Editing Lambda Scorpii

{{short description|Triple star system in the constellation Scorpius}}
{{Starbox begin
 | name=λ Scorpii
}}
{{Starbox image
 | image = {{Location mark
|image=Scorpius constellation map.svg|alt=|float=center|width=280
|label=|position=right
|mark=Red circle.svg|mark_width=12|mark_link=Shaula|x=247|y=712
}}
 | caption = Location of λ Scorpii (circled)}}
{{Starbox observe
 | pronounce    = {{IPAc-en|'|sh|ɔː|l|@}}<ref name=Kunitzsch/><ref name="IAU-CSN"/>
 | epoch        = [[J2000]]
 | ra           = {{RA|17|33|36.520}}<ref name=hipparcos/>
 | dec          = {{DEC|−37|06|13.76}}<ref name=hipparcos/>
 | appmag_v     = {{nowrap|1.62 + 14.9 + 12.0}}<ref name=hipparcos/><ref name="REED"/>
 | constell     = [[Scorpius]]
}}
{{Starbox character
 | class        = {{nowrap|B1.5IV + B2IV}}<ref name=tango/><ref name=variability/>
 | b-v          = −0.240<ref name=hamdy/>
 | u-b          = −0.880<ref name=hamdy/>
 | variable     = [[Beta Cephei variable|Beta Cephei]] (A)<ref name=handler/>
}}
{{Starbox astrometry
 | component_name = (component A)
 | radial_v     = −3.00<ref name=Gontcharov2006/>
 | prop_mo_ra   = −8.90<ref name=hipparcos/>
 | prop_mo_dec  = −29.95
 | pm_footnote  = <ref name=hipparcos/>
 | parallax     = 5.71
 | p_error      = 0.90
 | parallax_footnote = <ref name=hipparcos/>
 | absmag_v     = −3.70<ref name=balona/>
}}
{{Starbox orbit
 | reference = <ref name=msc/>
 | primary = A
 | name = B
 | period = 2.8825
 | axis_unitless = {{val|49.3|ul=mas}}
 | eccentricity = 0.121
 | inclination = 77.2
}}
{{Starbox orbit
 | reference = <ref name=msc/>
 | primary = Aa
 | name = Ab
 | period_unitless = {{val|5.9520|ul=d}}
 | eccentricity = 0.26
 | k1 = 39.3
}}
{{Starbox detail
 | component1   = λ Sco Aa
 | mass         = 10.4<ref name=tango/>
 | radius       = 8.8{{±|1.2}}<ref name=handler/>
 | luminosity   = 36,300<ref name=handler/>
 | temperature  = {{val|25000|1000|fmt=commas}}<ref name=handler/>
 | metal_fe=|gravity = 3.8<ref name=variability/>
 | rotational_velocity = 150<ref name=handler/>
 | rotation = {{val|3.4|0.5|ul=d}}<ref name=handler/>
 | age_myr      =
 | component2   = λ Sco B
 | mass2        = 8.1<ref name=tango/>
 | radius2      = 4.7{{±|1.0}}<ref name=handler/>
 | temperature2 = {{val|25000|1000|fmt=commas}}<ref name=handler/>
 | gravity2     = 4.0<ref name=variability/>
}}
{{Starbox detail|no_heading=y
 | component1 = λ Sco Ab
 | mass = 1.8<ref name=tango/>
}}
{{Starbox catalog
 | names = {{odlist | name=Shaula | F=35&nbsp;Scorpii, 35&nbsp;Sco | HR=6527 | CD=-37&nbsp;11673 | HD=158926 | SAO=208954 | FK5=652 | HIP=85927 | CCDM=J17336-3706A/B/C }}
}}
{{Starbox reference|Simbad=Lambda+Sco}}
{{Starbox end}}

'''Lambda Scorpii''' is a triple [[star system]] and the second-brightest object in the [[constellation]] of [[Scorpius]]. It is formally named '''Shaula'''; ''Lambda Scorpii'' is its [[Bayer designation]], which is [[Latinisation of names|Latinised]] from '''λ Scorpii''' and abbreviated '''Lambda Sco''' or '''λ Sco'''. With an [[apparent visual magnitude]] of 1.62, it is one of the [[List of brightest stars|brightest stars]] in the [[night sky]].

