{{Short description|Globular cluster in the constellation Boötes}} {{Infobox globular cluster | name = NGC 5466 | image = [[File:NGC 5466 Hubble WikiSky.jpg|275px]] | caption = NGC 5466 by [[Hubble Space Telescope]]; 3.5{{prime}} view | credit = | epoch = [[J2000]] | class = XII<ref name=hcob849_11/> | constellation = [[Boötes]] | ra = {{RA|14|05|27.29}}<ref name=aj140_6_1830/> | dec = {{DEC|+28|32|04.0}}<ref name=aj140_6_1830/> | dist_ly = | dist_pc ={{Cvt|16.0|±|0.4|kpc|kly|order=flip|lk=on}}<ref name=Jensen_et_al_2021/> | appmag_v = 9.2<ref name=Thompson_104/> | size_v = {{val|9.0|u=arcminute}}<ref name=Thompson_104/> | absmag_v = −6.98<ref name=Jensen_et_al_2021/> | mass_msol = {{Val|1.79|e=5}}<ref name=apj742_1_51/> | mass_kg = | radius_arcminsec = | radius_ly = | radius_pc = | radius_tidal_arcminsec = | radius_tidal_ly = {{cvt|72.98|pc|ly|order=flip}}<ref name=Jensen_et_al_2021/> | radius_tidal_pc = | v_hb = 16.47 | metal_fe = –1.95{{±|0.02}}<ref name=Gontcharov_et_al_2024/> | metal_z = | age = 12.15{{±|0.11}} [[Gigayear|Gyr]]<ref name=Gontcharov_et_al_2024/> | notes = Tidal stream | names = [[New General Catalogue|NGC]] 5466, C 1403+287, GCl 27, [[General Catalogue of Nebulae and Clusters|GC]] 3776, [[List of astronomical catalogues#H|h]] 1746, H 6<ref name=SIMBAD/> }}
'''NGC 5466''' is a [[globular cluster]] of stars in the [[Boötes constellation|constellation Boötes]]. It was discovered by German-British astronomer [[William Herschel]] on May 17, 1784, and catalogued as H VI.9.<ref name=Steinicke_2021/> This large, dim cluster has an [[apparent visual magnitude]] of 9.2 and spans an [[angular size]] of {{val|9.0|u=arcminute}}.<ref name=Thompson_104/> It is relatively distant from the [[Sun]],<ref name=Jensen_et_al_2021/> about {{convert|16.0|kpc|e3ly|order=flip|lk=on|abbr=out}} away,<ref name=Jensen_et_al_2021/><ref name=Arellano_Ferro_et_al_2008/> and {{convert|16.3|kpc|e3ly|order=flip|abbr=out}} from the [[Galactic Center]].<ref name=Lux_et_al_2012/>
==Observations== The [[Shapley–Sawyer Concentration Class]] of NGC 5466 is XII.<ref name=hcob849_11/> This is a loose cluster with an unusually low central density compared to other globulars with similar luminosity.<ref name=Fekadu_et_al_2007/> It is located at a high galactic latitude and thus displays negligible [[Extinction (astronomy)|reddening]] from [[interstellar dust]].<ref name=Fekadu_et_al_2007/> The cluster has a core radius of {{val|1.43|0.10|u=arcminute}} and a half-light radius of {{val|2.3|0.07|u=arcminute}}. The King tidal radius is {{cvt|72.98|pc|ly|order=flip}}.<ref name=Jensen_et_al_2021/>
Observation of the distribution of stars in the cluster shows the impact of mass segregation, with heavier objects sinking toward the center. This is a dynamically young cluster that is just starting to evolve.<ref name=Beccari_et_al_2015/> An [[Stellar isochrone|isochrone]] fit to the cluster yields an age estimate of 12.15{{±|0.11}} billion years.<ref name=Gontcharov_et_al_2024/> Other age estimates range from 12.2{{±|0.9}} to 13.57 Gyr, depending on the method.<ref name=Arellano_Ferro_et_al_2008/><ref name=mnras404_3_1203/> It has an extremely low [[metallicity]].<ref name=Gontcharov_et_al_2024/>
