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{{short description|Constellation in the northern hemisphere}}
{{other uses}}
{{good article}}

{{Infobox constellation
| name = Coma Berenices
| abbreviation = Com
| genitive = Comae Berenices
| pronounce = {{IPAc-en|ˈ|k|oʊ|m|ə|_|b|ɛr|ə|ˈ|n|aɪ|s|iː|z}},<br>genitive {{IPAc-en|ˈ|k|oʊ|m|iː}}
| symbolism = [[Berenice II of Egypt|Berenice]]'s [[hair]]
| RA = {{RA|11|58|25.0885}}–{{RA|13|36|06.9433}}<ref name=boundary>{{Cite journal | title=Coma Berenices, constellation boundary | journal=The Constellations | publisher=International Astronomical Union|url=http://www.iau.org/public/constellations/#com | access-date=27 February 2014 }}</ref>
| dec= {{dec|33.3074303}}–{{dec|13.3040485}}<ref name=boundary/>
| family = [[Ursa Major Family|Ursa Major]]
| areatotal = 386
| arearank = 42nd
| numbermainstars = 3
| numberbfstars = 44
| numberbrightstars = 0
| numbernearbystars = 1
| brighteststarname = [[Beta Comae Berenices|β Com]]
| starmagnitude = 4.26
| neareststarname = [[Beta Comae Berenices|β Com]]<ref name=Kirkpatrick2024/>{{rp|84}}
| stardistancely = 30.00
| stardistancepc = 9.20
| numbermessierobjects = 8
| meteorshowers = [[Coma Berenicids]]
| bordering = [[Canes Venatici]]<br />[[Ursa Major]]<br />[[Leo (constellation)|Leo]]<br />[[Virgo (constellation)|Virgo]]<br />[[Boötes]]
| latmax = [[North Pole|90]]
| latmin = [[70th parallel south|70]]
| month = May
| notes=}}

'''Coma Berenices''' is an ancient [[asterism (astronomy)|asterism]] in the [[Northern celestial hemisphere|northern sky]], which has been defined as one of the [[IAU designated constellations|88]] modern [[constellation]]s. It is in the direction of the fourth [[galactic quadrant]], between [[Leo (constellation)|Leo]] and [[Boötes]], and it is visible in both hemispheres. Its name means "Berenice's Hair" in [[Latin]] and refers to Queen [[Berenice II of Egypt]], who sacrificed her long hair as a [[votive offering]].<ref>{{Cite American Heritage Dictionary|Coma Berenices}}</ref> It was introduced to Western astronomy during the third century BC by [[Conon of Samos]] and was further corroborated as a constellation by [[Gerardus Mercator]] and [[Tycho Brahe]]. It is the only [[88 modern constellations|modern constellation]] named after a historic person.{{efn|1=One other constellation's name is ''derived'' from a reference to a historical person: the constellation [[Scutum (constellation)|Scutum]] is a shortening of the former name ''Scutum Sobiescianum'' ("shield of Sobieski"), named after King [[John III Sobieski]] of Poland. It is called the equivalent of "Shield of Sobieski" in some other languages, such as French.}}

The constellation's major stars are [[Alpha Comae Berenices|Alpha]], [[Beta Comae Berenices|Beta]], and [[Gamma Comae Berenices]]. They form a half square, along the diagonal of which run Berenice's imaginary tresses, formed by the [[Coma Star Cluster]]. The constellation's brightest star is Beta Comae Berenices, a 4.2-[[Apparent magnitude|magnitude]] [[main sequence]] star similar to the Sun. Coma Berenices contains the [[North Galactic Pole]] and one of the richest-known [[galaxy cluster]]s, the [[Coma Cluster]], part of the [[Coma Supercluster]]. Galaxy [[Malin 1]], in the constellation, is the first-known giant [[low-surface-brightness galaxy]]. [[Supernova]] [[SN 1940B]] was the first scientifically observed (underway) [[type II supernova]]. [[FK Comae Berenices]] is the prototype of an [[Variable star#FK Comae Berenices variables|eponymous class of variable stars]]. The constellation is the [[radiant (meteor shower)|radiant]] of one [[meteor shower]], [[Coma Berenicids]], which has one of the fastest meteor speeds, up to {{convert|65|km/s}}.

