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}}

| dec = {{DEC|-22|37|18.1431}}

| appmag_v = 1.59 - 2.32

}}

{{Starbox character

| class = B0.3 IV + B1-3V

| b-v = −0.124

| u-b = −0.920

| variable = γ Cas

}}

{{Starbox astrometry

| radial_v = −7

| prop_mo_ra = −10.21

| prop_mo_dec = −35.41

| parallax = 6.64

| p_error = 0.89

| parallax_footnote =

| dist_pc = 136.0

| absmag_v = −3.8

}}

{{Starbox orbit

| reference =

| 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

| radius = 8.5

| luminosity = 38,000

| temperature = 27,400

| metal_fe =

| gravity = 3.92

| rotational_velocity = 180

| component2 = δ Sco B

| mass2 = 8.2

| temperature2 = 20-24,000

| age_myr2 = {{nowrap|9-10}}

}}

{{Starbox catalog

| names = Dschubba, Dzuba, Al Jabba, Iclarkrau, 7 Scorpii, BD−22°4068, HD 143275, HIP 78401, HR 5953, FK5 594, SAO 184014, CCDM 16003-2237

}}

{{Starbox reference

|Simbad=Delta+Scorpii

}}

Delta Scorpii (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) in the constellation of Scorpius. The primary star is named Dschubba {{IPAc-en|'|dZ|V|b|@}}.

Observation

File:DeltaScoLightCurve.png light curve for Delta Scorpii. The main plot (adapted from Suffak et al.) shows the long-term variability, and the inset plot (adapted from Miroshnichenko et al.) 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="}}. In 1981 it was occulted by 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."

=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.

Nomenclature

File:Rho Ophiucus Widefield.jpg 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 Working Group on Star Names (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.

In Chinese, {{lang|zh|房宿}} ({{lang|zh-Latn|Fáng Xiù}}), meaning Room, refers to an asterism consisting of δ Scorpii, β¹ Scorpii, β² Scorpii, π Scorpii, and ρ Scorpii. Consequently, the Chinese name for δ Scorpii itself is {{lang|zh|房宿三}} ({{lang|zh-Latn|Fáng Xiù sān}}), "the Third Star of Room".

Properties

δ Scorpii was once used as a spectroscopic standard for the B0 IV classification, but is now considered too unusual and variable.

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.

δ Scorpii is a proper motion member of the Upper Scorpius subgroup of the Scorpius–Centaurus OB association, the nearest such co-moving association of massive stars to the Sun. The Upper Scorpius subgroup contains thousands of young stars with mean age 11 million years at average distance of 470 light years (145 parsecs).

References

{{reflist|refs=

{{cite journal

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{{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}}

{{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}}

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

{{cite book

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|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

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{{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.

{{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}}

{{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}}.

{{citation

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| title=IAU Working Group on Star Names (WGSN)

| publisher=International Astronomical Union

| access-date=22 May 2016 | postscript=. }}

{{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}}

{{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}}

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{{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 }}

{{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}}

{{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 }}

{{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 }}

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{{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 }}

}}

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)

Category:Scorpius

Scorpii, Delta

Category:B-type subgiants

Dschubba

Category:Upper Scorpius

Category:B-type main-sequence stars

Category:Binary stars

Category:Gamma Cassiopeiae variable stars