Editing Delta Scorpii

{{Short description|Binary star system in the constellation Scorpius}}
{{Starbox begin
 | name = δ Scorpii
}}
{{Starbox image
 | image=
{{Location mark
|image=Scorpius constellation map.svg
|float=center
|alt=
|label=
|position=right
|width=280
|mark=Red circle.svg
|mark_width=12
|mark_link=δ Scorpii
|x=802|y=312
}}
|caption=Location of δ Scorpii (circled)
}}
{{Starbox observe
 | constell    = [[Scorpius]]
 | epoch       = J2000
 | ra          = {{RA|16|00|20.00528}}<ref name=aaa474_2_653/>
 | dec         = {{DEC|-22|37|18.1431}}<ref name=aaa474_2_653/>
 | appmag_v    = 1.59 - 2.32<ref name=vsx/>
}}
{{Starbox character
 | class       = B0.3&nbsp;IV<ref name=mnras309_1_221/> + B1-3V<ref name=miro/>
 | b-v         = −0.124<ref name=apjs15/>
 | u-b         = −0.920<ref name=apjs15/>
 | variable    = [[Gamma Cassiopeiae variable|γ Cas]]<ref name=gcvs/>
}}
{{Starbox astrometry
 | radial_v    = −7<ref name=rgcrv/>
 | prop_mo_ra  = −10.21<ref name=aaa474_2_653/>
 | prop_mo_dec = −35.41<ref name=aaa474_2_653/>
 | parallax    = 6.64
 | p_error     = 0.89
 | parallax_footnote = <ref name=aaa474_2_653/>
 | dist_pc     = 136.0<ref name=miro/>
 | absmag_v    = −3.8<ref name=aaa216_1_44/>
}}
{{Starbox orbit
 | reference = <ref name=miro/><ref name=aaa532_A80/>
 | period = {{val|10.8092|0.0005|fmt=commas}}
 | axis = {{val|0.09874|0.00007|fmt=commas}}
 | axis_unitless = {{val|13.5|0.1|u=AU}}
 | eccentricity = {{val|0.936|0.003}}
 | inclination = {{val|36|1}}
 | node = {{val|174.0|2.5}}
 | periastron = 2011 July 3rd
 | periarg = {{val|-2.3|3.8}}
 | k1 = {{val|23.9|0.8}}
}}
{{Starbox detail
 | component1 = δ Sco A
 | mass        = 13<ref name=miro/>
 | radius      = 8.5<ref name=aaa532_A80/>
 | luminosity  = 38,000<ref name=Pecaut/>
 | temperature = 27,400<ref name=Pecaut/>
 | metal_fe    =
 | gravity     = 3.92<ref name=aaa216_1_44/>
 | rotational_velocity = 180<ref name=mnras309_1_221/>
 | component2 = δ Sco B
 | mass2 = 8.2<ref name=miro/>
 | temperature2 = 20-24,000<ref name=miro/>
 | age_myr2     = {{nowrap|9-10}}<ref name=miro/><ref name=Pecaut/>
}}
{{Starbox catalog
 | names = Dschubba, Dzuba,<ref name=moore/> Al&nbsp;Jabba,<ref name=moore/> Iclarkrau,<ref name=moore/> [[Flamsteed designation|7]]&nbsp;Scorpii, [[Bonner Durchmusterung|BD]]&minus;22°4068, [[Henry Draper catalogue|HD]]&nbsp;143275, [[Hipparcos catalogue|HIP]]&nbsp;78401, [[Harvard Revised catalogue|HR]]&nbsp;5953, [[Fifth Fundamental Catalogue|FK5]]&nbsp;594, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]]&nbsp;184014, [[Catalogue of Components of Double and Multiple Stars|CCDM]]&nbsp;16003-2237
}}
{{Starbox reference
|Simbad=Delta+Scorpii
}}
{{Starbox end}}

'''Delta Scorpii''' ([[Latinisation of names|Latinised]] from '''δ Scorpii''', abbreviated '''Delta Sco''', '''δ Sco''') is a [[binary star]] (the presence of a third star in the system is being debated<ref name=miro/>) in the [[constellation]] of [[Scorpius]]. The primary star is named '''Dschubba''' {{IPAc-en|'|dZ|V|b|@}}.<!--this appears to be one of those annoying cases where K&S don't bother to give the English pronunciation because it's the same as their ad hoc pseudo-Arabic pronunciation.--><ref name=Kunitzsch/><ref name="IAU-CSN"/>