== History ==
[[Image:Head Berenike II Glyptothek Munich.jpg|thumb|180px|alt=See caption|Bust of [[Berenice II of Egypt]]]]
Coma Berenices has been recognized as an [[asterism (astronomy)|asterism]] since the [[Hellenistic period]]<ref name="pasachoff">{{cite book |title= Stars and Planets |first= Jay M. |last= Pasachoff |year = 2006 |publisher= Houghton Mifflin |location= Boston, Massachusetts}}</ref> (or much earlier, according to some authors), and is the only [[88 modern constellations|modern constellation]] named for an historic figure.{{sfn|Van Oppen de Ruiter|2015|p=109}} It was introduced to Western astronomy during the third century BC by [[Conon of Samos]], the court astronomer of Egyptian ruler [[Ptolemy III Euergetes]], to honour Ptolemy's consort, [[Berenice II of Egypt|Berenice&nbsp;II]].<ref>{{cite book |author= Gaius Julius Hyginus |title= Astronomica |year= 1589 |publisher= [Heidelbergae] In Officina Sanctandreana |url= https://archive.org/details/astronomicaveter00proc |section= 2.24|author-link= Gaius Julius Hyginus }}</ref> Berenice vowed to sacrifice her long hair as a [[votive offering]] if Ptolemy returned safely from battle during the [[Syrian Wars|Third Syrian War]].<ref name="Barentine">{{cite book |first= John C. |last= Barentine |title= Uncharted Constellations: Asterisms, Single-Source and Rebrands |publisher =Springer |year=2016| page=17 |isbn= 978-3-319-27619-9}}</ref> Modern scholars are uncertain if Berenice made the sacrifice before or after Ptolemy's return; it was suggested that it happened after Ptolemy's return (around March–June or May 245 BC), when Conon presented the asterism jointly with scholar and poet [[Callimachus]] during a public evening ceremony.<ref>{{cite book |last= Van Oppen de Ruiter |first= Branko F. |title =Berenice II Euergetis: Essays in Early Hellenistic Queenship |publisher=Springer| year=2015 |page=110 |isbn=978-1-137-49462-7}}</ref> In Callimachus' poem, ''[[Aetia (Callimachus)|Aetia]]'' (composed around that time), Berenice dedicated her tresses "to all the gods". In Poem 66, the Latin translation by the Roman poet [[Catullus]], and in [[Gaius Julius Hyginus|Hyginus]]' ''[[De Astronomica]]'', she dedicated her tresses to [[Aphrodite]] and placed them in the [[Sanctuary of Arsinoe Aphrodite at Cape Zephyrion|temple of Arsinoe II]] (identified after Berenice's death with Aphrodite) at [[Zephyrium]]. According to ''De astronomica'', by the next morning the tresses had disappeared. Conon proposed that Aphrodite had placed the tresses in the sky as an acknowledgement of Berenice's sacrifice.<ref name="Barentine"/> Callimachus called the asterism ''plokamos Berenikēs'' or ''bostrukhon Berenikēs'' in Greek, translated into Latin as "Coma Berenices" by Catullus. [[Hipparchus]]{{r|ley196312}} and [[Geminus]] also recognized it as a distinct constellation.<ref>{{cite book | first=Elly |last= Dekker |author-link=Elly Dekker|title= Illustrating the Phaenomena: Celestial Cartography in Antiquity and the Middle Ages |publisher= Oxford University Press |location= Oxford, United Kingdom |year=2012 |page=41 |isbn=978-0-19-960969-7}}</ref> [[Eratosthenes]] called it "Berenice's Hair" and "[[Ariadne]]'s Hair", considering it part of the constellation [[Leo (constellation)|Leo]].<ref>{{cite book |last= Garfinkle |first=Robert |title= Star-Hopping: Your Visa to Viewing the Universe| publisher=Cambridge University Press |location= Cambridge, United Kingdom |year=1997 |page=122 |isbn =0-521-59889-3}}</ref> Similarly, [[Ptolemy]] did not include it among his 48 constellations in the ''[[Almagest]]'';<ref name="ley196312">{{Cite magazine |last=Ley |first=Willy |date=December 1963 |title=The Names of the Constellations |department=For Your Information |url=https://archive.org/stream/Galaxy_v22n02_1963-12#page/n46/mode/1up |magazine=Galaxy Science Fiction |pages=90–99}}</ref> considering it part of Leo<ref name="pasachoff"/> and calling it ''Plokamos''.<ref name="Kunitzsch">{{cite web |url= http://opar.unior.it/473/1/P._Kunitzsch_pp.19-28_pdf.pdf |title= Albumasariana |work= Annali Istituto Universitario Orientale di Napoli |publisher= OPAR L'Orientale Open Archive |first=Paul |last= Kunitzsch |page=4 |date=2002 |access-date =6 November 2016}}</ref>

