View source for Messier 5

{{Short description|Globular cluster in the constellation Serpens}}
{{Infobox globular cluster
| name = Messier 5
| image = [[Image:M5s.jpg|300px]]
| caption = Globular cluster Messier 5 in Serpens
| credit = 
| epoch = [[J2000]]
| class = V<ref name=hcob849_11/>
| constellation = [[Serpens]]
| ra = {{RA|15|18|33.22}}<ref name=aj140_6_1830/>
| dec = {{DEC|+02|04|51.7}}<ref name=aj140_6_1830/>
| dist_ly = {{Convert|24.5|kly|kpc|abbr=on|lk=on}}<ref name=aj139_2_476/>
| appmag_v = 5.6<ref>{{cite web |url=http://www.messier.seds.org/m/m005.html |title=Messier 5 |access-date=21 July 2024 |website=SEDS Messier Catalog}}</ref>
| size_v = 23′.0
| mass_msol = {{Val|8.57|e=5}}<ref name=apj742_1_51/>
| radius_ly = 80&nbsp;ly
| v_hb = 
| metal_fe = –1.12<ref name=mnras404_3_1203/>
| age = 10.62&nbsp;[[Gigayear|Gyr]]<ref name=mnras404_3_1203/>
| notes = 
| names = [[New General Catalogue|NGC]] 5904, GCl 34<ref name="simbad"/>
}}
'''Messier 5''' or '''M5''' (also designated '''NGC 5904''') is a [[globular cluster]] in the [[constellation]] [[Serpens]]. It was discovered by [[Gottfried Kirch]] in 1702.

==Discovery and visibility==
M5 is, under extremely good conditions, just visible to the naked eye as a faint "star" 0.37 of a degree (22' ([[arcmin]])) north-west of [[star]] [[5 Serpentis]]. [[Binoculars]] and/or small [[telescope]]s resolve the object as non-stellar; larger telescopes will show some individual stars, some of which are as bright as [[apparent magnitude]] 10.6.<ref name="CouttsClement"/>
M5 was discovered by German astronomer [[Gottfried Kirch]] in 1702 when he was observing a [[comet]]. [[Charles Messier]] noted it in 1764 and—a studier of comets—cast it as one of his nebulae. [[William Herschel]] was the first to resolve individual stars in the cluster in 1791, counting roughly 200.<ref name="Herschel"/> Messier 5 is receding from the Solar System at a speed over 50 km/s.<ref>{{cite journal|doi=10.1086/118116|title=A Catalog of Parameters for Globular Clusters in the Milky Way|journal=The Astronomical Journal|volume=112|pages=1487|year=1996|last1=Harris|first1=William E.|bibcode=1996AJ....112.1487H}}</ref>

==Notable features==
One hundred and five stars in M5 are known to be [[variable star|variable]] in brightness, 97 of them belonging to the [[RR Lyrae variable|RR Lyrae]] type.<ref name="Szeidl">{{cite journal|doi=10.1111/j.1365-2966.2010.17815.x|title=Long-term photometric monitoring of Messier 5 variables – I. Period changes of RR Lyrae stars|journal=Monthly Notices of the Royal Astronomical Society|volume=411|issue=3|pages=1744–1762|year=2011|last1=Szeidl|first1=B.|last2=Hurta|first2=Zs.|last3=Jurcsik|first3=J.|last4=Clement|first4=C.|last5=Lovas|first5=M.|doi-access=free |bibcode=2011MNRAS.411.1744S|arxiv = 1010.1115 |s2cid=118519067}}</ref> RR Lyrae stars, sometimes referred to as ''"Cluster Variables"'', are somewhat similar to [[Cepheid variable|Cepheid type variables]] and as such can be used as a tool to measure distances in outer space since the relation between their luminosities and periods are well known. The brightest and most easily observed variable in M5 varies from magnitude 10.6 to 12.1 in a period of just under 26.5 days.<ref name="CouttsClement"/>