==Observation==
[[File:DeltaScoLightCurve.png|thumb|left|A [[Photometric_system#Photometric_letters|visual band]] [[light curve]] for Delta Scorpii. The main plot (adapted from Suffak ''et al.''<ref name="Suffak"/>) shows the long-term variability, and the inset plot (adapted from Miroshnichenko ''et al.''<ref name="AnAv377"/>) shows the brightening which occurred in 2000.]]
Delta Scorpii is 2.0 degrees south of the [[ecliptic]].  It is a binary star with two components of magnitudes 2.4 and 4.6 separated by {{val|0.2|ul="}}.<ref name=wds/>  In 1981 it was [[occultation|occulted]] by [[Rings of Saturn|Saturn's rings]] as seen by [[Voyager 2]], with starlight unexpectedly blocked even by the apparently empty gaps, indicating that "there is very little empty space anywhere in the main ring system."<ref name=DBoA/>

===Variability===
Delta Scorpii A is a [[Gamma Cassiopeiae variable]] star. This type of star shows irregular slow brightness variations of a few hundredths of a magnitude due to material surrounding the star.

In June 2000 Delta Scorpii was observed by Sebastian Otero to be 0.1 magnitudes brighter than normal; its brightness has varied since then and has reached at least as high as magnitude 1.6, altering the familiar appearance of Scorpius. Spectra taken after the outburst began have shown that the star is throwing off luminous gases from its equatorial region. The companion passed close by in 2011, again resulting in the star peaking at 1.65 between 5 and 15 July 2011.<ref name=miro/><ref name=sigismondo/>
{{clear left}}
==Nomenclature==
[[File:Rho Ophiucus Widefield.jpg|thumb|left|[[Rho Ophiuchi|ρ Ophiuchi]] region. δ Scorpii is the bright white star on the left (north is down).]]''δ Scorpii'' (Latinised to ''Delta Scorpii'') is the system's [[Bayer designation]]. The two components are designated ''Delta Scorpii A'' and ''B''.

Delta Scorpii bore the traditional name ''Dschubba'', which comes from Arabic جبهة العقرب ''jabhet al-aqrab'' meaning 'the forehead of 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 catalogue and standardize proper names for stars. The WGSN approved the name ''Dschubba'' for ''δ'' ''Scorpii A'' on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.<ref name="IAU-CSN" />

In [[Chinese astronomy|Chinese]], {{lang|zh|房宿}} ({{lang|zh-Latn|Fáng Xiù}}), meaning ''[[Room (Chinese constellation)|Room]]'', refers to an asterism consisting of δ Scorpii, [[Beta1 Scorpii|β<sup>1</sup> Scorpii]], [[Beta2 Scorpii|β<sup>2</sup> Scorpii]], [[Pi Scorpii|π Scorpii]], and [[Rho Scorpii|ρ Scorpii]].<ref name=zh/> Consequently, the [[Chinese star names|Chinese name]] for δ Scorpii itself is {{lang|zh|房宿三}} ({{lang|zh-Latn|Fáng Xiù sān}}), "the Third Star of Room".<ref name=lcsd/>
{{clear left}}

==Properties==
δ Scorpii was once used as a spectroscopic standard for the B0 IV classification, but is now considered too unusual and variable.<ref name="miro" />

The primary, δ Scorpii A, is a B class subgiant surrounded by a disc of material spun off by the rapidly rotating star. The secondary, δ Scorpii B, orbits every 10.5 years in a highly elongated elliptical orbit; it appears to be a normal B class [[main sequence]] star. There have been reports that Delta Scorpii A is itself a very close spectroscopic binary, but this does not appear to be the case.<ref name="miro" />

δ Scorpii is a [[proper motion]] member of the Upper Scorpius subgroup of the [[Scorpius–Centaurus association|Scorpius–Centaurus]] [[Stellar kinematics#OB associations|OB association]], the nearest such co-moving association of massive stars to the [[Sun]].<ref name="aaa216_1_44" /><ref name="Pecaut"/> The Upper Scorpius subgroup contains thousands of young stars with mean age 11 million years at average distance of 470 light years (145 parsecs).<ref name="Pecaut" />

==References==
{{reflist|refs=

<ref name=wds>{{cite journal
 | display-authors=1
 | last1=Mason | first1=B. D.
 | last2=Wycoff | first2=G. L.
 | last3=Hartkopf | first3=W. I.
 | last4=Douglass | first4=G. G.
 | last5=Worley | first5=C. E.
 | title=The Washington Visual Double Star Catalog
 | year=2014 | bibcode=2001AJ....122.3466M
 | doi = 10.1086/323920 | volume=122 | journal=The Astronomical Journal | issue=6 | pages=3466–3471| doi-access=free}}</ref>