In 2006, a long [[Tidal stream (astrophysics)|tidal stream]] was detected stretching from this cluster,<ref name=Belokurov_et_al_2006/> perhaps reaching as far as {{val|45|to|60|u=°}} across the sky.<ref name=Grillmair_Johnson_2006/><ref name=Yang_et_al_2022/> It has a combined mass estimated as {{val|4.0|e=3|ul=solar mass}}.<ref name=Jensen_et_al_2021/> The width dispersion of the stream is {{val|1.31|0.24|u=°}}, corresponding to a physical width of {{cvt|367|±|67|pc|ly|order=flip}} at the distance of the cluster.<ref name=Jensen_et_al_2021/> The presence of a tidal tail suggests the cluster has been strongly disrupted due to gravitational interactions with the [[Milky Way]] galaxy.<ref name=Fekadu_et_al_2007/> At some point, this stream may have been tidally disrupted by the [[Large Magellanic Cloud]].<ref name=Yang_et_al_2022/>
A total of 97 [[blue straggler]] stars have been identified in this cluster, which show a mild central peak in distribution.<ref name=Beccari_et_al_2013/> In 2019, it was reported that a candidate hot [[white dwarf]] had been discovered orbiting a [[blue straggler]] star in the outskirts of NGC 5466. This was the second such pair discovered in a globular cluster.<ref name=Sahu_et_al_2019/> Three short period [[eclipsing binaries]] have been found along with six [[SX Phoenicis variable]]s.<ref name=Mateo_et_al_1990/><ref name=Jeon_et_al_2004/> This was the first globular where a blue straggler eclipsing variable was found.<ref name=Beccari_et_al_2015/> The cluster is host to the brightest-known anomalous [[Cepheid variable]], designated V19.<ref name=McCarthy_Nemec_1997/><ref name=Zinn_King_1982/>
==Gallery== <gallery> NGC5466Location.png|The location of NGC 5466 (circled in red) N5466s.jpg|NGC 5466 imaged with a 32-inch telescope </gallery>
==See also== * [[List of stellar streams]]
==References== <references> <ref name=SIMBAD>{{cite simbad | title=NGC 5466 | access-date=2025-03-15 | postscript=. | mode = cs2 }}</ref>
<ref name=aj140_6_1830>{{citation | postscript=. | title=The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters | 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 | display-authors=1 | journal=The Astronomical Journal | volume=140 | issue=6 | pages=1830–1837 | date=December 2010 | doi=10.1088/0004-6256/140/6/1830 | arxiv=1008.2755 | bibcode=2010AJ....140.1830G | s2cid=119183070 }}</ref>
<ref name=hcob849_11>{{citation | postscript=. | title=A Classification of Globular Clusters | last1=Shapley | first1=Harlow | last2=Sawyer | first2=Helen B. | journal=Harvard College Observatory Bulletin | volume=849 | issue=849 | pages=11–14 |date=August 1927 | bibcode=1927BHarO.849...11S }}</ref>
<ref name=mnras404_3_1203>{{citation | postscript=. | title=Accreted versus in situ Milky Way globular clusters | last1=Forbes | first1=Duncan A. | last2=Bridges | first2=Terry | 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 |arxiv = 1001.4289 | s2cid=51825384 }}</ref>
<ref name=apj742_1_51>{{citation | postscript=. | title=Young Radio Pulsars in Galactic Globular Clusters | 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. | display-authors=1 | journal=The Astrophysical Journal | volume=742 | issue=1 | page=51 | date=November 2011 | doi=10.1088/0004-637X/742/1/51 | arxiv=1108.4402 | bibcode=2011ApJ...742...51B | s2cid=118649860 }}</ref>
<ref name=Gontcharov_et_al_2024>{{citation | postscript=. | title=Isochrone Fitting of Galactic Globular Clusters—VI. High-latitude Clusters NGC 5024 (M53), NGC 5053, NGC 5272 (M3), NGC 5466, and NGC 7099 (M30) | last1=Gontcharov | first1=G. A. | last2=Savchenko | first2=S. S. | last3=Marchuk | first3=A. A. | last4=Bonatto | first4=C. J. | last5=Ryutina | first5=O. S. | last6=Khovritchev | first6=M. Yu. | last7=Il'in | first7=V. B. | last8=Mosenkov | first8=A. V. | last9=Poliakov | first9=D. M. | last10=Smirnov | first10=A. A. | journal=Research in Astronomy and Astrophysics | volume=24 | issue=6 | at=id .065014 | date=June 2024 | doi=10.1088/1674-4527/ad420f | arxiv=2404.14797 | bibcode=2024RAA....24f5014G | display-authors=1 }}</ref>
