View source for Mu2 Scorpii

{{hatnote|For other star systems with a similar [[Bayer designation]], see [[Mu Scorpii]].}}
{{DISPLAYTITLE:Mu<sup>2</sup> Scorpii}}
{{short description|B-type star in the constellation of Scorpius}}
{{Starbox begin
| name = μ<sup>2</sup> Scorpii<br>(Pipirima)
}}
{{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>2</sup> Sco
|x=476|y=724
}}
|caption=Location of μ<sup>2</sup> Scorpii (circled)
}}
{{Starbox observe
| epoch    = J2000
| constell = [[Scorpius]]
| ra       = {{RA|16|52|20.14532}}<ref name=vanLeeuwen2007/>
| dec      = {{DEC|−38|01|03.1258}}<ref name=vanLeeuwen2007/>
| appmag_v = +3.56<ref name=Gutierrez-Moreno1968/>
}}
{{Starbox character
| class    = B2&nbsp;IV<ref name=Hiltner1969/>
| b-v      = −0.219<ref name=Gutierrez-Moreno1968/>
| u-b      = −0.878<ref name=Gutierrez-Moreno1968/>
| variable =
}}
{{Starbox astrometry
| radial_v = +1.4<ref name=rgcrv/>
| prop_mo_ra  = −11.09<ref name=vanLeeuwen2007/>
| prop_mo_dec = −23.32<ref name=vanLeeuwen2007/>
| parallax = 6.88
| p_error  = 0.12
| parallax_footnote = <ref name=vanLeeuwen2007/>
| absmag_v = −2.25<ref name=Anderson2012/>
}}
{{Starbox detail
| source   =
| mass     = {{Val|8.7|0.2}}<ref name=Tetzlaff2011/>
| radius   = 7.0<ref name=Underhill1979/>
| luminosity = 2,385<ref name=Mcdonald2012/>
| gravity  =
| temperature = 23,113<ref name=Underhill1979/>
| metal_fe =
| rotational_velocity = 58<ref name=Uesugi1970/>
| age_myr  = {{Val|18.5|3.2}}<ref name=Tetzlaff2011/>
}}
{{Starbox catalog
| names = Pipirima, [[Bayer designation|μ<sup>2</sup> Scorpii]], [[Durchmusterung|CD]]−37° 11037, [[Henry Draper catalogue|HD]] 151985, [[Hipparcos catalogue|HIP]]&nbsp;82545, [[Bright Star Catalogue|HR]] 6252, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 208116.<ref name=SIMBAD/>
}}
{{Starbox reference
| Simbad = mu02+Sco
}}
{{Starbox end}}
'''Mu<sup>2</sup> Scorpii''' ('''μ<sup>2</sup> Scorpii''', abbreviated '''Mu<sup>2</sup> Sco''', '''μ<sup>2</sup> Sco'''), also named '''Pipirima''' {{IPAc-en|p|ᵻ|'|p|ɪr|ᵻ|m|ə}}<!--it's "Pipiri ma", so stress on penult of "Pipiri"-->,<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> is a [[star]] in the [[zodiac]] [[constellation]] of [[Scorpius]]. It has an [[Apparent magnitude|apparent visual magnitude]] of +3.56,<ref name=Gutierrez-Moreno1968/> which is bright enough to be seen with the naked eye. Its distance from the [[Sun]] is about 474&nbsp;[[light-year]]s, as determined by [[stellar parallax|parallax]] measurements.<ref name=vanLeeuwen2007/> It is a member of the Upper Centaurus–Lupus subgroup of the [[Scorpius–Centaurus association]].<ref name=Bobylev2007/>
== Properties ==
This is a blue-white, [[Stellar classification#Class B|B-type]] [[subgiant]] star with a [[stellar classification]] of B2&nbsp;IV.<ref name=Hiltner1969/> It has an estimated 7 times the [[solar radius|radius of the Sun]], almost 9 times the [[solar mass|Sun's mass]],<ref name=Tetzlaff2011/> and shines with 2,385 times the [[solar luminosity|Sun's luminosity]].<ref name=Mcdonald2012/> The [[stellar atmosphere|outer atmosphere]] has an [[effective temperature]] of 23,113&nbsp;K.<ref name=Underhill1979/> It is some 18.5<ref name=Tetzlaff2011/>&nbsp;million years old and is spinning with a [[Stellar rotation#Measurement|projected rotational velocity]] of 58&nbsp;km/s.<ref name=Uesugi1970/>
== Nomenclature ==
''μ<sup>2</sup> Scorpii'' ([[Latinisation of names|Latinised]] to ''Mu<sup>2</sup> Scorpii'') is the star's [[Bayer designation]].