==Nomenclature==

''λ Scorpii'' (Latinised to ''Lambda Scorpii'') is the star system's [[Bayer designation]].

It bore the traditional name ''Shaula'', which comes from the [[Arabic]] الشولاء  ''al-šawlā´'' meaning 'the raised [tail]', as it is found in the tail of Scorpius, the scorpion. In 2016, the [[International Astronomical Union]] organized a [[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's first bulletin of July 2016<ref name="WGSN1"/> included a table of the first two batches of names approved by the WGSN, which included ''Shaula'' for the star λ Scorpii Aa.

In Indian Astronomy it is called MulA Nakshathram. Mūla ("root") (Devanagari मूल/मूळ) (Tamil: மூலம்) is the 19th nakshatra or "lunar mansion" in Vedic astrology. The symbol of Mula is a bunch of roots tied together (reticulated roots) or an 'elephant goad' (ankusha).{{cn|date=May 2020}}

In [[Chinese astronomy|Chinese]], {{lang|zh|尾宿}} ({{lang|zh-Latn|Wěi Xiù}}), meaning ''[[Tail (Chinese constellation)|Tail]]'', refers to an asterism consisting of λ Scorpii, [[Epsilon Scorpii|ε Scorpii]], [[Zeta1 Scorpii|ζ<sup>1</sup> Scorpii]], [[Zeta2 Scorpii|ζ<sup>2</sup> Scorpii]], [[Eta Scorpii|η Scorpii]], [[Theta Scorpii|θ Scorpii]], [[Iota1 Scorpii|ι<sup>1</sup> Scorpii]], [[Iota2 Scorpii|ι<sup>2</sup> Scorpii]], [[Kappa Scorpii|κ Scorpii]], [[Mu1 Scorpii|μ<sup>1</sup> Scorpii]], and [[Upsilon Scorpii|υ Scorpii]].<ref name=zh/> Consequently, the [[Chinese star names|Chinese name]] for λ Scorpii itself is {{lang|zh|尾宿八}} ({{lang|zh-Latn|Wěi Xiù bā}}), "the Eighth Star of Tail".<ref name=chinengstars/>

Together with [[Upsilon Scorpii|υ Scorpii]] (Lesath), Shaula is listed in the [[Babylonian astronomy|Babylonian]] compendium [[MUL.APIN]] as <sup>d</sup>Sharur<sub>4</sub> u <sup>d</sup>Shargaz, meaning "Sharur and Shargaz".<ref name=Rogers/>

In [[Coptic language|Coptic]], they were called ''Minamref''.<ref name=Burnham/>

The indigenous [[Wergaia|Boorong]] people of northwestern [[Victoria (Australia)]] named it (together with Upsilon Scorpii) ''Karik Karik'',<ref name=hamacher/> "the Falcons".<ref name=stanbridge/>

==Properties==
[[File:LambdaScoLightCurve.png|thumb|left|A [[light curve]] for Lambda Scorpii, plotted from ''[[Transiting Exoplanet Survey Satellite|TESS]]'' data.<ref name=MAST/> The large dips in brightness are eclipses, and the rapid oscillations show the Beta Cephei variability.]]
Lambda Scorpii is located some 570 [[light-year]]s away from the [[Sun]].

Spectroscopic and [[astronomical interferometer|interferometric]] observations have shown that it is actually a triple [[star system]] consisting of two [[stellar classification|B-type]] stars and a [[pre-main-sequence star]].<ref name=handler/> The primary star is a [[Beta Cephei variable]] star with rapid brightness changes of about a hundredth of a magnitude.<ref name=variability/><ref name=tango/> The pre-main-sequence star has an orbital period of 6 days and the B companion has a period of 1053 days. The three stars lie in the same orbital [[Plane (geometry)|plane]], strongly suggesting that they were formed at the same time. The masses of the primary, pre-main-sequence star and the B companion are 14.5, 2.0 and 10.6 [[solar mass]]es, respectively. The age of the system is estimated to be in the range 10–13 million years.

