View source for NGC 1850

{{Short description|Super star cluster in the constellation Dorado}}
{{Infobox globular cluster
 | image     = [[Image:NGC1850.jpg|280px|]]
 | caption   = A [[Hubble Space Telescope]] (HST) image of NGC 1850.
 | credit    = 
 | name      = NGC 1850
 | epoch     = J2000.0
 | constellation = [[Dorado]]
 | ra        = {{RA|05|08|50.190}}<ref name=Werchan2011/>
 | dec       = {{DEC|−68|45|35.65}}<ref name=Werchan2011/>
 | dist_ly   = 
 | dist_pc   = 
 | appmag_v  = 9.0
 | size_v    = 3.4{{prime}}
 | absmag_v  =
 | radius_ly = {{Convert|4.97|±|0.35|pc|ly|order=flip|abbr=on}}<ref name=Correnti2017/>
 | radius_tidal_ly = {{Convert|3.01|±|0.12|pc|ly|order=flip|abbr=on}}<ref name=Correnti2017/>
 | mass_msol = {{Val|41700|10800|8600|fmt=commas}}<ref name=Correnti2017/>
 | age       = {{nowrap|~100 Myr}}<ref name=Correnti2017/>
 | metal_z   = −0.3<ref name=Correnti2017/>
 | notes     = 
 | names     = [[New General Catalogue|NGC]]&nbsp;1850, ESO 056-SC070, h 2780, GC 1060
}}

'''NGC 1850''' is a [[double cluster]] and a [[super star cluster]] in the [[Dorado constellation]], located in the northwest part<ref name=Westerlund1997/> of the bar of the [[Large Magellanic Cloud]],<ref name=Gilmozzi1994/> at a distance of {{Convert|51.5|kpc|kly|abbr=on|lk=on|order=flip}} from the [[Sun]].{{cn|date=November 2021}} It was discovered by Scottish astronomer [[James Dunlop]] in 1826.

This is an unusual cluster system because the main distribution of stars is like a [[globular cluster]], but unlike the globular clusters of the [[Milky Way]] it is composed of young stars. The only similar object in the Milky Way is [[Westerlund 1]].<ref name=gallagher02/> The main cluster has the appearance of a globular cluster with an age of {{Val|50|10}}&nbsp;Myr. The second is a more loosely distributed sub-cluster with an age of {{Val|4.3|0.9}}&nbsp;Myr,<ref name=Gilmozzi1994/> located at an [[angular separation]] of {{Val|30|ul=arcsecond}} to the west of the main cluster.<ref name=Caloi1998/> There are indications of interactions between the two, with the larger component being irregular and showing a tail toward the northwest.<ref name=Westerlund1997/>

The main cluster is around 100&nbsp;million years old,<ref name=Correnti2017/> with a [[tidal radius]] of 10&nbsp;[[light year]]s and an overall radius of 16&nbsp;light years.<ref name=Correnti2017/> It has an estimated mass of 42,000 times the [[mass of the Sun]].<ref name=Correnti2017/> The stellar component is split into two [[main sequence]] populations, with about a quarter of the stars in a blue (hotter) group and the rest in a redder (cooler) population.<ref name=Correnti2017/> The cluster is embedded in an ionization region designated Henize 103.<ref name=Fischer1993/>

The much younger subcluster, often designated NGC&nbsp;1850A,<ref name=Westerlund1997/> contains a number of young, massive [[OB star|O/B-type stars]] that are on or near the [[main sequence]], distributed up to {{Val|1|ul=arcminute}} from the central clump. Seven subcluster members have masses of {{Val|35|u=solar mass|p=≥&nbsp;}}, and two of those are {{Val|50|u=solar mass|p=≥&nbsp;}}. Lower mass members up to {{Val|3|u=solar mass|p=~}} are still on the [[Pre-main-sequence star|pre-main-sequence]] stage. The age distribution of the subcluster members indicate star formation has been active almost constantly since its formation. The eastern side of the cluster is more obscured and has fewer OB stars.<ref name=Caloi1998/>

In November 2021, astronomers using [[Multi-unit spectroscopic explorer|MUSE]] on the [[Very Large Telescope]] reported the discovery of a stellar-mass [[black hole]] in NGC 1850 by viewing its influence on the motion of a star in close proximity, the first direct dynamical detection of a black hole in a young massive cluster.<ref>{{cite news |title=Black hole found hiding in star cluster outside our galaxy |url=https://www.eso.org/public/news/eso2116/|date=11 November 2021 |work=ESO |accessdate=11 November 2021 }}</ref>