[[Image:Virgo et Coma Berenices - Mercator.jpeg|thumb|left|180px|alt=Sixteenth-century sky map superimposed on a globe|Coma Berenices on Mercator's 1551 celestial globe, in the upper left]]
Coma Berenices became popular during the 16th century. In 1515, a set of [[Gore (segment)|gores]] by [[Johannes Schöner]] labelled the asterism ''Trica'', "hair". In 1536 it appeared on a [[celestial globe]] by [[Caspar Vopel]], who is credited with the asterism's designation as a constellation.<ref>{{cite web |url = http://www.ianridpath.com/startales/comaberenices.html |title = Coma Berenices |first = Ian |last = Ridpath |work = Star Tales |access-date = 11 April 2012}}</ref> That year, it also appeared on a celestial map by [[Petrus Apianus]] as "Crines Berenices". In 1551, Coma Berenices appeared on a [[celestial globe]] by [[Gerardus Mercator]] with five Latin and Greek names: Cincinnus, ''caesaries'', ''πλόκαμος'', ''Berenicis crinis'' and Trica. Mercator's reputation as a cartographer ensured the constellation's inclusion on Dutch sky globes beginning in 1589.<ref name="Dekker">{{cite web | url =http://www.atlascoelestis.com/Vopel%202010%20base.htm|title=Caspar Vopel's Ventures in Sixteenth-Century Celestial Cartography|first=Elly |last= Dekker|author-link=Elly Dekker|publisher=Atlas Coelestis| access-date =15 Aug 2016}}</ref>

[[Tycho Brahe]], also credited with Coma's designation as a constellation, included it in his 1602 [[star catalogue]].<ref name="pasachoff"/> Brahe recorded fourteen stars in the constellation; [[Johannes Hevelius]] increased its number to twenty-one, and [[John Flamsteed]] to forty-three. Coma Berenices also appeared in [[Johann Bayer]]'s 1603 ''[[Uranometria]]'', and a few other 17th-century celestial maps followed suit. Coma Berenices and the now-obsolete [[Antinous (constellation)|Antinous]] are considered the first post-Ptolemaic constellations depicted on a celestial globe.<ref>{{cite book | first=John | last=Lankford | year=2011 | title=History of Astronomy: An Encyclopedia | page=[https://archive.org/details/historyofastrono00john/page/165 165] | publisher=Taylor & Francis | isbn=978-0-8153-0322-0 | url-access=registration | url=https://archive.org/details/historyofastrono00john/page/165 }}</ref> With Antinous, Coma Berenices exemplified a trend in astronomy in which globe- and map-makers continued to rely on the ancients for data. This trend ended at the turn of the 16th century with observations of the [[Southern Celestial Hemisphere|southern sky]] and the work of Tycho Brahe.<ref name="Dekker"/>

Before the 18th century Coma Berenices was known in English by several names, including "Berenice's Bush" and "Berenice's [[Wig|periwig]]".<ref name="allen">{{cite web | url =https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Coma_Berenices*.html|title=Star Names Their Lore and Meaning |first=Richard Hinckley |last=Allen|publisher=[[LacusCurtius]]| access-date =19 July 2016}}</ref> The earliest-known English name, "Berenices haire", dates to 1601.<ref name="allen"/><ref>{{cite encyclopedia | url =http://www.etymonline.com/index.php?term=Berenice |title=Berenice|dictionary=[[Online Etymology Dictionary]]| access-date =19 July 2016}}</ref> By 1702 the constellation was known as Coma Berenices,<ref>{{cite book | title =An Introduction to Astronomy, Geography, Navigation and Other Mathematical Sciences, Made Easie by the Description and Uses of the Coelestial and Terrestrial Globes| first1=William |last1=Leybourn |first2= Robert |last2=Morden|publisher =R. Morden| year =1702| page =30}}</ref> and appears as such in the 1731 ''[[An Universal Etymological English Dictionary|Universal Etymological English Dictionary]]''.