In Tahiti, a [[Polynesian narrative|traditional story]] is told of a brother and sister, named ''Pipiri'' and ''Rehua'', who flee their parents into the sky and become stars. Their parents call them ''Pipiri ma'' while chasing them into the sky: ''ma'' "with, and" is used after names to mean "et al."<ref name=Andersen/><ref>Herbert John Davies, ''A Tahitian and English dictionary, with introductory remarks on the Polynesian language, and a short grammar of the Tahitian dialect''. London Missionary Society, 1851.</ref> In one account, the children become [[Shaula]] and [[Lesath]] in the tip of the tail of Scorpio,<ref name=Andersen/> and in another they become Mu<sup>2</sup> and [[Mu1 Scorpii|Mu<sup>1</sup> Scorpii]].{{cn|date=April 2019}} (In a similar version of the story told in the [[Cook Islands]], they become [[Omega Scorpii|Omega<sup>1</sup> and Omega<sup>2</sup> Scorpii]]).<ref name=Andersen>Johannes Carl Andersen (1931) ''Myths and Legends of the Polynesians''. 1995 Dover reprint, p.400''ff''.</ref>
In 2016, the IAU organized a [[IAU Working Group on Star Names|Working Group on Star Names]] (WGSN)<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> to catalog and standardize proper names for stars. The WGSN approved the name ''Pipirima'' for this star on 5 September 2017 (along with [[Xamidimura]] for its partner) and it is now so included in the List of IAU-approved Star Names.<ref name="IAU-LSN"/>
In [[Chinese astronomy]], Mu<sup>2</sup> Scorpii is called 尾宿增二.<ref>{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0605/ap060510.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 10 日] {{Webarchive|url=https://web.archive.org/web/20110522111342/http://aeea.nmns.edu.tw/2006/0605/ap060510.html |date=2011-05-22 }}</ref>
==Planetary system==
Two sub-stellar objects slightly above deuterium burning limit ([[brown dwarf]]s) were found in 2022 by direct imaging near Mu<sup>2</sup> Scorpii. The outer one, designated μ<sup>2</sup> Scorpii b, is definitely an orbiting planet or brown dwarf, and the inner one is a planetary candidate.<ref name=Squicciarini2022>{{citation|arxiv=2205.02279|year=2022|title=A scaled-up planetary system around a supernova progenitor|doi=10.1051/0004-6361/202243675 |last1=Squicciarini |first1=V. |last2=Gratton |first2=R. |last3=Janson |first3=M. |last4=Mamajek |first4=E. E. |last5=Chauvin |first5=G. |last6=Delorme |first6=P. |last7=Langlois |first7=M. |last8=Vigan |first8=A. |last9=Ringqvist |first9=S. C. |last10=Meeus |first10=G. |last11=Reffert |first11=S. |last12=Kenworthy |first12=M. |last13=Meyer |first13=M. R. |last14=Bonnefoy |first14=M. |last15=Bonavita |first15=M. |last16=Mesa |first16=D. |last17=Samland |first17=M. |last18=Desidera |first18=S. |last19=d'Orazi |first19=V. |last20=Engler |first20=N. |last21=Alecian |first21=E. |last22=Miglio |first22=A. |last23=Henning |first23=T. |last24=Quanz |first24=S. P. |last25=Mayer |first25=L. |last26=Flasseur |first26=O. |last27=Marleau |first27=G.-D. |journal=Astronomy & Astrophysics |volume=664 |pages=A9 |bibcode=2022A&A...664A...9S |s2cid=248524983 }}</ref>
{{OrbitboxPlanet begin
| name = Mu<sup>2</sup> Scorpii
| table_ref = <ref name=Squicciarini2022/>
| period_unit = year
}}
{{OrbitboxPlanet hypothetical
|status = unconfirmed
| exoplanet = c
| mass = 18.5{{±|1.5}}
| radius = <!-- Radius of the planet, in Jupiter radii -->
| radius_earth = <!-- Radius of the planet, in Earth radii -->
| semimajor =  18.9{{±|11.7|5.0}}
| period = <!--Orbital period of the planet, in days-->
| eccentricity = 0.61{{±|0.19|0.32}}
| inclination = 62.8{{±|9.9|16.6}}
}}
{{OrbitboxPlanet
| exoplanet = b
| mass = 14.4{{±|0.8}}
| radius = <!-- Radius of the planet, in Jupiter radii -->
| radius_earth = <!-- Radius of the planet, in Earth radii -->
| semimajor = 242.4{{±|114.5|52.1}}
| period = <!--Orbital period of the planet, in days-->
| eccentricity = 0.56{{±|0.27|0.26}}
| inclination = 96.6{{±|21.5|20.5}}
}}
{{Orbitbox end}}
==References==
{{Reflist|refs=
<ref name=vanLeeuwen2007>{{citation
| first=F. | last=van Leeuwen
| title=Validation of the new Hipparcos reduction
| journal=Astronomy and Astrophysics
| volume=474 | issue=2 | pages=653–664 | date=November 2007
| bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357
| arxiv=0708.1752 | s2cid=18759600
| postscript=. }}</ref>
<ref name=Anderson2012>{{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 | s2cid=119257644 | postscript=. }}</ref>
<ref name=Underhill1979>{{citation
| display-authors=1
| last1=Underhill | first1=A. B. | last2=Divan | first2=L.