A 15th-[[apparent magnitude|magnitude]] star has a separation of 42 [[Minute and second of arc|arcseconds]], whereas a 12th-magnitude star is 95 arcseconds away. It is not known whether or not these components are physically associated with Lambda Scorpii. If they both were, the first would have a projected linear separation of approximately 7,500 [[astronomical unit]]s (AU) and the second approximately 17,000 AU (0.27 light-years) away.  [[Gaia Data Release 3]] reports that the fainter of these two stars is a little larger and brighter than the sun and about 420 light years away,<ref name=dr3-1>{{cite Gaia DR3|5962581880247644288}}</ref> while the brighter star is a luminous background object.<ref name=dr3-2>{{cite Gaia DR3|5962570094857321472}}</ref>

==In culture==

Shaula appears on the [[flag of Brazil]], symbolizing the state of [[Rio Grande do Norte]].

[[USS Shaula (AK-118)|USS ''Shaula'' (AK-118)]] was a [[United States Navy|U.S. Navy]] [[Crater-class cargo ship|''Crater''-class cargo ship]] named after the star.

==References==
{{Reflist|refs=

<ref name=msc>{{Cite journal|last=Tokovinin|first=Andrei|date=2018-03-01|title=The Updated Multiple Star Catalog|journal=[[The Astrophysical Journal Supplement Series]]|volume=235|issue=1|pages=6|doi=10.3847/1538-4365/aaa1a5|issn=0067-0049|arxiv=1712.04750|bibcode=2018ApJS..235....6T|s2cid=119047709 |doi-access=free }}</ref>

<ref name=tango>{{cite journal
 | bibcode=2006MNRAS.370..884T
 | title=Orbital elements, masses and distance of λ Scorpii a and B determined with the Sydney University Stellar Interferometer and high-resolution spectroscopy
 | journal=Monthly Notices of the Royal Astronomical Society|volume=370|issue=2|pages=884–890
 | last1=Tango|first1=W. J.|last2=Davis|first2=J.|last3=Ireland|first3=M. J.
 | last4=Aerts|first4=C.|last5=Uytterhoeven|first5=K.|last6=Jacob|first6=A. P.|last7=Mendez|first7=A.
 | last8=North|first8=J. R.|author9-link=Eugene Seneta|last9=Seneta|first9=E. B.|last10=Tuthill|first10=P. G.|year=2006
 | doi=10.1111/j.1365-2966.2006.10526.x| doi-access=free
 |arxiv = astro-ph/0605311 |s2cid=13971499}}</ref>

<ref name=stanbridge>{{cite journal|bibcode=1857PPIVT...2..137S|title=On the astronomy and mythology of the Aborigines of Victoria|journal=Proceedings of the Philosophical Institute of Victoria|volume=2|pages=137|last1=Stanbridge|first1=William Edward|year=1857}}</ref>

<ref name=hamacher>{{cite journal
 | last1 = Hamacher | first1 = Duane W. | last2 = Frew | first2 = David J. | date = 2010
 | title = An Aboriginal Australian Record of the Great Eruption of Eta Carinae
 | journal = Journal of Astronomical History and Heritage | volume = 13 | issue = 3
 | pages = 220–34 | doi = 10.3724/SP.J.1440-2807.2010.03.06 | arxiv = 1010.4610 | bibcode = 2010JAHH...13..220H| s2cid = 118454721 }}</ref>

<ref name=Burnham>{{cite book
 | author=Robert Burnham
 | title=Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System
 | url=https://books.google.com/books?id=PJzIt3SIlkUC|year=1978|publisher=Courier Corporation
 | location=New York|isbn=978-0-486-23673-5|page=1678}}</ref>

<ref name=Rogers>{{cite journal
 | last=Rogers | first=J. H.
 | title=Origins of the ancient constellations: I. The Mesopotamian traditions
 | journal=Journal of the British Astronomical Association |issue=1
 | volume=108 | pages=9–28 |date=February 1998
 | bibcode=1998JBAA..108....9R}}</ref>