<ref name=vsx>{{cite web |url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=34003 |title=Delta Sco |website=International Variable Star Index |publisher=[[AAVSO]] |access-date=2022-07-29}}</ref>

<ref name="Pecaut">{{Cite journal|author=Mark J. Pecaut|author2=Eric E. Mamajek|author3=Eric J. Bubar|name-list-style=amp|date=February 2012|title=A Revised Age for Upper Scorpius and the Star Formation History among the F-type Members of the Scorpius-Centaurus OB Association|journal=Astrophysical Journal|volume=746|issue=2|pages=154|arxiv=1112.1695|bibcode=2012ApJ...746..154P|doi=10.1088/0004-637X/746/2/154|s2cid=118461108}}</ref>

<ref name=moore>{{cite book|doi=10.1007/978-1-4419-6409-0_24|chapter=Scorpion in the Sky|title=The Sky at Night|pages=95–98|year=2010|last1=Moore|first1=Patrick|isbn=978-1-4419-6408-3}}</ref>

<ref name="IAU-CSN">{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt | title=IAU Catalog of Star Names |access-date=28 July 2016}}</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=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=DBoA>{{cite book|url=https://books.google.com/books?id=fDDpBwAAQBAJ&pg=PA175|title=The Data Book of Astronomy|last=Moore|first=Patrick|publisher=[[CRC Press]]|year=2000|isbn=9781420033441}}</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="WGSN">{{citation
 | url=https://www.iau.org/science/scientific_bodies/working_groups/280/
 | title=IAU Working Group on Star Names (WGSN)
 | publisher=[[International Astronomical Union]]
 | access-date=22 May 2016 | postscript=. }}</ref>

<ref name=miro>{{cite journal|doi=10.1088/0004-637X/766/2/119 |title=THE 2011 PERIASTRON PASSAGE OF THE Be BINARY δ Scorpii|journal=The Astrophysical Journal|volume=766|issue=2|pages=119|year=2013|last1=Miroshnichenko|first1=A. S.|last2=Pasechnik|first2=A. V.|last3=Manset|first3=N.|last4=Carciofi|first4=A. C.|last5=Rivinius|first5=Th.|last6=Štefl|first6=S.|last7=Gvaramadze|first7=V. V.|last8=Ribeiro|first8=J.|last9=Fernando|first9=A.|last10=Garrel|first10=T.|last11=Knapen|first11=J. H.|last12=Buil|first12=C.|last13=Heathcote|first13=B.|last14=Pollmann|first14=E.|last15=Mauclaire|first15=B.|last16=Thizy|first16=O.|last17=Martin|first17=J.|last18=Zharikov|first18=S. V.|last19=Okazaki|first19=A. T.|last20=Gandet|first20=T. L.|last21=Eversberg|first21=T.|last22=Reinecke|first22=N.|bibcode=2013ApJ...766..119M|arxiv = 1302.4021 |s2cid=38692193}}</ref>

<ref name=gcvs>{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)|journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S|volume=1|pages=02025|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009|display-authors=etal}}</ref>

<ref name=aaa474_2_653>{{cite journal | first=F. | last=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=mnras309_1_221>{{cite journal | last1=Balona | first1=L. A. | last2=Dziembowski | first2=W. A. | title=Excitation and visibility of high-degree modes in stars | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=309 | issue=1 | pages=221–232 |date=October 1999 | doi=10.1046/j.1365-8711.1999.02821.x | bibcode=1999MNRAS.309..221B | doi-access=free }}</ref>

<ref name="AnAv377">{{cite journal |last1=Miroshnichenko |first1=A. S. |last2=Fabregat |first2=J. |last3=Bjorkman |first3=K. S.|author3-link=Karen Bjorkman |last4=Knauth |first4=D. C. |last5=Morrison |first5=N. D. |last6=Tarasov |first6=A. E. |last7=Reig |first7=P. |last8=Negueruela |first8=I. |last9=Blay |first9=P. |title=Spectroscopic observations of the δ Scorpii binary during its recent periastron passage |journal=Astronomy and Astrophysics |date=October 2001 |volume=377 |issue=2 |pages=485–495 |doi=10.1051/0004-6361:20010911|arxiv=astro-ph/0106492 |bibcode=2001A&A...377..485M|s2cid=14372764 |url=https://www.aanda.org/articles/aa/pdf/2001/38/aa1284.pdf |access-date=29 July 2022}}</ref>

