View source for Messier 52

{{short description|Open cluster in the constellation Cassiopeia}}
{{Infobox open cluster
 | name      = [[Messier object|Messier]] 52
 | image     = [[Image:M52atlas.jpg|300px]]
 | caption   = Open cluster Messier 52 in Cassiopeia
 | credit    = 
 | epoch     = [[J2000]]
 | class     = 
 | constellation = [[Cassiopeia (constellation)|Cassiopeia]]
 | ra        = {{RA|23|24|48.0}}<ref name=Wu2009/>
 | dec       = {{Dec|+61|35|36}}<ref name=Wu2009/>
 | dist_ly   = {{cvt|1.4|kpc|kly|order=flip|lk=on}}<ref name=Wu2009/>
 | dist_pc   =
 | appmag_v  = 7.3<ref>{{cite web |url=https://messier.seds.org/m/m052.html |title=Messier 52 |access-date=29 April 2022 |website=SEDS Messier Catalog |archive-date=1 July 2022 |archive-url=https://web.archive.org/web/20220701070529/http://www.messier.seds.org/m/m052.html |url-status=dead }}</ref>
 | size_v    = {{Val|13.0|ul=arcminute}}<ref name=Adam2018/>
 | mass_msol = {{Val|1200|ul=solar mass|fmt=commas}}<ref name=Bonatto2006/>
 | radius_ly = {{Val|9.5|u=ly}}<ref name=Adam2018/>
 | age       = 158.5&nbsp;Myr<ref name=Wu2009/>
 | notes     =
 | names     = [[New General Catalogue|NGC]] 7654, [[Collinder catalogue|Cr]] 455, C&nbsp;2322+613, OCl&nbsp;260<ref name=SIMBAD/>
}}

'''Messier 52''' or '''M52''', also known as '''NGC 7654''' or the '''Scorpion Cluster''', is an [[open cluster]] of [[star]]s in the highly northern [[constellation]] of [[Cassiopeia (constellation)|Cassiopeia]]. It was discovered by [[Charles Messier]] in 1774.<ref name=Adam2018/>{{efn|September 7}} It can be seen from [[Earth]] under [[light pollution|a good night sky]] with [[binoculars]]. The brightness of the cluster is influenced by [[extinction (astronomy)|extinction]], which is stronger in the southern half.<ref name=Pandey2001/> Its [[metallicity]] is somewhat below that of the [[Sun]], and is estimated to be [Fe/H] = −0.05 ± 0.01.<ref name=Akbulut/>

[[Robert Julius Trumpler|R. J. Trumpler]] [[Trumpler classification|classified]] the cluster appearance as II2r, indicating a rich cluster with little central concentration and a medium range in the brightness of the stars.<ref name=Trumpler1930/> This was later revised to I2r, denoting a dense core.<ref name=Pandey2001/> The cluster has a core radius of {{cvt|0.91|±|0.14|pc|ly|order=flip}} and a [[Tidal radius (cluster)|tidal radius]] of {{Convert|13.1|±|2.2|pc|ly|order=flip|abbr=on}}.<ref name=Bonatto2006/> It has an estimated age of 158.5&nbsp;million years<ref name=Wu2009/> and a mass of {{Val|1200|ul=solar mass|fmt=commas}}.<ref name=Bonatto2006/>

The magnitude 8.3 supergiant star BD +60°2532 is a probable member of the cluster,<ref name=Bonatto2006/> so too 18 candidate [[slowly pulsating B star]]s, one being a [[Delta Scuti variable|Delta (δ) Scuti variable]], and three candidate [[Gamma Doradus variable|Gamma Doradus (γ Dor) variables]].<ref name=Luo2012/> There may also be three [[Be star]]s.<ref name=Bond1973/> The core of the cluster shows a lack of interstellar matter, which may be due to [[supernova]]e explosion(s) early in the cluster's history.<ref name=Pandey2001/>

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

== References and footnotes ==
{{Reflist|refs=

<ref name=SIMBAD>{{cite simbad | title=M 52 | access-date=November 28, 2018 }}</ref>

<ref name=Bond1973>{{citation
 | title=Be Stars in the Galactic Cluster M 52
 | last1=Bond | first1=Howard E. | postscript=.
 | journal=Publications of the Astronomical Society of the Pacific
 | volume=85 | issue=506 | page=405 | date=August 1973
 | doi=10.1086/129477 | bibcode=1973PASP...85..405B | doi-access=free }}</ref>