==Gallery==
<gallery mode=packed heights=240px>
File:NGC 1850.jpg|[[ESO]] image of NGC 1850 showing the stellar cluster and surrounding nebulosity
</gallery>

==References==
{{Reflist|refs=

<ref name=Westerlund1997>{{cite book
 | title=The Magellanic Clouds
 | first=Bengt E. | last=Westerlund
 | isbn=9780521480703 | date=February 27, 1997
 | publisher=Cambridge University Press
 | editor1-first=Andrew | editor1-last=King
 | editor2-first=Douglas | editor2-last=Lin
 | editor3-first=Jim | editor3-last=Pringle
 | editor4-first=Martin | editor4-last=Ward
 | editor5-first=Stephen | editor5-last=Maran
 | url=https://books.google.com/books?id=OSiPrgHFOYUC&pg=PA74
}}</ref>

<ref name=Fischer1993>{{cite journal
 | title=Dynamics of the Young Binary LMC Cluster NGC 1850
 | display-authors=1 | last1=Fischer | first1=Philippe
 | last2=Welch | first2=Douglas L. | last3=Mateo | first3=Mario
 | journal=Astronomical Journal
 | volume=105 | pages=938–944 | date=March 1993
 | doi=10.1086/116483 | arxiv=astro-ph/9210004
 | bibcode=1993AJ....105..938F | s2cid=119484423 }}</ref>

<ref name=Correnti2017>{{cite journal
 | title=Dissecting the extended main-sequence turn-off of the young star cluster NGC 1850
 | display-authors=1 | last1=Correnti | first1=Matteo
 | last2=Goudfrooij | first2=Paul | last3=Bellini | first3=Andrea
 | last4=Kalirai | first4=Jason S. | last5=Puzia | first5=Thomas H.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=467 | issue=3 | pages=3628–3641 | date=May 2017
 | doi=10.1093/mnras/stx010 | doi-access=free | arxiv=1612.08746
 | bibcode=2017MNRAS.467.3628C }}</ref>

<ref name=Caloi1998>{{cite journal
 | title=Evolutionary status and age spread in the young LMC cluster NGC 1850A
 | last1=Caloi | first1=V. | last2=Cassatella | first2=A.
 | journal=Astronomy and Astrophysics
 | volume=330 | pages=492–504 | date=February 1998
 | bibcode=1998A&A...330..492C }}</ref>

<ref name=Gilmozzi1994>{{cite journal
 | title=WFPC2 Observations of the Double Cluster NGC 1850 in the Large Magellanic Cloud
 | display-authors=1 | last1=Gilmozzi | first1=R.
 | last2=Kinney | first2=E. K. | last3=Ewald | first3=S. P.
 | last4=Panagia | first4=N. | last5=Romaniello | first5=M.
 | journal=Astrophysical Journal Letters
 | volume=435 | page=L43 | date=November 1994
 | doi=10.1086/187590 | bibcode=1994ApJ...435L..43G }}</ref>

<ref name=Werchan2011>{{cite journal
 | title=The Star Clusters of the Large Magellanic Cloud: Structural Parameters
 | last1=Werchan | first1=Felicia | last2=Zaritsky | first2=Dennis
 | journal=The Astronomical Journal
 | volume=142 | issue=2 | id=48 | pages=10 | date=August 2011
 | doi=10.1088/0004-6256/142/2/48 | arxiv=1105.1769
 | bibcode=2011AJ....142...48W | s2cid=118331608 }}</ref>

<ref name=gallagher02>{{cite conference
 | last1=Gallagher | first1=J. S. | last2=Grebel | first2=E. K.
 | title=Extragalactic Star Clusters: Speculations on the Future
 | conference=Extragalactic Star Clusters, IAU Symposium
 | publisher=Astronomical Society of the Pacific
 | editor1-first=D. | editor1-last=Geisler
 | editor2-first=E. K. | editor2-last=Grebel
 | editor3-first=D. | editor3-last=Minniti
 | volume=207 | page=745 | date=2002
 | bibcode=2002IAUS..207..745G | arxiv=astro-ph/0109052 }}</ref>

}}

== External links ==
* [https://apod.nasa.gov/apod/ap230220.html '''NGC 1850: Not Found in the Milky Way (Astronomy Picture of the Day)''']
* {{commonscat-inline}}

{{NGC20}}
{{Dorado}}

{{DEFAULTSORT:NGC 1850}}
[[Category:Globular clusters]]
[[Category:Open clusters]]
[[Category:Large Magellanic Cloud]]
[[Category:Dorado]]
[[Category:NGC objects|1850]]