<ref name=aaa216_1_44>{{cite journal | last1=de Geus | first1=E. J. | last2=de Zeeuw | first2=P. T. | last3=Lub | first3=J. | title=Physical parameters of stars in the Scorpio-Centaurus OB association | journal=Astronomy and Astrophysics | volume=216 | issue=1–2 | pages=44–61 |date=June 1989 | bibcode=1989A&A...216...44D }}</ref>

<ref name="Suffak">{{cite journal |last1=Suffak |first1=M. W. |last2=Jones |first2=C. E. |last3=Tycner |first3=C. |last4=Henry |first4=G. W/ |last5=Carciofi |first5=A. C. |last6=Mota |first6=B. C. |last7=Rubio |first7=A. C. |title=The Large-scale Behavior in the Disk of δ Scorpii from 2000 to 2018 |journal=The Astrophysical Journal |date=February 2020 |volume=890 |issue=1 |page=86 |doi=10.3847/1538-4357/ab68dc|arxiv=2001.04966 |bibcode=2020ApJ...890...86S |s2cid=210473366 |doi-access=free }}</ref>

<ref name=rgcrv>{{cite conference | 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 | volume=30 | pages=57 | conference=IAU Symposium no. 30 | book-title=Determination of Radial Velocities and their Applications  | location=University of Toronto | publisher=International Astronomical Union | bibcode=1967IAUS...30...57E }}</ref>

<ref name=apjs15>{{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=aaa532_A80>{{cite journal | display-authors=1 | last1=Meilland | first1=A. | last2=Delaa | first2=O. | last3=Stee | first3=Ph. | last4=Kanaan | first4=S. | last5=Millour | first5=F. | last6=Mourard | first6=D. | last7=Bonneau | first7=D. | last8=Petrov | first8=R. | last9=Nardetto | first9=N. | last10=Marcotto | first10=A. | last11=Roussel | first11=A. | last12=Clausse | first12=J. M. | last13=Perraut | first13=K. | last14=McAlister | first14=H. | last15=Ten Brummelaar | first15=T. | last16=Sturmann | first16=J. | last17=Sturmann | first17=L. | last18=Turner | first18=N. | last19=Ridgway | first19=S. T. | last20=Farrington | first20=C. | last21=Goldfinger | first21=P. J. | title=The binary Be star δ Scorpii at high spectral and spatial resolution. I. Disk geometry and kinematics before the 2011 periastron | journal=Astronomy & Astrophysics | volume=532 | page=A80 |date=August 2011 | doi=10.1051/0004-6361/201116798 | bibcode=2011A&A...532A..80M |arxiv = 1106.1746 | s2cid=118501743 }}</ref>

<ref name=sigismondo>{{citation |author=Sigismondi, Costantino |title=Differential photometry of delta Scorpii during 2011 periastron |volume=1112 |pages=2356 |date=2011|arxiv=1112.2356 |bibcode=2011arXiv1112.2356S }}</ref>

}}

==External links==
* Jim Kaler's Stars, University of Illinois: [https://web.archive.org/web/20051123223503/http://www.astro.uiuc.edu/~kaler/sow/dschubba.html Dschubba]
* [http://skyandtelescope.com/news/current/article_462_1.asp Delta Scorpii brighter than ever] (''[[Sky and Telescope]]'', February 4, 2002)
* [http://skyandtelescope.com/news/article_986_1.asp Delta Scorpii still showing off] (''[[Sky and Telescope]]'', June 25, 2003)
* [http://www.aavso.org/vsots_delsco Delta Scorpii: the birth of a Be star] (''[[AAVSO]]'' article)

{{Stars of Scorpius}}

[[Category:Scorpius]]
[[Category:Bayer objects|Scorpii, Delta]]
[[Category:B-type subgiants]]
[[Category:Stars with proper names|Dschubba]]
[[Category:Upper Scorpius]]
[[Category:B-type main-sequence stars]]
[[Category:Binary stars]]
[[Category:Gamma Cassiopeiae variable stars]]
[[Category:Be stars]]
[[Category:Durchmusterung objects|BD-22 4068]]
[[Category:Bright Star Catalogue objects|5953]]
[[Category:Hipparcos objects|078401]]
[[Category:Henry Draper Catalogue objects|143275]]
[[Category:Flamsteed objects|Scorpii, 07]]