Mu2 Scorpii
{{hatnote|For other star systems with a similar Bayer designation, see Mu Scorpii.}}
{{DISPLAYTITLE:Mu2 Scorpii}}
{{short description|B-type star in the constellation of Scorpius}}
{{Starbox begin
| name = μ2 Scorpii
(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=μ2 Sco
|x=476|y=724
}}
|caption=Location of μ2 Scorpii (circled)
}}
{{Starbox observe
| epoch = J2000
| constell = Scorpius
| dec = {{DEC|−38|01|03.1258}}
}}
{{Starbox character
| variable =
}}
{{Starbox astrometry
| parallax = 6.88
| p_error = 0.12
}}
{{Starbox detail
| mass = {{val|9.1|0.3}}
| radius = {{val|5.6|0.2}}
| gravity = {{val|3.8|0.2}}
| temperature = {{val|21700|900|fmt=commas}}
| metal_fe =
| age_myr = {{val|20|4}}
}}
{{Starbox catalog
| names = Pipirima, μ2 Scorpii, CD−37°11037, HD 151985, HIP 82545, HR 6252, SAO 208116.
}}
{{Starbox reference
| Simbad = mu02+Sco
}}
{{Starbox end}}
Mu2 Scorpii (μ2 Scorpii, abbreviated Mu2 Sco, μ2 Sco), also named Pipirima {{IPAc-en|p|ᵻ|'|p|ɪr|ᵻ|m|ə}},{{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars |publisher=IAU.org |accessdate=16 December 2017}} is a star in the zodiac constellation of Scorpius. It has an apparent visual magnitude of +3.56, which is bright enough to be seen with the naked eye. Its distance from the Sun is about 474 light-years, as determined by parallax measurements. It is a member of the Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association. A super-Jupiter or brown dwarf is known to orbit it, and another is suspected.
Properties
Mu2 Scorpii is a blue-white B-type subgiant star with a stellar classification of B2 IV. It has an estimated diameter of 5.6 solar radii and a mass of 9.1 times the Sun's mass, and shines with 2,385 times the Sun's luminosity. The large mass of this star make it a supernova progenitor. The outer atmosphere has an effective temperature of {{val|21700|ul=K|fmt=commas}}. It is some 20 million years old and is spinning with a projected rotational velocity of 58 km/s.
Nomenclature
μ2 Scorpii (Latinised to Mu2 Scorpii) is the star's Bayer designation.
In Tahiti, a 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."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. In one account, the children become Shaula and Lesath in the tip of the tail of Scorpio, and in another they become Mu2 and Mu1 Scorpii.{{cn|date=April 2019}} (In a similar version of the story told in the Cook Islands, they become Omega1 and Omega2 Scorpii).Johannes Carl Andersen (1931) Myths and Legends of the Polynesians. 1995 Dover reprint, p.400ff.
In 2016, the IAU organized a Working Group on Star Names (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}} 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.
In Chinese astronomy, Mu2 Scorpii is called 尾宿增二.{{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 }}
Planetary system
Two sub-stellar objects slightly above deuterium burning limit (brown dwarfs) were found in 2022 by direct imaging near Mu2 Scorpii. The outer one, designated μ2 Scorpii b, is definitely an orbiting planet or brown dwarf, and the inner one is a planetary candidate.
{{OrbitboxPlanet begin
| name = Mu2 Scorpii
| period_unit = year
}}
{{OrbitboxPlanet hypothetical
|status = unconfirmed
| exoplanet = c
| mass = 18.5{{±|1.5}}
| radius =
| radius_earth =
| semimajor = 18.9{{±|11.7|5.0}}
| period =
| eccentricity = 0.61{{±|0.19|0.32}}
| inclination = 62.8{{±|9.9|16.6}}
}}
{{OrbitboxPlanet
| exoplanet = b
| mass = 14.4{{±|0.8}}
| radius =
| radius_earth =
| semimajor = 242.4{{±|114.5|52.1}}
| period =
| eccentricity = 0.56{{±|0.27|0.26}}
| inclination = 96.6{{±|21.5|20.5}}
}}
{{Orbitbox end}}
References
{{Reflist|refs=
| 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=. }}
| 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=. }}
| 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 }}
| 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=. }}
| 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=.}}
| 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 }}
| 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=. }}
| 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 }}
| title=mu.02 Sco
| accessdate=2016-09-20 | postscript=. }}
}}
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:Upper Centaurus Lupus