===Non-Western astronomy===
Coma Berenices was known to the [[Akkadians]] as Ḫegala.<ref>{{cite book | author1=Douglas B. Miller |author2=R. Mark Shipp| title =An Akkadian Handbook: Paradigms, Helps, Glossary, Logograms, and Sign List| publisher =Eisenbrauns| year =1996| page =53| isbn =0-931464-86-2}}</ref> In [[Babylonian astronomy]] a star, known as ḪÉ.GÁL-''a''-''a'' (translated as "which is before it") or MÚL.ḪÉ.GÁL-''a''-''a'', is tentatively considered part of Coma Berenices.<ref>{{cite web| url =http://www.undena.com/EL-UP/Reiner_and_Pingree_1981_Enuma_Anu_Enlil_-_BM_2.2.pdf| title =Babylonian Planetary Omens. Part Two. Enūma Anu Enlil Tablets 50–51| author1=E. Reiner |author2=D. Pingree| publisher =Undena Publications| date =1985| access-date =10 July 2016| url-status =dead| archive-url =https://web.archive.org/web/20160816205420/http://www.undena.com/EL-UP/Reiner_and_Pingree_1981_Enuma_Anu_Enlil_-_BM_2.2.pdf| archive-date =16 August 2016}}</ref> It was also argued that Coma Berenices appears in Egyptian [[Ramesside star clocks]] as ''sb3w ꜥš3w'', meaning "many stars".<ref>{{cite web | url =http://www.iac.es/proyecto/arqueoastronomia/media/Belmonte_Shaltout_Chapter_6.pdf |title=In Search of Cosmic Order: Selected Essays on Egyptian Archaeoastronomy|author1=José Lull |author2=Juan Antonio Belmonte|page=177|publisher=[[Instituto de Astrofísica de Canarias]]}}</ref>

In [[Astronomy in the medieval Islamic world|Arabic astronomy]] Coma Berenices was known as ''Al-Dafira الضفيرة ("braid"),'' ''Al-Hulba'' ''الهلبة'' and ''Al-Thu'aba الذؤابة'' (both meaning "tuft"), the latter two are translations of the Ptolemaic ''Plokamos'', forming the tuft of the constellation [[Leo (constellation)|Leo]]<ref name="Kunitzsch"/> and including most of the [[Flamsteed designation|Flamsteed-designated]] stars (particularly [[12 Comae Berenices|12]], [[13 Comae Berenices|13]], [[14 Comae Berenices|14]], [[16 Comae Berenices|16]], [[17 Comae Berenices|17]], [[18 Comae Berenices|18]] and [[21 Comae Berenices]]).<ref>{{cite web | url =http://onesky.arizona.edu/arab-star-names/the-tail-hair/ |title=The Tail Hair |publisher=Two Deserts One Sky| access-date =6 November 2016}}</ref> [[Abd al-Rahman al-Sufi|Al-Sufi]] included it in Leo. [[Ulugh Beg]], however, regarded ''Al-Dafira'' as consisting of two stars, [[7 Comae Berenices|7]] and [[23 Comae Berenices]].<ref>{{cite book | author=Royal Astronomical Society|volume=14–15| title =Memoirs of the Royal Astronomical Society| year =1843| page =191}}</ref> R. H. Allen's ''[[Star Names]]'' gives the name ''Al Ḍafīrah'' to 15 = [[Gamma Comae Berenices]].<ref name="allen"/>

The North American [[Pawnee people]] depicted Coma Berenices as ten faint stars on a [[Tanning (leather)|tanned]] elk-skin star map dated to at least the 17th century.<ref>{{cite magazine | author=Ralph N. Buckstaff | title =Stars and Constellations of a Pawnee Sky Map | magazine =[[American Anthropologist]]| year =1927| volume=29|issue=2|page =282}}</ref> In the South American [[Kalina people|Kalina]] mythology, the constellation was known as ''ombatapo'' (face).<ref name="Mythologiques">{{cite book | first=Claude |last=Lévi-Strauss| title =Mythologiques| publisher =University of Chicago Press| year =1983| page =232| isbn =0-226-47487-9}}</ref>

The constellation was also recognized by several [[Polynesian peoples]]. The people of [[Tonga]] had four names for Coma Berenices: ''Fatana-lua'', ''Fata-olunga'', ''Fata-lalo'' and ''Kapakau-o-Tafahi''.<ref>{{cite book | author = Maud Worcester Makemson | year = 1941 | publisher = Yale University Press | title = The Morning Star Rises: an account of Polynesian astronomy| page=281| bibcode = 1941msra.book.....M }}</ref> The [[Boorong people]] called the constellation ''Tourt-chinboiong-gherra'', and saw it as a small flock of birds drinking rainwater from a puddle in the [[wikt:crotch|crotch]] of a tree.<ref>{{cite book | editor=Helaine Selin| title =Astronomy Across Cultures: The History of Non-Western Astronomy| publisher =Springer Science & Business Media| year =2012| page =75| isbn =978-94-011-4179-6}}</ref> The people of the [[Pukapuka]] atoll may have called it ''Te Yiku-o-te-kiole'', although sometimes this name is associated with [[Ursa Major]].<ref>{{cite book | author=Slovenská akadémia vied. Kabinet orientalistiky| title =Asian and African Studies| publisher =Veda| year =1999| page =32| volume =8}}</ref>

