View source for Astronomy:Scutum (constellation)

{{Short description|Small constellation in the southern celestial hemisphere}}
{{Infobox constellation
|name = Scutum
|abbreviation = Sct
|genitive = Scuti
|pronounce = {{IPAc-en|ˈ|s|k|juː|t|əm}},<br />genitive {{IPAc-en|ˈ|s|k|juː|t|aɪ}}
|symbolism = the [[Engineering:Shield|Shield]]
|RA = {{RA|18.7}}
|dec= {{DEC|−10}}
|family = Hercules
|quadrant = SQ4
|areatotal = 109
|arearank = 84th
|numbermainstars = 2
|numberbfstars = 7
|numberstarsplanets = 1
|numberbrightstars = 0
|numbernearbystars = 0
|brighteststarname = [[Astronomy:Alpha Scuti|α Scuti]]
|starmagnitude = 3.85
|neareststarname = LHS 3398
|stardistancely = 41.54
|stardistancepc = 12.74
|numbermessierobjects = 2
|meteorshowers = June Scutids
|bordering = [[Astronomy:Aquila (constellation)|Aquila]]<br /> [[Astronomy:Sagittarius (constellation)|Sagittarius]]<br />[[Astronomy:Serpens|Serpens Cauda]]
|latmax = 80
|latmin = [[Earth:South Pole|90]]
|month = August
|notes=
}}

'''Scutum''' is a small [[Astronomy:Constellation|constellation]]. Its name is [[Social:Latin|Latin]] for [[Engineering:Shield|shield]], and it was originally named '''Scutum Sobiescianum''' by [[Biography:Johannes Hevelius|Johannes Hevelius]] in 1684. Located just south of the [[Celestial equator|celestial equator]], its four brightest stars form a narrow diamond shape.  It is one of the 88 [[Astronomy:IAU designated constellations|IAU designated constellations]] defined in 1922.

==History==
[[Image:Scutum Sobiescianum.PNG|thumb|left|''Scutum Sobiescianum'' in ''Firmamentum Sobiescianum sive Uranographia'' 1690]]

Scutum was named in 1684 by Polish astronomer Johannes Hevelius<ref>[http://www.ianridpath.com/startales/scutum.html Star Tales ― Scutum] by Ian Ridpath</ref> (Jan Heweliusz), who originally named it ''Scutum Sobiescianum'' (Shield of Sobieski) to commemorate the victory of the Christian forces led by Polish King John III Sobieski (Jan III Sobieski) in the Battle of Vienna in 1683. Later, the name was shortened to Scutum.

Five bright stars of Scutum ([[Astronomy:Alpha Scuti|α Sct]], [[Astronomy:Beta Scuti|β Sct]], [[Astronomy:Delta Scuti|δ Sct]], [[Astronomy:Epsilon Scuti|ε Sct]] and [[Astronomy:Eta Scuti|η Sct]]) were previously known as 1, 6, 2, 3, and 9 Aquilae respectively.<ref>{{cite journal | last=Wagman | first=M. | title=Flamsteed's Missing Stars | journal=Journal for the History of Astronomy | issue=3 | volume=18 | pages=212–213 |date=August 1987 | bibcode=1987JHA....18..209W | doi=10.1177/002182868701800305| s2cid=118445625 }}</ref>

The constellation of Scutum was adopted by the [[Organization:International Astronomical Union|International Astronomical Union]] in 1922 as one of the 88 constellations covering the entire sky, with the official abbreviation of "Sct".<ref name="pa30_469">{{cite journal | last=Russell | first=Henry Norris | title=The New International Symbols for the Constellations | journal=Popular Astronomy | volume=30 | page=469 | bibcode=1922PA.....30..469R | date=1922}}</ref> The constellation boundaries are defined by a quadrilateral. In the [[Astronomy:Equatorial coordinate system|equatorial coordinate system]], the [[Right ascension|right ascension]] coordinates of these borders lie between {{RA|18|21.6}} and {{RA|18|59.3}}, while the [[Declination|declination]] coordinates are between −3.83° and −15.94°.<ref name="boundary">{{Cite journal | title=Scutum, Constellation Boundary | journal=The Constellations | publisher=[[Organization:International Astronomical Union|International Astronomical Union]] | url=https://www.iau.org/public/themes/constellations/#sct | access-date=3 September 2020 }}</ref>