| last3=Prevot-Burnichon | first3=M.-L. | last4=Doazan | first4=V.
| title=Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars
| journal=[[Monthly Notices of the Royal Astronomical Society]]
| volume=189 | pages=601–605 |date=November 1979
| issue=3 | bibcode=1979MNRAS.189..601U | doi=10.1093/mnras/189.3.601
| postscript=. | doi-access=free }}</ref>
<ref name=Gutierrez-Moreno1968>{{citation
| 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
| postscript=. | doi-access=free }}</ref>
<ref name=Uesugi1970>{{citation
| last1=Uesugi | first1=Akira | last2=Fukuda | first2=Ichiro
| title=Catalogue of rotational velocities of the stars
| journal=Contributions from the Institute of Astrophysics and Kwasan Observatory
| date=1970 | publisher=[[University of Kyoto]]
| bibcode=1970crvs.book.....U | postscript=. }}</ref>
<ref name=rgcrv>{{citation
| last=Evans | first=D. S. | date=June 20–24, 1966
| editor1-last=Batten | editor1-first=Alan Henry
| editor2-last=Heard | editor2-first=John Frederick
| title=The Revision of the General Catalogue of Radial Velocities
| work=Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30
| volume=30 | page=57 | location=University of Toronto
| publisher=[[International Astronomical Union]]
| bibcode=1967IAUS...30...57E | postscript=.}}</ref>
<ref name=Hiltner1969>{{citation
| display-authors=1 | last1=Hiltner | first1=W. A.
| last2=Garrison | first2=R. F. | last3=Schild | first3=R. E.
| title=MK Spectral Types for Bright Southern OB Stars
| journal=[[The Astrophysical Journal]]
| volume=157 | pages=313 |date=July 1969
| doi=10.1086/150069 | bibcode=1969ApJ...157..313H
| postscript=. | doi-access=free }}</ref>
<ref name=Mcdonald2012>{{citation
| display-authors=1 | last1=McDonald | first1=I.
| last2=Zijlstra | first2=A. A | last3=Boyer | first3=M. L.
| title=Fundamental Parameters and Infrared Excesses of Hipparcos Stars
| journal=Monthly Notices of the Royal Astronomical Society
| volume=427 | issue=1 | pages=343–57 | date=2012
| bibcode=2012MNRAS.427..343M | doi = 10.1111/j.1365-2966.2012.21873.x
| doi-access=free | arxiv = 1208.2037 | s2cid=118665352 | postscript=. }}</ref>
<ref name=Tetzlaff2011>{{citation
| title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun
| journal=Monthly Notices of the Royal Astronomical Society
| display-authors=1 | last1=Tetzlaff | first1=N.
| last2=Neuhäuser | first2=R.| last3=Hohle | first3=M. M.
| volume= 410 | pages=190–200 | year=2011
| issue=1
| bibcode=2011MNRAS.410..190T | doi=10.1111/j.1365-2966.2010.17434.x
| doi-access=free
| arxiv=1007.4883 | s2cid=118629873
| postscript=. }}</ref>
<ref name=Bobylev2007>{{citation
| title=Kinematics of the Scorpius–Centaurus OB association
| last1=Bobylev | first1=V. V. | last2=Bajkova | first2=A. T.
| journal=Astronomy Letters
| volume=33 | issue=9 | pages=571–583 | date=September 2007
| doi=10.1134/S1063773707090010 | bibcode=2007AstL...33..571B
| postscript=. |arxiv = 0708.0943 | s2cid=15785349 }}</ref>
<ref name=SIMBAD>{{cite simbad
| title=mu.02 Sco
| accessdate=2016-09-20 | postscript=. }}</ref>
<!--
<ref name=Allen1899>{{citation
| first1=Richard Hinckley | last1=Allen | year=1899 | edition=1963 Dover reprint
| title=Star-Names and Their Meanings | chapter=Scorpio
| publication-place=New York | publisher=G.E. Stechert, 1899
| chapter-url=http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Scorpio*.html
| accessdate=2016-09-22 | postscript=. }}</ref>
-->
}}
==External links==
*[https://www.facebook.com/CookIslandsDancingVids/videos/789422281077425/ The beautiful maidens from the Once, Upon a Reef], on: Facebook, Cook Islands Dance Video's
{{Stars of Scorpius|state=collapsed}}
{{DEFAULTSORT:Mu2 Scorpii}}
[[Category:Bayer objects|Scorpii, Mu2]]
[[Category:B-type subgiants]]
[[Category:Scorpius]]
[[Category:Henry Draper Catalogue objects|151985]]
[[Category:Hipparcos objects|082545]]
[[Category:Bright Star Catalogue objects|6252]]
[[Category:Upper Centaurus Lupus]]
[[Category:Durchmusterung objects]]
[[Category:Stars with proper names|Pipirima]]
[[Category:Planetary systems with one confirmed planet]]