View source for Astronomy:Mu1 Scorpii

{{short description|Binary star system in the constellation Scorpius}}
{{DISPLAYTITLE:Mu<sup>1</sup> Scorpii}}
{{other stars by Bayer designation|μ Scorpii}}
{{Starbox begin
 | name = μ<sup>1</sup> Scorpii
}}
{{Starbox image
 | image=
{{Location mark
|image=Scorpius constellation map.svg|alt=|float=center|width=260
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=μ<sup>1</sup> Sco
|x=476|y=724
}}
|caption=Location of μ<sup>1</sup> Scorpii (circled)
}}
{{Starbox observe 
 | epoch       = J2000 
 | ra          = {{RA|16|51|52.23111}}<ref name=aaa474_2_653/>
 | dec         = {{DEC|-38|02|50.5694}}<ref name=aaa474_2_653/>
 | appmag_v    = 2.94 - 3.22<ref name=gcvs/>
 | constell    = Scorpius
}}
{{Starbox character 
 | class       = {{nowrap|B1.5 V + B6.5 V}}<ref name=mnras401_3_2059/>
 | b-v         = −0.202<ref name=apjs15_459/>
 | u-b         = −0.859<ref name=apjs15_459/>
 | variable    = [[Astronomy:Beta Lyrae variable|β Lyr]]<ref name=gcvs/>
}}
{{Starbox astrometry 
 | radial_v    = −25<ref name=gcsrv/>
 | prop_mo_ra  = −10.58<ref name=aaa474_2_653/> 
 | prop_mo_dec = −22.06<ref name=aaa474_2_653/> 
 | parallax    = 6.51
 | p_error     = 0.91
 | parallax_footnote = <ref name=aaa474_2_653/>
 | absmag_v    = {{val|−2.9|0.3}}<ref name=mnras401_3_2059/>
}}
{{Starbox orbit
 | reference = <ref name=mnras401_3_2059/>
 | period_unitless = 1.44627&nbsp;days
 | axis_unitless = {{Solar radius|{{val|12.90|0.04}}}}
 | eccentricity = 0.0
 | inclination = {{val|65.4|1}}
 | node = <!--Longitude of node (in degrees)-->
 | periastron = 2412374.434&nbsp;[[Astronomy:Heliocentric Julian Day|HJD]]
 | periarg = <!--Argument of periastron (in degrees), secondary -->
 | periarg_primary = <!--Argument of periastron (in degrees), primary -->
}}
{{Starbox detail
 | source = <ref name=budding2015/>
 | component1  = μ<sup>1</sup> Sco A
 | mass        = {{val|8.3|1.0}}
 | radius      = {{val|3.9|0.2}}
 | gravity     = {{val|4.17|0.10}}
 | metal_fe    = 
 | rotation    = 
 | age_myr     = 
 | luminosity  = 
 | temperature = {{val|24000|1000|fmt=commas}}
 | rotational_velocity = 191.5
 | component2  = μ<sup>1</sup> Sco B
 | mass2       = {{val|4.6|1.0}}
 | radius2     = {{val|4.6|0.3}}
 | temperature2= {{val|17000|700|fmt=commas}}
 | gravity2    = {{val|3.77|0.12}}
 | rotational_velocity2 = 165.0
}}
{{Starbox catalog
 | names = Xamidimura, CD−37°11033, FK5&nbsp;1439, HD&nbsp;151890, HIP&nbsp;82514, HR&nbsp;6247, SAO&nbsp;208102, [[Astronomy:Washington Double Star Catalog|WDS]] 16519-3803
}}
{{Starbox reference
|Simbad=mu01+Sco
}}
{{Starbox end}}

'''Mu<sup>1</sup> Scorpii''' ('''μ<sup>1</sup> Scorpii''', abbreviated '''Mu<sup>1</sup> Sco''', '''μ<sup>1</sup> Sco''') is a [[Astronomy:Binary star|binary star]] system in the southern [[Astronomy:Zodiac|zodiac]] [[Astronomy:Constellation|constellation]] of [[Astronomy:Scorpius|Scorpius]]. The combined [[Astronomy:Apparent magnitude|apparent visual magnitude]] of the pair is about magnitude 3, making it one of the [[Astronomy:List of stars in Scorpius|brighter members]] of Scorpius. Based upon [[Astronomy:Parallax|parallax]] measurements, the distance of this system from the [[Astronomy:Sun|Sun]] is roughly 500&nbsp;[[Astronomy:Light-year|light-year]]s (150&nbsp;[[Astronomy:Parsec|parsec]]s).<ref name=aaa474_2_653/> This system is a member of the [[Astronomy:Scorpius–Centaurus association|Scorpius–Centaurus association]], the nearest OB association of co-moving stars to the Sun.<ref name=mnras401_3_2059/>