<ref name=chinengstars>{{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=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="WGSN1">{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/WGSN_bulletin1.pdf | title=Bulletin of the IAU Working Group on Star Names, No. 1 |accessdate=28 July 2016}}</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=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=hipparcos>{{cite journal|bibcode=2007A&A...474..653V|title=Validation of the new Hipparcos reduction|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|last1=Van Leeuwen|first1=F.|year=2007|doi=10.1051/0004-6361:20078357|arxiv = 0708.1752 |s2cid=18759600}}</ref>

<ref name="REED">{{citation | last1=Reed | first1=B. Cameron | title=Catalog of Galactic OB Stars | journal=The Astronomical Journal | year=2003 | volume= 125| issue = 5 | pages=2531–2533 | bibcode=2003AJ....125.2531R | doi=10.1086/374771 | postscript=. | doi-access=free }}</ref>

<ref name=hamdy>{{cite journal|bibcode= 1993Ap&SS.203...53H|title= A catalogue of spectral classification and photometric data of B-type stars|journal= Astrophysics and Space Science|volume= 203|pages= 53–107|last1= Hamdy|first1= M. A.|last2= Abo Elazm|first2= M. S.|last3= Saad|first3= S. M.|year= 1993|issue= 1|doi= 10.1007/BF00659414|s2cid= 122459090}}</ref>

<ref name=Gontcharov2006>{{cite journal|bibcode=2006AstL...32..759G|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|last1=Gontcharov|first1=G. A.|year=2006|doi=10.1134/S1063773706110065|arxiv = 1606.08053 |s2cid=119231169}}</ref>

<ref name=balona>{{cite journal|bibcode=1975MNRAS.172..191B|title=The luminosities of the beta Canis Majoris variables, the zero age main sequence and the distance of the Sco-Cen association|journal=Monthly Notices of the Royal Astronomical Society|volume=172|pages=191–203|last1=Balona|first1=L. A.|last2=Feast|first2=M. W.|year=1975|issue=1 |doi=10.1093/mnras/172.1.191|doi-access=free}}</ref>

<ref name=handler>{{cite journal|bibcode=2013A&A...557A...1H|title=Time-resolved multicolour photometry of bright B-type variable stars in Scorpius|journal=Astronomy & Astrophysics|volume=557|pages=A1|last1=Handler|first1=G.|last2=Schwarzenberg-Czerny|first2=A.|year=2013|doi=10.1051/0004-6361/201321886|arxiv = 1307.2733 |s2cid=56403146}}</ref>

<ref name=variability>{{cite journal|doi=10.1051/0004-6361:20041223 | bibcode=2004A&A...427..581U | volume=427 | issue=2 | title=Interpretation of the variability of the β Cephei star λ Scorpii | journal=Astronomy and Astrophysics | pages=581–592| year=2004 | last1=Uytterhoeven | first1=K. | last2=Willems | first2=B. | last3=Lefever | first3=K. | last4=Aerts | first4=C. | last5=Telting | first5=J. H. | last6=Kolb | first6=U. | doi-access=free | hdl=2066/60554 | hdl-access=free }}</ref>

<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-CSN">{{cite web
 | url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt | title=IAU Catalog of Star Names |accessdate=28 July 2016}}</ref>

}}

{{Stars of Scorpius}}
{{Sky|17|33|36.520|-|37|06|13.76}}

<!-- Proeprties -->
[[Category:B-type subgiants]]
[[Category:Beta Cephei variables]]
[[Category:Multiple stars|5]]
<!-- Position/catalogues -->
[[Category:Scorpius]]
[[Category:Bayer objects|Scorpii, Lambda]]
[[Category:Bright Star Catalogue objects|6527]]
[[Category:Durchmusterung objects]]
[[Category:Flamsteed objects|Scorpii, 35]]
[[Category:Henry Draper Catalogue objects|158926]]
[[Category:Hipparcos objects|085927]]
[[Category:Stars with proper names|Shaula]]