Coincidentally, the Chinese also associated these stars with battle armor, incorporating them into the larger [[Astronomy:Asterism|asterism]] known as ''Tien Pien'', i.e., the Heavenly Casque (or Helmet).<ref>Richard H. Allen (1899) Star Names and Their Meanings, p. 363</ref>

==Features==

===Stars===
[[Image:ScutumCC.jpg|thumb|left|256px|The constellation Scutum as it can be seen by the naked eye]]
[[Image:Scutum 20191227.jpg|thumb|left|256px|The constellation Scutum in the night sky, enhanced for color and contrast]]
Scutum is not a bright constellation, with the brightest star, [[Astronomy:Alpha Scuti|Alpha Scuti]], being a K-type giant star<ref name=Keenan1989>{{cite journal | bibcode=1989ApJS...71..245K | doi=10.1086/191373| title=The Perkins catalog of revised MK types for the cooler stars| journal=The Astrophysical Journal Supplement Series| volume=71| pages=245| year=1989| last1=Keenan| first1=Philip C.| last2=McNeil| first2=Raymond C.}}</ref> at magnitude 3.85. However, some stars are notable in the constellation. [[Astronomy:Beta Scuti|Beta Scuti]] is the second brightest at magnitude 4.22, followed by [[Astronomy:Delta Scuti|Delta Scuti]] at magnitude 4.72. It is also known as 6 Aquilae.<ref>{{cite journal
 | last=Wagman | first=M.
 | title=Flamsteed's Missing Stars
 | journal=Journal for the History of Astronomy | volume=18 | issue=3
 | page=212 |date=August 1987
 | bibcode=1987JHA....18..209W | doi=10.1177/002182868701800305| s2cid=118445625
 }}</ref> Beta Scuti is a binary system,<ref>{{cite journal | bibcode=2016ApJS..227....4H | title=Surveying the Bright Stars by Optical Interferometry. I. A Search for Multiplicity among Stars of Spectral Types F-K | journal=Astrophysical Journal Supplement Series | volume=227 | pages=4 | number=1 | last1=Hutter | first1=D. J.| last2=Zavala | first2=R. T. | last3=Tycner | first3=C. | last4=Benson | first4=J. A. | last5=Hummel | first5=C. A. | last6=Sanborn | first6=J. | last7=Franz | first7=O. G. | last8=Johnston | first8=K. J. | year=2016 | doi=10.3847/0067-0049/227/1/4 |arxiv = 1609.05254 | s2cid=118803592 | doi-access=free }}</ref><ref>{{cite journal | bibcode=2005AJ....129.1700P | title=The Fine Guidance Sensor Orbit of the G4 Bright Giant HD 173764 | journal=Astronomical Journal | volume=129 | issue=3 | page=1700 | last1=Parsons | first1=S. B.| last2=Franz | first2=O. G. | last3=Wassermann | first3=L. H.| year=2005 | doi=10.1086/427853 | doi-access=free }}</ref> with the primary with a spectral type similar to the Sun, although it is 1,270 times brighter. Delta Scuti is a bluish white giant star, which is now coming at the direction of the Solar System. Within 1.3 million years it will come as close to 10 light years from Earth,<ref name=aaa379_2_634>{{citation | display-authors=1 | last1=García-Sánchez | first1=J. | last2=Weissman | first2=P. R. | last3=Preston | first3=R. A. | last4=Jones | first4=D. L. | last5=Lestrade | first5=J.-F. | last6=Latham | first6=D. W. | last7=Stefanik | first7=R. P. | last8=Paredes | first8=J. M. | title=Stellar encounters with the solar system | journal=Astronomy and Astrophysics | year=2001 | volume=379 | issue=2 | pages=634–659 | bibcode=2001A&A...379..634G | doi=10.1051/0004-6361:20011330 | doi-access=free }}</ref> and will be much brighter than [[Astronomy:Sirius|Sirius]] by that time.

