Editing Wild Duck Cluster

{{Short description|Open cluster in the constellation Scutum}}
{{Infobox open cluster
 | image=[[File:Eso1430a.jpg|300px]]
 | caption= Open cluster Messier 11 in Scutum
 | name  = Wild Duck Cluster
 | epoch = J2000.0
 | class = I,2,r
 | constellation = [[Scutum (constellation)|Scutum]]
 | ra  = {{RA|18|51|05.0}}<ref name=Wu2009/>
 | dec = {{Dec|-06|16|12}}<ref name=Wu2009/>
 | dist_ly   = {{Convert|1877|pc|ly|order=flip|lk=on}}<ref name=kharchenko2005/>
 | dist_pc   = 
 | appmag_v  = 5.8<ref name=OMeara1998/>
 | size_v    = {{Val|22.8|ul=arcminute}}<ref name=kharchenko2005/>
 | mass_msol = 11,000<ref name=Santos2005/>
 | radius_ly = {{Convert|29|pc|ly|disp=out}}<ref name=Santos2005/>
 | v_hb  = 
 | age   = {{Val|316|50|u=million years}}<ref name=Casamiquela2018/>
 | notes = 
 | names = [[Messier Catalog|Messier]] 11, [[New General Catalogue|NGC]] 6705, [[Collinder catalog|Cr]] 391, [[Melotte catalogue|Mel]] 213, OCl 76.0<ref name=SIMBAD/>
}}

The '''Wild Duck Cluster''' (also known as '''Messier 11''', or '''NGC 6705''') is an [[open cluster]] of stars in the [[constellation]] [[Scutum (constellation)|Scutum]] (the Shield). It was discovered by [[Gottfried Kirch]] in 1681.<ref name=OMeara1998/> [[Charles Messier]] included it in his catalogue of diffuse objects in 1764. Its popular name derives from the brighter stars forming a triangle which could resemble a flying flock of [[duck]]s<ref name=OMeara1998/> (or, from other angles, one swimming duck). The cluster is located just to the east of the Scutum Star Cloud midpoint.<ref name=Crossen2012/>

The Wild Duck Cluster is one of the richest and most compact of the known open clusters. It is one of the most massive open clusters known, and it has been extensively studied. Its age has been estimated to about 316 million years.<ref name=Casamiquela2018/> The core radius is {{cvt|1.23|pc|ly}} while the [[Globular_cluster#Radii|tidal radius]] is {{cvt|29|pc|ly}}. Estimates for the cluster's mass range from {{Val|3700|ul=solar mass|fmt=commas}}<ref name=Gaudin2014/> to {{Val|11000|u=solar mass|fmt=commas}},<ref name=Santos2005/> depending on the method chosen. The brightest cluster member is visual magnitude 8, and it has 870 members of at least magnitude 16.5. It has an integrated [[absolute magnitude]] of –6.5, and a visual [[extinction (astronomy)|extinction]] of 1.3.<ref name=Crossen2012/>

The cluster is [[metallicity|metal-rich]] with an iron abundance of [Fe/H] = {{Val|0.17|0.04}}. Despite its youth, it shows an enhancement of [[alpha process]] elements. Possibly this is due to an enhancement of its birth [[molecular cloud]] by a nearby [[Type II supernova]] explosion.<ref name=Casamiquela2018/> At least nine [[variable star]] members have been identified with high probability, plus 29 lower probability members. The former include two [[eclipsing binary]] star systems.<ref name=Messina2010/> The cluster is located {{cvt|6.8|kpc|ly}} from the [[Galactic Center]], close to the [[galactic plane]], and is not far from its birthplace.<ref name=Casamiquela2018/>

==Gallery==
<gallery>
Wild cosmic ducks Messier 11.jpg|A portion of M11, imaged by the [[Hubble Space Telescope]]<ref>{{cite web |title=Wild cosmic ducks |url=https://www.spacetelescope.org/images/potw1912a/ |website=spacetelescope.org |access-date=25 March 2019 |language=en}}</ref>
Eso1430a.jpg|The blue stars in the centre of the image are the young, hot stars of the cluster.<ref>{{cite web|title=Wild Ducks Take Flight in Open Cluster|url=http://www.eso.org/public/news/eso1430/|website=eso.org|publisher=European Southern Observatory|access-date=3 October 2014}}</ref>
Messier11.jpg|M11 is visible with binoculars in the constellation of Scutum.
</gallery>