<ref name=Yang_et_al_2022>{{citation | postscript=. | title=Revisit NGC 5466 tidal stream with Gaia, SDSS/SEGUE, and LAMOST | last1=Yang | first1=Yong | last2=Zhao | first2=Jing-Kun | last3=Ishigaki | first3=Miho N. | last4=Zhou | first4=Jian-Zhao | last5=Yang | first5=Cheng-Qun | last6=Xue | first6=Xiang-Xiang | last7=Ye | first7=Xian-Hao | last8=Zhao | first8=Gang | journal=Monthly Notices of the Royal Astronomical Society | volume=513 | issue=1 | pages=853–863 | date=June 2022 | doi=10.1093/mnras/stac860 | doi-access=free | arxiv=2203.13414 | bibcode=2022MNRAS.513..853Y | display-authors=1 }}</ref>
<ref name=Jensen_et_al_2021>{{citation | postscript=. | title=Uncovering fossils of the distant Milky Way with UNIONS: NGC 5466 and its stellar stream | last1=Jensen | first1=Jaclyn | last2=Thomas | first2=Guillaume | last3=McConnachie | first3=Alan W. | last4=Starkenburg | first4=Else | last5=Malhan | first5=Khyati | last6=Navarro | first6=Julio | last7=Martin | first7=Nicolas | last8=Famaey | first8=Benoit | last9=Ibata | first9=Rodrigo | last10=Chapman | first10=Scott | last11=Cuillandre | first11=Jean-Charles | last12=Gwyn | first12=Stephen | journal=Monthly Notices of the Royal Astronomical Society | volume=507 | issue=2 | pages=1923–1936 | date=October 2021 | doi=10.1093/mnras/stab2325 | doi-access=free | arxiv=2108.04340 | bibcode=2021MNRAS.507.1923J | display-authors=1 }}</ref>
<ref name=Sahu_et_al_2019>{{citation | postscript=. | title=Detection of a White Dwarf Companion to a Blue Straggler Star in the Outskirts of Globular Cluster NGC 5466 with the Ultraviolet Imaging Telescope (UVIT) | last1=Sahu | first1=Snehalata | last2=Subramaniam | first2=Annapurni | last3=Simunovic | first3=Mirko | last4=Postma | first4=J. | last5=Côté | first5=Patrick | last6=Kameswera Rao | first6=N. | last7=Geller | first7=Aaron M. | last8=Leigh | first8=Nathan | last9=Shara | first9=Michael | last10=Puzia | first10=Thomas H. | last11=Stetson | first11=Peter B. | display-authors=1 | journal=The Astrophysical Journal | volume=876 | issue=1 | at=id. 34 | date=May 2019 | doi=10.3847/1538-4357/ab11d0 | doi-access=free | arxiv=1903.08212 | bibcode=2019ApJ...876...34S }}</ref>
<ref name=Beccari_et_al_2015>{{citation | postscript=. | title=Deep Multi-telescope Photometry of NGC 5466. II. The Radial Behavior of the Mass Function Slope | last1=Beccari | first1=G. | last2=Dalessandro | first2=E. | last3=Lanzoni | first3=B. | last4=Ferraro | first4=F. R. | last5=Bellazzini | first5=M. | last6=Sollima | first6=A. | display-authors=1 | journal=The Astrophysical Journal | volume=814 | issue=2 | at=id. 144 | date=December 2015 | doi=10.1088/0004-637X/814/2/144 | arxiv=1511.00829 | bibcode=2015ApJ...814..144B }}</ref>
<ref name=Beccari_et_al_2013>{{citation | postscript=. | title=Deep Multi-telescope Photometry of NGC 5466. I. Blue Stragglers and Binary Systems | last1=Beccari | first1=G. | last2=Dalessandro | first2=E. | last3=Lanzoni | first3=B. | last4=Ferraro | first4=F. R. | last5=Sollima | first5=A. | last6=Bellazzini | first6=M. | last7=Miocchi | first7=P. | display-authors=1 | journal=The Astrophysical Journal | volume=776 | issue=1 | at=id. 60 | date=October 2013 | doi=10.1088/0004-637X/776/1/60 | arxiv=1308.5810 | bibcode=2013ApJ...776...60B }}</ref>