[[Astronomy:UY Scuti|UY Scuti]] is a red hypergiant pulsating variable star and is also one of the [[Astronomy:List of largest known stars|largest stars currently known]] with a radius over 1,700 times that of the Sun,<ref name="Torres2013">{{Cite journal | last1 = Arroyo-Torres | first1 = B. | last2 = Wittkowski | first2 = M. | last3 = Marcaide | first3 = J. M. | last4 = Hauschildt | first4 = P. H. | title = The atmospheric structure and fundamental parameters of the red supergiants AH Scorpii, UY Scuti, and KW Sagittarii | doi = 10.1051/0004-6361/201220920 | journal = Astronomy & Astrophysics | volume = 554 | pages = A76 | year = 2013 | bibcode = 2013A&A...554A..76A |arxiv = 1305.6179 | s2cid = 73575062 }}</ref><ref>{{cite journal|arxiv=2011.09184|last1=Tabernero|first1=H. M.|last2=Dorda|first2=R.|last3=Negueruela|first3=I.|last4=Marfil|first4=E.|title=The nature of VX Sagitarii|journal=Astronomy & Astrophysics|year=2021|volume=646|pages=A98|doi=10.1051/0004-6361/202039236|s2cid=227013580}}</ref> although some studies give lower estimates.<ref>{{cite journal |bibcode=2019AJ....158...20M |title=A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2 |last1=Messineo |first1=M. |last2=Brown |first2=A. G. A. |journal=[[Astronomy:The Astronomical Journal|The Astronomical Journal]] |year=2019 |volume=158 |issue=1 |pages=20 |doi=10.3847/1538-3881/ab1cbd |arxiv=1905.03744 |s2cid=148571616 |doi-access=free }}</ref> [[Astronomy:Stephenson 2 DFK 1|Stephenson 2 DFK 1]] is another red hypergiant star and is possibly the largest star currently known, with a radius of 2,150 times that of the Sun.<ref>{{Cite journal|last1=Fok|first1=Thomas K. T|last2=Nakashima|first2=Jun-ichi|last3=Yung|first3=Bosco H. K|last4=Hsia|first4=Chih-Hao|last5=Deguchi|first5=Shuji|s2cid=53393926|year=2012|title=Maser Observations of Westerlund 1 and Comprehensive Considerations on Maser Properties of Red Supergiants Associated with Massive Clusters|journal=[[Astronomy:The Astrophysical Journal|The Astrophysical Journal]]|volume=760|issue=1|pages=65|arxiv=1209.6427|bibcode=2012ApJ...760...65F|doi=10.1088/0004-637X/760/1/65}}</ref> Scutum contains several clusters of supergiant stars, including [[Astronomy:RSGC1|RSGC1]],<ref>{{Cite journal | last1 = Figer | first1 = D. F. | last2 = MacKenty | first2 = J. W. | last3 = Robberto | first3 = M. | last4 = Smith | first4 = K. | last5 = Najarro | first5 = F. | last6 = Kudritzki | first6 = R. P. | last7 = Herrero | first7 = A. | doi = 10.1086/503275 | title = Discovery of an Extraordinarily Massive Cluster of Red Supergiants | journal = The Astrophysical Journal | volume = 643 | issue = 2 | pages = 1166–1179 | year = 2006 |arxiv = astro-ph/0602146 |bibcode = 2006ApJ...643.1166F | s2cid = 18241900 }}</ref> [[Astronomy:Stephenson 2|Stephenson 2]] (which contains Stephenson 2 DFK 1)<ref>{{Cite journal | last1 = Davies | first1 = B. | last2 = Figer | first2 = D. F. | last3 = Kudritzki | first3 = R. P. | last4 = MacKenty | first4 = J. | last5 = Najarro | first5 = F. | last6 = Herrero | first6 = A. | doi = 10.1086/522224 | title = A Massive Cluster of Red Supergiants at the Base of the Scutum‐Crux Arm | journal = The Astrophysical Journal | volume = 671 | issue = 1 | pages = 781–801 | year = 2007 | bibcode=2007ApJ...671..781D|arxiv = 0708.0821| s2cid = 1447781 }}</ref><ref>{{Cite journal | year = 1990 | bibcode = 1990AJ.....99.1867S | pages = 1867 | volume = 99 | doi = 10.1086/115464 | title = A possible new and very remote galactic cluster | journal = The Astronomical Journal | last1 = Stephenson | first1 = C. B.}}</ref> and [[Astronomy:RSGC3|RSGC3]].<ref>{{Cite journal | volume = 513 | journal = Astronomy and Astrophysics | title = Another cluster of red supergiants close to RSGC1 | pages = A74 | year = 2010| bibcode = 2010A&A...513A..74N | doi = 10.1051/0004-6361/200913373 | first5 = S. | last5 = Martínez-Núñez | first2 = C. | last2 = González-Fernández | first1 = I. | last3 = Marco | first3 = A. | first4 = J. S. | last4 = Clark | last1 = Negueruela|arxiv = 1002.1823 | s2cid = 118531372 }}</ref>