==See also==
* [[List of Messier objects]]

==References==
{{reflist|refs=

<ref name=SIMBAD>{{cite simbad | title=M 11 | access-date=November 10, 2018 }}</ref>

<ref name=OMeara1998>{{citation
 | title=Deep-Sky Companions: The Messier Objects
 | first1=Stephen James | last1=O'Meara | first2=David H. | last2=Levy |author-link2=David H. Levy
 | publisher=Cambridge University Press | postscript=.
 | year=1998 | isbn=978-0521553322 | page=65
 | url=https://books.google.com/books?id=jis4evHuuzUC&pg=PA65 }}</ref>

<ref name=kharchenko2005>{{Citation 
 | last1=Kharchenko | first1=N. V. | last2=Piskunov | first2=A. E.
 | last3=Röser | first3=S. | last4=Schilbach | first4=E.
 | last5=Scholz | first5=R.-D. | display-authors=1
 | title=Astrophysical parameters of Galactic open clusters
 | journal=Astronomy and Astrophysics
 | volume=438 | issue=3 | pages=1163–1173 | year=2005
 | bibcode=2005A&A...438.1163K | arxiv=astro-ph/0501674
 | doi=10.1051/0004-6361:20042523 | s2cid=9079873 | postscript=. }}</ref>

<ref name=Wu2009>{{Citation | display-authors=1
 | last1=Wu | first1 = Zhen-Yu | last2=Zhou | first2 = Xu
 | last3=Ma | first3 = Jun | last4=Du | first4 = Cui-Hua
 | title=The orbits of open clusters in the Galaxy
 | journal=[[Monthly Notices of the Royal Astronomical Society]]
 | volume=399 | issue=4 | pages=2146–2164 | date=November 2009
 | arxiv=0909.3737 | bibcode=2009MNRAS.399.2146W
 | doi=10.1111/j.1365-2966.2009.15416.x | doi-access=free | s2cid=6066790 | postscript=. }}</ref>

<ref name=Casamiquela2018>{{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>

<ref name=Messina2010>{{citation
 | title=ACE-OC project: rotation and variability in the open cluster M 11 (NGC 6705)
 | last1=Messina | first1=S. | last2=Parihar | first2=P.
 | last3=Koo | first3=J. -R. | last4=Kim | first4=S. -L.
 | last5=Rey | first5=S. -C. | last6=Lee | first6=C. -U.
 | journal=Astronomy and Astrophysics | display-authors=1
 | volume=513 | id=A29 | pages=26 | date=April 2010
 | doi=10.1051/0004-6361/200912373 | postscript=.
 | bibcode=2010A&A...513A..29M | arxiv=0912.4131 | s2cid=119249067 }}</ref>

<ref name=Santos2005>{{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>

<ref name=Crossen2012>{{citation
 | title=Sky Vistas: Astronomy for Binoculars and Richest-Field Telescopes
 | first1=Craig | last1=Crossen | first2=Gerald | last2=Rhemann
 | publisher=Springer Science & Business Media
 | year=2012 | isbn=978-3709106266 | page=56 | postscript=.
 | url=https://books.google.com/books?id=3vELBwAAQBAJ&pg=PA56 }}</ref>

<ref name=Gaudin2014>{{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>

}}

==External links==
{{commons|Messier 11|Wild Duck Cluster}}
* [http://www.messier.seds.org/m/m011.html Messier 11, SEDS Messier pages]
* [https://www.perseus.gr/Astro-DSO-NGC-6705.htm Messier 11 - LRGB result based on 2 hrs total data]
* {{WikiSky|name=The Wild Duck Cluster}}

{{Sky|18|51.1|00|-|06|16|00|6200}}
{{Portal bar|Astronomy|Stars|Outer space}}
{{Messier objects}}
{{Ngc70}}{{Scutum (constellation)}}
{{DEFAULTSORT:Wild Duck Cluster}}
[[Category:Open clusters]]
[[Category:Carina–Sagittarius Arm]]
[[Category:Messier objects|Wild Duck Cluster]]
[[Category:NGC objects]]
[[Category:Scutum (constellation)]]
[[Category:Astronomical objects discovered in 1681|?]]