The primary (Mu<sup>1</sup> Scorpii Aa) is formally named '''Xamidimura''' {{IPAc-en|,|k|æ|m|i|d|i|'|m|ʊər|@}}, from the Khoekhoe ''xami di mûra'' {{IPA-all|xami ti mũːɾa}} 'the (two) eyes of the lion'.<ref name="IAU-LSN"/>

== Properties ==
[[File:Mu1ScoLightCurve.png|thumb|left|A [[Astronomy:Light curve|light curve]] for Mu<sup>1</sup> Scorpii, plotted from ''TESS'' data<ref name=MAST/>]]
Mu<sup>1</sup> Scorpii is an [[Astronomy:Binary star#Eclipsing binaries|eclipsing binary]] of the [[Astronomy:Beta Lyrae variable|Beta Lyrae type]]. Discovered to be a [[Astronomy:Binary star#Spectroscopic binaries|spectroscopic binary]] by [[Biography:Solon Irving Bailey|Solon Irving Bailey]] in 1896, it was only the third such eclipsing pair to be discovered. This is a [[Astronomy:Binary star#Configuration of the system|semidetached binary]] system where the secondary is close to filling its [[Physics:Roche lobe|Roche lobe]], or it may even be overflowing. The two stars revolve each other along a circular orbit with the components separated by 12.9 times the [[Astronomy:Solar radius|Sun's radius]].<ref name=mnras401_3_2059/> Due to occultation of each component by the other, the apparent magnitude of the system decreased by 0.3 and 0.4 magnitudes over the course of the binary's orbit, which takes 34 hours 42.6 minutes to complete.

The primary component is a [[Astronomy:Stellar classification#Class B|B-type]] [[Astronomy:Main sequence|main sequence]] star with a stellar classification of B1.5&nbsp;V. It has 8.3 times the mass of the Sun and 3.9 times the Sun's radius. The secondary is a smaller B-type main sequence star with a classification of about B6.5&nbsp;V, having 3.6 times the Sun's mass and 4.6 times the radius of the Sun. The [[Astronomy:Effective temperature|effective temperature]] of the [[Astronomy:Stellar atmosphere|outer atmosphere]] for each star is 24,000&nbsp;K for the primary and 17,000&nbsp;K for the secondary. At these temperatures, the two stars glow with a blue-white hue.<ref name=csiro/>

== Nomenclature ==

''μ<sup>1</sup> Scorpii'' ([[Social:Latinisation of names|Latinised]] to ''Mu<sup>1</sup> Scorpii'') is the system's [[Astronomy:Bayer designation|Bayer designation]]. The designations of the primary as ''Mu<sup>1</sup> Scorpii Aa'' derives from the convention used by the Washington Multiplicity Catalog (WMC) for [[Astronomy:Star system|multiple star system]]s, and adopted by the [[Organization:International Astronomical Union|International Astronomical Union]] (IAU).<ref name="planetnaming"/>

The pair of stars Mu<sup>1</sup> and [[Astronomy:Mu2 Scorpii|Mu<sup>2</sup> Scorpii]] are known as the ''xami di mura'' 'eyes of the lion' by the Khoikhoi people of {{wipe|South Africa}}.<ref name=ASSA/>

In 2016, the IAU organized a [[Astronomy:IAU Working Group on Star Names|Working Group on Star Names]] (WGSN)<ref name="WGSN"/> to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.<ref name="TriRpt18"/> It approved the name ''Xamidimura'' for the component Mu<sup>1</sup> Scorpii Aa on 5 September 2017 (along with Pipirima for the partner of Mu<sup>1</sup> Scorpii) and it is now so included in the List of IAU-approved Star Names.<ref name="IAU-LSN"/>

In [[Astronomy:Chinese astronomy|Chinese]], {{lang|zh|尾宿}} ({{lang|zh-Latn|Wěi Xiù}}), meaning ''[[Astronomy:Tail (Chinese constellation)|Tail]]'', refers to an [[Astronomy:Asterism|asterism]] consisting of Mu<sup>1</sup> Scorpii, [[Astronomy:Epsilon Scorpii|Epsilon Scorpii]], [[Astronomy:Zeta1 Scorpii|Zeta<sup>1</sup> Scorpii]] and [[Astronomy:Zeta2 Scorpii|Zeta<sup>2</sup> Scorpii]], [[Astronomy:Eta Scorpii|Eta Scorpii]], [[Astronomy:Theta Scorpii|Theta Scorpii]], [[Astronomy:Iota1 Scorpii|Iota<sup>1</sup> Scorpii]] and [[Astronomy:Iota2 Scorpii|Iota<sup>2</sup> Scorpii]], [[Astronomy:Kappa Scorpii|Kappa Scorpii]], [[Astronomy:Lambda Scorpii|Lambda Scorpii]] and [[Astronomy:Upsilon Scorpii|Upsilon Scorpii]].<ref name=zh/> Consequently, the [[Astronomy:Chinese star names|Chinese name]] for Mu<sup>1</sup> Scorpii itself is {{lang|zh|尾宿一}} ({{lang|zh-Latn|Wěi Xiù yī}}), "the First Star of Tail".<ref name=lcsd/>