The cluster contains two [[millisecond pulsar]]s, one of which is in a binary, allowing the [[proper motion]] of the cluster to be measured. The binary could help our understanding of [[neutron degenerate matter]]; the current median mass, if confirmed, would exclude any "soft" [[equation of state]] for such matter.<ref name="Freire">{{Cite journal | doi = 10.1086/587832| title = A Massive Neutron Star in the Globular Cluster M5| journal = The Astrophysical Journal| volume = 679| issue = 2| pages = 1433–1442| year = 2008| last1 = Freire | first1 = P. C. C. | last2 = Wolszczan | first2 = A. | last3 = van den Berg | first3 = M. | last4 = Hessels | first4 = J. W. T. | bibcode = 2008ApJ...679.1433F|arxiv = 0712.3826 | s2cid = 118743395}}</ref> The cluster has been used to test for [[magnetic dipole moment]]s in neutrinos, which could shed light on some hypothetical particles such as the [[axion]].<ref name="Viaux">{{Cite journal | doi = 10.1051/0004-6361/201322004| title = Particle-physics constraints from the globular cluster M5: Neutrino dipole moments| journal = Astronomy & Astrophysics| volume = 558| pages = A12| year = 2013| last1 = Viaux | first1 = N.| last2 = Catelan | first2 = M.| last3 = Stetson | first3 = P. B.| last4 = Raffelt | first4 = G. G.| last5 = Redondo | first5 = J.| last6 = Valcarce | first6 = A. A. R.| last7 = Weiss | first7 = A.| bibcode = 2013A&A...558A..12V|arxiv = 1308.4627 | s2cid = 59056210}}</ref>

A [[dwarf nova]] has also been observed in this cluster.<ref name="Neill"/>

[[File:Messier 5 - HST.jpg|thumb|Messier 5 by [[Hubble Space Telescope]] – 2.85′ view]]
==See also==
* [[Messier object#Messier_objects|List of Messier objects]]

==References==
{{Reflist|refs=

<ref name=aj140_6_1830>{{citation | display-authors=1 | last1=Goldsbury | first1=Ryan | last2=Richer | first2=Harvey B. | last3=Anderson | first3=Jay | last4=Dotter | first4=Aaron | last5=Sarajedini | first5=Ata | last6=Woodley | first6=Kristin | title=The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters | journal=The Astronomical Journal | volume=140 | issue=6 | pages=1830–1837 |date=December 2010 | doi=10.1088/0004-6256/140/6/1830 | bibcode=2010AJ....140.1830G | postscript=. |arxiv = 1008.2755 | s2cid=119183070 }}</ref>

<ref name=hcob849_11>{{citation | last1=Shapley | first1=Harlow | last2=Sawyer | first2=Helen B. | title=A Classification of Globular Clusters | journal=Harvard College Observatory Bulletin | volume=849 | issue=849 | pages=11–14 |date=August 1927 | bibcode=1927BHarO.849...11S | postscript=. }}</ref>

<ref name=mnras404_3_1203>{{citation | last1=Forbes | first1=Duncan A. | last2=Bridges | first2=Terry | title=Accreted versus in situ Milky Way globular clusters | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=404 | issue=3 | pages=1203–1214 |date=May 2010 | doi=10.1111/j.1365-2966.2010.16373.x | doi-access=free | bibcode=2010MNRAS.404.1203F | postscript=. |arxiv = 1001.4289 | s2cid=51825384 }}</ref>