===Deep sky objects===
[[Image:M1-63 Nebula.jpg|thumb|right|M1-63, a bipolar planetary nebula located in the constellation of Scutum (the Shield)]]
Although not a large constellation, Scutum contains several [[Astronomy:Open cluster|open cluster]]s, as well as a [[Astronomy:Globular cluster|globular cluster]] and a [[Astronomy:Planetary nebula|planetary nebula]]. The two best known deep sky objects in Scutum are [[Astronomy:Wild Duck Cluster|M11]] (the Wild Duck Cluster) and the open cluster M26 (NGC 6694). The globular cluster [[Astronomy:NGC 6712|NGC 6712]] and the planetary nebula [[Astronomy:IC 1295|IC 1295]] can be found in the eastern part of the constellation, only 24 arcminutes apart.

The most prominent open cluster in Scutum is the [[Astronomy:Wild Duck Cluster|Wild Duck Cluster]], M11. It was named by William Henry Smyth in 1844 for its resemblance in the eyepiece to a flock of ducks in flight. The cluster, 6200 light-years from Earth and 20 light-years in diameter, contains approximately 3000 stars, making it a particularly rich cluster. It is around 220 million years old,<ref>{{cite journal |title = So, Where Are the Wild Ducks?! |last = MacRobert |first = Alan |journal = Sky and Telescope |date = September 2012}}</ref> although some studies give older estimates.<ref>{{citation
 | title=NGC 6705 a young α-enhanced open cluster from OCCASO data
 | last1=Casamiquela | first1=L. | last2=Carrera | first2=R.
 | last3=Balaguer-Núñez | first3=L. | last4=Jordi | first4=C.
 | last5=Chiappini | first5=C. | last6=Anders | first6=F.
 | last7=Antoja | first7=T. | last8=Miret-Roig | first8=N.
 | last9=Romero-Gomez | first9=M. | last10=Blanco-Cuaresma | first10=S.
 | last11=Pancino | first11=E. | last12=Aguado | first12=D. S.
 | last13=del Pino | first13=A. | last14=Diaz-Perez | first14=L.
 | last15=Gallart | first15=C. | display-authors=1
 | journal=Astronomy & Astrophysics
 | volume=610 | id=A66 | pages=10 | date=March 2018
 | bibcode=2018A&A...610A..66C | arxiv=1710.11069
 | doi=10.1051/0004-6361/201732024 | s2cid=59397264 | postscript=. }}</ref> Estimates for the mass of the star cluster range from {{Val|3700|ul=solar mass|fmt=commas}}<ref name=WildDuck1>{{citation
 | title=The Gaia-ESO Survey: Stellar content and elemental abundances in the massive cluster NGC 6705
 | last1=Cantat-Gaudin | first1=T. | last2=Vallenari | first2=A.
 | last3=Zaggia | first3=S. | last4=Bragaglia | first4=A.
 | last5=Sordo | first5=R. | last6=Drew | first6=J. E.
 | last7=Eisloeffel | first7=J. | last8=Farnhill | first8=H. J.
 | last9=Gonzalez-Solares | first9=E. | last10=Greimel | first10=R.
 | last11=Irwin | first11=M. J. | last12=Kupcu-Yoldas | first12=A.
 | last13=Jordi | first13=C. | last14=Blomme | first14=R.
 | last15=Sampedro | first15=L. | last16=Costado | first16=M. T.
 | last17=Alfaro | first17=E. | last18=Smiljanic | first18=R.
 | last19=Magrini | first19=L. | last20=Donati | first20=P.
 | last21=Friel | first21=E. D. | last22=Jacobson | first22=H.
 | last23=Abbas | first23=U. | last24=Hatzidimitriou | first24=D.
 | last25=Spagna | first25=A. | last26=Vecchiato | first26=A.
 | last27=Balaguer-Nunez | first27=L. | last28=Lardo | first28=C.
 | last29=Tosi | first29=M. | last30=Pancino | first30=E.
 | last31=Klutsch | first31=A. | last32=Tautvaisiene | first32=G.
 | last33=Drazdauskas | first33=A. | last34=Puzeras | first34=E.
 | last35=Jiménez-Esteban | first35=F. | last36=Maiorca | first36=E.
 | last37=Geisler | first37=D. | last38=San Roman | first38=I.
 | last39=Villanova | first39=S. | last40=Gilmore | first40=G.
 | last41=Randich | first41=S. | last42=Bensby | first42=T.
 | last43=Flaccomio | first43=E. | last44=Lanzafame | first44=A.
 | last45=Recio-Blanco | first45=A. | last46=Damiani | first46=F.
 | last47=Hourihane | first47=A. | last48=Jofré | first48=P.
 | last49=de Laverny | first49=P. | last50=Masseron | first50=T.
 | last51=Morbidelli | first51=L. | last52=Prisinzano | first52=L.
 | last53=Sacco | first53=G. G. | last54=Sbordone | first54=L.
 | last55=Worley | first55=C. C. | display-authors=1
 | journal=Astronomy & Astrophysics
 | volume=569 | id=A17 | pages=18 | date=September 2014
 | doi=10.1051/0004-6361/201423851 | postscript=.
 | bibcode=2014A&A...569A..17C | arxiv=1407.1510 | s2cid=5111744 }}</ref> to {{Val|11000|ul=solar mass|fmt=commas}}.<ref name=WildDuck2>{{citation
 | title=Structure and stellar content analysis of the open cluster M 11 with 2MASS photometry
 | last1=Santos | first1=J. F. C. Jr. | last2=Bonatto | first2=C.
 | last3=Bica | first3=E. | display-authors=1
 | journal=Astronomy and Astrophysics
 | volume=442 | issue=1 | pages=201–209 | date=October 2005
 | doi=10.1051/0004-6361:20053378 | postscript=.
 | bibcode=2005A&A...442..201S | arxiv=astro-ph/0507216 | s2cid=15323948 }}</ref>