==References==
{{reflist|refs=

<ref name="IAU-LSN">{{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars |publisher=IAU.org |accessdate=16 December 2017}}</ref>

<ref name=MAST>{{cite web |title=MAST: Barbara A. Mikulski Archive for Space Telescopes |url=https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html |publisher=Space Telescope Science Institute |access-date=8 December 2021}}</ref>

<ref name=aaa474_2_653>{{cite journal | first1=F. | last1=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 |arxiv = 0708.1752 | s2cid=18759600 }}</ref>

<ref name=gcsrv>{{cite journal | last=Wilson | first=Ralph Elmer | date=1953 | title=General Catalogue of Stellar Radial Velocities | journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution of Washington | location=Washington | bibcode=1953GCRV..C......0W }}</ref>

<ref name=apjs15_459>{{cite journal | last1=Gutierrez-Moreno | first1=Adelina | last2=Moreno | first2=Hugo | title=A photometric investigation of the Scorpio-Centaurus association |  journal=Astrophysical Journal Supplement | volume=15 | page=459 |date=June 1968 | bibcode=1968ApJS...15..459G | doi=10.1086/190168 | doi-access=free }}</ref>

<ref name=mnras401_3_2059>{{cite journal | last1=van Antwerpen | first1=C. | last2=Moon | first2=T. | title=New observations and analysis of the bright semidetached eclipsing binary μ1 Sco | journal=[[Organization:Monthly Notices of the Royal Astronomical Society|Monthly Notices of the Royal Astronomical Society]] | volume=401 | issue=3 | pages=2059–2066 |date=January 2010 | doi=10.1111/j.1365-2966.2009.15796.x | bibcode=2010MNRAS.401.2059V |arxiv = 0910.1241 | s2cid=119206034 }}</ref>

<ref name=csiro>{{cite web | title=The Colour of Stars | date=December 21, 2004 | work=Australia Telescope, Outreach and Education | publisher=Commonwealth Scientific and Industrial Research Organisation | url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html | accessdate=2012-01-16 | archive-url=https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html | archive-date=March 18, 2012 | url-status=dead }}</ref>

<ref name=ASSA>Astronomical Society of Southern Africa (2013) [http://assa.saao.ac.za/astronomy-in-south-africa/ethnoastronomy/ African ethnoastronomy]</ref>

<ref name="WGSN">{{cite web | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN)|accessdate=22 May 2016}}</ref>

<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>

<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 |accessdate=2018-07-14}}</ref>

<ref name=zh>{{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>

<ref name=lcsd>{{in lang|zh}} [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm 香港太空館 - 研究資源 - 亮星中英對照表] {{webarchive|url=https://web.archive.org/web/20081025110153/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm |date=2008-10-25 }}, Hong Kong Space Museum. Accessed on line November 23, 2010.</ref>

<ref name=gcvs>{{cite journal
 | display-authors=1 | last1=Samus | first1=N. N.
 | last2=Kazarovets | first2=E. V. | last3=Durlevich | first3=O. V.
 | last4=Kireeva | first4=N. N. | last5=Pastukhova | first5=E. N.
 | title=General Catalogue of Variable Stars
 | version=5.1 | journal=Astronomy Reports
 | year=2017 | volume=61 | issue=1 | pages=80–88
 | bibcode=2017ARep...61...80S  | s2cid=125853869
 | doi=10.1134/S1063772917010085 }}</ref>

<ref name=budding2015>{{cite journal |bibcode=2015MNRAS.448.3784B |title=Absolute parameters of young stars: GG Lup and μ<SUP>1</SUP> Sco |last1=Budding |first1=E. |last2=Butland |first2=R. |last3=Blackford |first3=M. |journal=Monthly Notices of the Royal Astronomical Society |year=2015 |volume=448 |issue=4 |page=3784 |doi=10.1093/mnras/stv234 |arxiv=1502.04360 }}</ref>

}}

{{Stars of Scorpius}}

{{DEFAULTSORT:Mu1 Scorpii}}
[[Category:Bayer objects|Scorpii, Mu1]]
[[Category:Binary stars]]
[[Category:Beta Lyrae variables]]
[[Category:B-type main-sequence stars]]
[[Category:Hipparcos objects|082514]]
[[Category:Durchmusterung objects]]
[[Category:Henry Draper Catalogue objects|151890]]
[[Category:Bright Star Catalogue objects|6247]]

{{Sourceattribution|Mu1 Scorpii}}