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|@}}
| epoch = J2000
| appmag_v = {{nowrap|1.62 + 14.9 + 12.0}}
| constell = Scorpius
}}
{{Starbox character
| class = {{nowrap|B1.5IV + B2IV}}
| variable = Beta Cephei (A)
}}
{{Starbox astrometry
| component_name = (component A)
| prop_mo_dec = −29.95
| parallax = 5.71
| p_error = 0.90
}}
{{Starbox orbit
| primary = A
| name = B
| period = 2.8825
| axis_unitless = {{val|49.3|ul=mas}}
| eccentricity = 0.121
| inclination = 77.2
}}
{{Starbox orbit
| primary = Aa
| name = Ab
| period_unitless = {{val|5.9520|ul=d}}
| eccentricity = 0.26
| k1 = 39.3
}}
{{Starbox detail
| component1 = λ Sco Aa
| temperature = {{val|25000|1000|fmt=commas}}
| rotation = {{val|3.4|0.5|ul=d}}
| age_myr =
| component2 = λ Sco B
| temperature2 = {{val|25000|1000|fmt=commas}}
}}
{{Starbox detail|no_heading=y
| component1 = λ Sco Ab
}}
{{Starbox catalog
| names = {{odlist | name=Shaula | F=35 Scorpii, 35 Sco | HR=6527 | CD=-37 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 Latinised from λ Scorpii and abbreviated Lambda Sco or λ Sco. With an apparent visual magnitude of 1.62, it is one of the 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 Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 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, {{lang|zh|尾宿}} ({{lang|zh-Latn|Wěi Xiù}}), meaning Tail, refers to an asterism consisting of λ Scorpii, ε Scorpii, ζ1 Scorpii, ζ2 Scorpii, η Scorpii, θ Scorpii, ι1 Scorpii, ι2 Scorpii, κ Scorpii, μ1 Scorpii, and υ Scorpii. Consequently, the Chinese name for λ Scorpii itself is {{lang|zh|尾宿八}} ({{lang|zh-Latn|Wěi Xiù bā}}), "the Eighth Star of Tail".
Together with υ Scorpii (Lesath), Shaula is listed in the Babylonian compendium MUL.APIN as dSharur4 u dShargaz, meaning "Sharur and Shargaz".
In Coptic, they were called Minamref.
The indigenous Boorong people of northwestern Victoria (Australia) named it (together with Upsilon Scorpii) Karik Karik, "the Falcons".
Properties
File:LambdaScoLightCurve.png for Lambda Scorpii, plotted from TESS data. The large dips in brightness are eclipses, and the rapid oscillations show the Beta Cephei variability.]]
Lambda Scorpii is located some 570 light-years away from the Sun.
Spectroscopic and interferometric observations have shown that it is actually a triple star system consisting of two B-type stars and a pre-main-sequence star. The primary star is a Beta Cephei variable star with rapid brightness changes of about a hundredth of a magnitude. 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, 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 masses, respectively. The age of the system is estimated to be in the range 10–13 million years.
A 15th-magnitude star has a separation of 42 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 units (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,{{cite Gaia DR3|5962581880247644288}} while the brighter star is a luminous background object.{{cite Gaia DR3|5962570094857321472}}
In culture
Shaula appears on the flag of Brazil, symbolizing the state of Rio Grande do Norte.
USS Shaula (AK-118) was a U.S. Navy Crater-class cargo ship named after the star.
References
{{Reflist|refs=
{{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 }}
| 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.
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| doi=10.1111/j.1365-2966.2006.10526.x| doi-access=free
|arxiv = astro-ph/0605311 |s2cid=13971499}}
| 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 }}
| 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
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| 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}}
{{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}}.
|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
}}
| url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt | title=IAU Catalog of Star Names |accessdate=28 July 2016}}
}}
{{Stars of Scorpius}}
{{Sky|17|33|36.520|-|37|06|13.76}}
Category:Beta Cephei variables