<ref name=Pandey2001>{{citation
 | title=NGC 7654: An interesting cluster to study star formation history
 | last1=Pandey | first1=A. K. | last2=Nilakshi
 | last3=Ogura | first3=K. | last4=Sagar | first4=Ram
 | last5=Tarusawa | first5=K. | display-authors=1
 | journal=Astronomy and Astrophysics | postscript=.
 | volume=374 | issue=2 | pages=504–522 | date=August 2001
 | doi=10.1051/0004-6361:20010642 | bibcode=2001A&A...374..504P | doi-access=free }}</ref>

<ref name=Adam2018>{{citation
 | title=Imaging the Messier Objects Remotely from Your Laptop
 | series=The Patrick Moore Practical Astronomy Series
 | first1=Len | last1=Adam | publisher=Springer
 | year=2018 | isbn=978-3319653853 | page=241
 | url=https://books.google.com/books?id=7nNUDwAAQBAJ&pg=PA241 | bibcode=2018imor.book.....A
 }}</ref>

<ref name=Trumpler1930>{{citation
 | title=Preliminary results on the distances, dimensions and space distribution of open star clusters
 | last1=Trumpler | first1=Robert Julius
 | journal=Lick Observatory Bulletin
 | volume=420 | pages=154–188 | year=1930
 | doi=10.5479/ADS/bib/1930LicOB.14.154T
 | bibcode=1930LicOB..14..154T | postscript=. | doi-access=free}}</ref>

<ref name=Bonatto2006>{{citation
 | title=Methods for improving open cluster fundamental parameters applied to M 52 and NGC 3960
 | last1=Bonatto | first1=C. | last2=Bica | first2=E.
 | journal=Astronomy and Astrophysics
 | volume=455 | issue=3 | date=September 2006 | pages=931–942
 | doi=10.1051/0004-6361:20065315 | bibcode=2006A&A...455..931B | arxiv=astro-ph/0608022 | s2cid=16118935 }}</ref>

<ref name=Luo2012>{{citation | postscript=.
 | last1=Luo | first1=Y. P. | last2=Zhang | first2=X. B.
 | last3=Deng | first3=L. C. | last4=Han | first4=Z. W.
 | title=Discovery of 14 New Slowly Pulsating B Stars in the Open Cluster NGC 7654
 | journal=The Astrophysical Journal Letters | display-authors=1
 | volume=746 | issue=1 | id=L7 | pages=5 | date=February 2012
 | doi=10.1088/2041-8205/746/1/L7 | bibcode=2012ApJ...746L...7L | doi-access=free }}</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
 | doi=10.1111/j.1365-2966.2009.15416.x | doi-access=free | postscript=.
 | bibcode=2009MNRAS.399.2146W | arxiv=0909.3737 | s2cid=6066790 }}</ref>

<ref name=Akbulut>{{cite journal
 | doi=10.1007/s10509-021-03975-x
 | title=A study of the Czernik 2 and NGC 7654 open clusters using CCD UBV photometric and Gaia EDR3 data
 | year=2021 | last1=Akbulut | first1=B. | last2=Ak | first2=S.
 | last3=Yontan | first3=T. | last4=Bilir | first4=S.
 | last5=Ak | first5=T. | last6=Banks | first6=T.
 | last7=Kaan Ulgen | first7=E. | last8=Paunzen | first8=E.
 | journal=Astrophysics and Space Science | volume=366 | issue=7
 | arxiv=2107.03462 | s2cid=235765696}}</ref>

}}
{{notelist}}

==External links==
* {{commonscat-inline}}
* [http://messier.seds.org/m/m052.html Messier 52, SEDS Messier pages]
* {{WikiSky|NGC 7654}}

{{Sky|23|24.2|00|+|61|35|00|5000}}
{{Portal bar|Astronomy|Stars|Outer space}}
{{Messier objects}}
{{catalogs|M=52|NGC=7654}}
{{Ngc80}}
{{Cassiopeia (constellation)}}

[[Category:Open clusters|Messier 052]]
[[Category:Cassiopeia (constellation)|Messier 052]]
[[Category:Messier objects|052]]
[[Category:NGC objects|Messier 052]]
[[Category:Perseus Arm]]
[[Category:Astronomical objects discovered in 1774|?]]
[[Category:Discoveries by Charles Messier]]