== Space exploration ==
The [[Engineering:Space probe|space probe]] [[Astronomy:Pioneer 11|Pioneer 11]] is moving in the direction of this constellation. It will not near the closest star in this constellation for over a million years<ref>Pioneer 11 is travelling at ~2.4 au/yr, 41.54 ly ≈ 2.627x10<sup>6</sup>au.</ref> at its present speed, by which time its batteries will be long dead.

==See also==
* Scutum (Chinese astronomy)
* [[Astronomy:Taurus Poniatovii|Taurus Poniatovii]] - a constellation created by the Polish astronomer [[Biography:Marcin Odlanicki Poczobutt|Marcin Odlanicki Poczobutt]] in 1777 to honor King of Poland Stanisław August Poniatowski.
[[File:Sidney Hall - Urania's Mirror - Taurus Poniatowski, Serpentarius, Scutum Sobiesky, and Serpens.jpg|200px|thumb|right|[[Astronomy:Serpens|Serpens]] held by Ophiuchus, as depicted in ''Urania's Mirror'', a set of constellation cards published in London c. 1825. Above the tail of the serpent is the now-obsolete constellation Taurus Poniatovii while below it is Scutum.]]

==References==
{{Reflist}}

==Sources==
* Ian Ridpath and Wil Tirion (2017). ''Stars and Planets Guide'' (5th ed.), Collins, London. {{ISBN|978-0-00-823927-5}}. Princeton University Press, Princeton. {{ISBN|978-0-69-117788-5}}.

==External links==
* [http://www.allthesky.com/constellations/scutum/ The Deep Photographic Guide to the Constellations: Scutum]

{{Stars of Scutum}}
{{Constellations}}
{{ConstellationsByHevelius}}

{{Sky|18|42|00|-|10|00|00|10}}

{{DEFAULTSORT:Scutum (constellation)}}
[[Category:Scutum (constellation)| ]]
[[Category:Southern constellations]]

{{Sourceattribution|Scutum (constellation)}}