Hipparcos objects|087585]] [[Category:Flamsteed objects|Draconis, 32]] [[Category:Bright Star Catalogue objects|6688]] [[Category:Henry Draper Catalogue objects|163588]] [[Category:Durchmusterung objects|BD+56 2033]]