<ref name=Fekadu_et_al_2007>{{citation | postscript=. | title=Photometry of the Globular Cluster NGC 5466: Red Giants and Blue Stragglers | display-authors=1 | last1=Fekadu | first1=Nassissie | last2=Sandquist | first2=Eric L. | last3=Bolte | first3=Michael | journal=[[The Astrophysical Journal]] | volume=663 | pages=277–295 | issue=1 | year=2007 | doi=10.1086/518637 | arxiv=astro-ph/0602602 | bibcode=2007ApJ...663..277F | s2cid= 2600674}}</ref>
<ref name=Arellano_Ferro_et_al_2008>{{citation | postscript=. | title=CCD photometry of the globular cluster NGC 5466. RR Lyrae light-curve decomposition and the distance scale | last1=Arellano Ferro | first1=A. | last2=Rojas López | first2=V. | last3=Giridhar | first3=Sunetra | last4=Bramich | first4=D. M. | journal=Monthly Notices of the Royal Astronomical Society | volume=384 | issue=4 | pages=1444–1458 | year=2008 | bibcode=2008MNRAS.384.1444A | arxiv=0711.4027 | doi=10.1111/j.1365-2966.2007.12760.x | doi-access=free | s2cid=17346022 | display-authors=1 }}</ref>
<ref name=Belokurov_et_al_2006>{{citation | postscript=. | display-authors=1 | last1=Belokurov | first1=V. | last2=Evans | first2=N. W. | last3=Irwin | first3=M. J. | last4=Hewett | first4=P. C. | last5=Wilkinson | first5=M. I. | title=The discovery of tidal tails around the globular cluster NGC 5466 | journal=[[The Astrophysical Journal]] | volume=637 | issue=1 | pages=L29–L32 | year=2006 | bibcode=2006ApJ...637L..29B | arxiv=astro-ph/0511767 | doi=10.1086/500362 | s2cid=125827556 }}</ref>
<ref name=Grillmair_Johnson_2006>{{citation | postscript=. | title=The detection of a 45° tidal stream associated with the globular cluster NGC 5466 | last1=Grillmair | first1=C. J. | last2=Johnson | first2=R. | journal=[[The Astrophysical Journal]] | volume=639|issue=1|pages=L17–L20|date=2006 | doi=10.1086/501439 | arxiv=astro-ph/0602602 | bibcode=2006ApJ...639L..17G | s2cid=17925570 }}</ref>
<ref name=Jeon_et_al_2004>{{citation | postscript=. | title=SX Phoenicis stars in the globular cluster NGC 5466 | last1=Jeon | first1=Young-Beom | last2=Lee | first2=Myung Gyoon | last3=Kim | first3=Seung-Lee | last4=Lee | first4=Ho | display-authors=1 | journal=[[The Astronomical Journal]] | volume=128 | issue=1 | pages=287–299 | year=2004 | doi=10.1086/421735 | arxiv=astro-ph/0404069 | bibcode=2004AJ....128..287J | s2cid=17310076 }}</ref>
<ref name=McCarthy_Nemec_1997>{{citation | postscript=. | title=The chemical composition and period change rate of the anomalous cepheid V19 in NGC 5466 | last1=McCarthy | first1=James K. | last2=Nemec | first2=James M. | journal=[[The Astrophysical Journal]] | volume=482 | issue=1 | pages=203–229 | year=1997 | bibcode=1997ApJ...482..203M | doi=10.1086/304118 | doi-access=}}</ref>
<ref name=Mateo_et_al_1990>{{citation | postscript=. | title=Blue stragglers as remnants of stellar mergers: the discovery of short-period eclipsing binaries in globular cluster NGC 5466 | last1=Mateo | first1=Mario | last2=Harris | first2=Hugh C. | last3=Nemec | first3=James | last4=Olszewski | first4=Edward W. | display-authors=1 | journal=[[The Astrophysical Journal]] | volume=100 | pages=469–484 | year=1990 | doi=10.1086/115530 | doi-access=free | bibcode=1990AJ....100..469M }}</ref>
<ref name=Zinn_King_1982>{{citation | postscript=. | title=The mass of the anomalous Cepheid in the globular cluster NGC 5466 | last1=Zinn | first1=R. | last2=King | first2=C. R. | journal=[[The Astrophysical Journal]] | volume=262 | pages=700–708 | year=1982 | bibcode=1982ApJ...262..700Z | doi=10.1086/160462 | doi-access=free }}</ref>