<ref name=aj139_2_476>{{citation | display-authors=1 | last1=Paust | first1=Nathaniel E. Q. | last2=Reid | first2=I. Neill | last3=Piotto | first3=Giampaolo | last4=Aparicio | first4=Antonio | last5=Anderson | first5=Jay | last6=Sarajedini | first6=Ata | last7=Bedin | first7=Luigi R. | last8=Chaboyer | first8=Brian | last9=Dotter | first9=Aaron | last10=Hempel | first10=Maren | last11=Majewski | first11=Steven | last12=Marín-Franch | first12=A. | last13=Milone | first13=Antonino | last14=Rosenberg | first14=Alfred | last15=Siegel | first15=Michael | title=The ACS Survey of Galactic Globular Clusters. VIII. Effects of Environment on Globular Cluster Global Mass Functions | journal=The Astronomical Journal | volume= 139 | issue= 2 | pages= 476–491 |date=February 2010 | doi=10.1088/0004-6256/139/2/476 | bibcode=2010AJ....139..476P | postscript=. | hdl=2152/34371 | s2cid=120965440 | hdl-access=free }}</ref>

<ref name="simbad">{{cite simbad | title=M 5 | accessdate=2006-11-15}}</ref>

<ref name=apj742_1_51>{{citation | display-authors=1 | last1=Boyles | first1=J. | last2=Lorimer | first2=D. R. | last3=Turk | first3=P. J. | last4=Mnatsakanov | first4=R. | last5=Lynch | first5=R. S. | last6=Ransom | first6=S. M. | last7=Freire | first7=P. C. | last8=Belczynski | first8=K. | title=Young Radio Pulsars in Galactic Globular Clusters | journal=The Astrophysical Journal | volume=742 | issue=1 | page=51 |date=November 2011 | doi=10.1088/0004-637X/742/1/51 | bibcode=2011ApJ...742...51B | postscript=. |arxiv = 1108.4402 | s2cid=118649860 }}</ref>

<ref name="CouttsClement">{{cite journal |last1=Coutts Clement |first1=Christine M. |last2=Sawyer Hogg |first2=Helen |title=The Bright Variable Stars in Messier 5 |journal=Journal of the Royal Astronomical Society of Canada |date=August 1977 |volume=71 |page=281 |bibcode=1977JRASC..71..281C |url=https://ui.adsabs.harvard.edu/abs/1977JRASC..71..281C |access-date=1 March 2021}}</ref>

<ref name="Herschel">{{cite web |title=William Herschel's Observations of the Messier Objects |url=https://www.messier.seds.org/xtra/history/her-obsm.html |website=www.messier.seds.org |publisher=Students for the Exploration and Development of Space |access-date=1 March 2021 |archive-date=24 June 2021 |archive-url=https://web.archive.org/web/20210624091741/https://www.messier.seds.org/xtra/history/her-obsm.html |url-status=dead }}</ref>

<ref name="Neill">{{cite journal |last1=Neill |first1=James D. |last2=Shara |first2=Michael M. |last3=Caulet |first3=Adeline |last4=Buckley |first4=David A.H. |title=The first orbital period for a dwarf nova in a globular cluster: V101 in M5 |journal=The Astronomical Journal |date=June 2002 |volume=123 |issue=6 |pages=3298–3304 |doi=10.1086/340469 |doi-access=free |arxiv=astro-ph/0203138 }}</ref>

}}

== External links ==
{{Commons category|Messier 5}}
* [http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=M5 SIMBAD: M5]
* [http://www.messier.seds.org/m/m005.html M5, SEDS Messier pages]
* [http://gclusters.altervista.org/cluster_4.php?ggc=M+5 M5, Galactic Globular Clusters Database page]
* [http://messier.seds.org/Mdes/dm005.html Historic observations of M5]
* [http://www.waid-observatory.com/m005-2006-04-17.html Image of M5 by Waid Observatory]
* {{WikiSky}}
{{Sky|15|18|33.75||02|04|57.7|24500}}

{{Portal bar|Astronomy|Stars|Outer space}}
{{Catalogs|NGC=5904|M=5}}
{{Messier objects}}
{{Ngc60}}
{{Serpens}}

{{DEFAULTSORT:Messier 5}}
[[Category:Globular clusters|Messier 005]]
[[Category:Serpens|Messier 005]]
[[Category:NGC objects|Messier 005]]
[[Category:Messier objects|005]]
[[Category:Astronomical objects discovered in 1702|17020505]]