<ref name=Steinicke_2021>{{citation | postscript=. | title=Wiliam Herschel: Discoverer of the Deep Sky | first=Wolfgang | last=Steinicke | isbn=9783754397374 | page=149 | publisher=Books on Demand | year=2021 | url=https://books.google.com/books?id=8A5IEAAAQBAJ&pg=PA149 }}</ref>
<ref name=Thompson_104>{{citation | postscript=. | title=Illustrated Guide to Astronomical Wonders: From Novice to Master Observer | first1=Robert Bruce | last1=Thompson | first2=Barbara | last2=Thompson | series=DIY science | publisher=O'Reilly Media, Inc. | isbn=9780596526856 | page=104 | year=2007 | url=https://books.google.com/books?id=ymt9nj_uPhwC&pg=PA104 }}</ref>
<ref name=Lux_et_al_2012>{{citation | postscript=. | title=NGC 5466: a unique probe of the Galactic halo shape | last1=Lux | first1=H. | last2=Read | first2=J. I. | last3=Lake | first3=G. | last4=Johnston | first4=K. V. | journal=Monthly Notices of the Royal Astronomical Society: Letters | volume=424 | issue=1 | pages=L16–L20 | date=July 2012 | doi=10.1111/j.1745-3933.2012.01276.x | doi-access=free | arxiv=1204.5771 | bibcode=2012MNRAS.424L..16L }}</ref> </references>
==Further reading== {{Div col|small=yes}} * {{citation | postscript=. | title=Physical parameters of RR Lyrae stars in the globular cluster NGC 5466: The Oosterhoff dichotomy | last1=Rojas López | first1=V. | last2=Arellano Ferro | first2=A. | last3=Giridhar | first3=S. | last4=Bramich | first4=D. M. | work=XI IAU Regional Latin American Meeting of Astronomy | series=Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias) | editor1-first=L. | editor1-last=Infante | editor2-first=M. | editor2-last=Rubio | volume=26 | page=49 | year=2006 | bibcode=2006RMxAC..26...49R | display-authors=1 }} * {{citation | postscript=. | title=The giant, asymptotic and horizontal branches of globular clusters. II. Photographic of the metal-poor clusters M 15, M 92 and NGC 5466 | display-authors=1 | last1=Buonanno | first1=R. | last2=Corsi | first2=C. E. | last3=Fusi Pecci | first3=F. | journal=[[Astronomy & Astrophysics]] | volume=145 | pages=97–117 | year=1985 | bibcode=1985A&A...145...97B}} * {{citation | postscript=. | title=Positions, magnitudes and colors for stars in the globular cluster NGC 5466 | display-authors=1 | first1=Buonanno | last1=R. | last2=Buscema | first2=G. | last3=Corsi | first3=C. E. | last4=Iannicola | first4=G. | last5=Fusi Pecci | first5=F. | journal=[[Astronomy & Astrophysics]] | volume=56 | pages=79–86 | year=1984 | bibcode=1984A&AS...56...79B }} * {{citation | postscript=. | title=Membership of above horizontal branch stars in the globular cluster NGC 5466 | last1=Brosche | first1=P. | last2=Geffert | first2=M. | journal=[[Astronomy & Astrophysics]] | volume=127 | pages=415–416 | year=1983 | bibcode=1983A&A...127..415B }} {{Div col end}}
==External links== {{commons category}} *{{Sky-Map.org}} * VizieR, [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?NGC%205466 NGC 5466] * SEDS, [https://web.archive.org/web/20070510134210/http://www.seds.org/~spider/spider/MWGC/n5466.html NGC 5466] * Aladin, [http://aladin.u-strasbg.fr/AladinPreview?-c=14+05+27.36%2B28+32+04.2&ident=NGC++5466&submit=Aladin+previewer Image NGC 5466]
{{NGC objects:5000-5499}} {{Boötes}}
{{Sky|14|05|27.36|+|28|32|04.2|51800}}
{{DEFAULTSORT:Ngc 5466}} [[Category:Boötes]] [[Category:Globular clusters]] [[Category:NGC objects|5466]] [[Category:Stellar streams|45 Degree Tidal Stream]]