==Characteristics==
Coma Berenices is bordered by Boötes to the east, Canes Venatici to the north, Leo to the west and Virgo to the south. Covering 386.5&nbsp;square degrees and 0.937% of the night sky, it ranks 42nd of the [[IAU designated constellations by area|88 constellations by area]].<ref name=tirionconst/> The three-letter abbreviation for the constellation, as adopted by the [[International Astronomical Union]] in 1922, is "Com".<ref name="pa30_469">{{cite journal|last=Russell|first=Henry Norris|author-link=Henry Norris Russell|title=The New International Symbols for the Constellations|journal=[[Popular Astronomy (US magazine)|Popular Astronomy]]|volume=30|page=469 |bibcode=1922PA.....30..469R|date=1922}}</ref> The official constellation boundaries, as set by Belgian astronomer [[Eugène Joseph Delporte|Eugène Delporte]] in 1930,{{efn|1=Delporte had proposed standardising the constellation boundaries to the International Astronomical Union, who had agreed and gave him the lead role<ref name=tirionconstbnd>{{cite web|url=http://www.ianridpath.com/boundaries.html|title=Constellation boundaries: How the modern constellation outlines came to be|work=Star Tales|author=Ridpath, Ian|author-link=Ian Ridpath|publisher=self-published |access-date= 1 June 2016}}</ref>}} are defined by a polygon of 12 segments (''illustrated in infobox''). In the [[equatorial coordinate system]], the [[right ascension]] coordinates of these borders lie between {{RA|11|58|25.09}} and {{RA|13|36|06.94}}, and the [[declination]] coordinates are between +13.30° and +33.31°.<ref name="boundary"/> Coma Berenices is wholly visible to observers north of latitude [[56th parallel south|56°S]].{{efn|1=While parts of the constellation technically rise above the horizon to observers between 56°S and [[77th parallel south|77°S]], stars within a few degrees of the horizon are to all intents and purposes unobservable.<ref name=tirionconst/>}} and the constellation's midnight [[culmination]] occurs on 2 April.<ref>{{cite book | author1=Robert Thompson |author2=Barbara Thompson| title =Illustrated Guide to Astronomical Wonders: From Novice to Master Observer| publisher =O'Reilly Media, Inc.| year =2007| page =184| isbn =978-0-596-52685-6}}</ref>

== Features ==
[[Image:Coma Berenices photograph.jpg|thumb|250px|alt=Black-on-white photo of the constellation|Coma Berenices' major stars]]
Although it is not large, Coma Berenices contains one galactic [[supercluster]], two [[Open cluster|galactic clusters]], one [[star cluster]] and eight [[Messier object]]s (including several [[globular cluster]]s). These objects can be seen with minimal obscuration by dust because the constellation is not in the direction of the [[galactic plane]]. Because of that, there are few [[open cluster]]s (except for the Coma Berenices Cluster, which dominates the northern part of the constellation), diffuse [[nebula]]e or [[planetary nebula]]e. Coma Berenices contains the [[Galactic coordinate system|North Galactic Pole]] at [[right ascension]] {{RA|12|51|25}} and [[declination]] {{DEC|+27|07|48}} (epoch [[J2000.0]]).

=== Stars ===
{{further|List of stars in Coma Berenices}}

==== Brightest stars ====
[[Image:ComaBerenicesCC.jpg|thumb|left|alt=Photo of Coma Berenices' three visible stars, which form a triangle|Coma Berenices as seen by the naked eye]]
Coma Berenices is not particularly bright, as none of its stars are brighter than fourth [[apparent magnitude|magnitude]],<ref>{{cite web | url =http://www.prao.ru/Constellations/mif/vol_veroniki.html|title=Волосы Вероники|publisher=Pushchino Radioastronomic Observatory| language=ru| access-date =20 July 2016}}</ref> although there are 66 stars brighter than or equal to [[apparent magnitude]]&nbsp;6.5.{{efn|1=Objects of magnitude 6.5 are among the faintest visible to the unaided eye in suburban–rural transition night skies.<ref>{{cite web|url=http://www.skyandtelescope.com/resources/darksky/3304011.html?page=1&c=y|archive-url=https://archive.today/20121216144730/http://www.skyandtelescope.com/resources/darksky/3304011.html?page=1&c=y|url-status=dead|archive-date=2012-12-16|title=The Bortle Dark-Sky Scale|last=Bortle|first=John E.|date=February 2001|work=[[Sky & Telescope]]|access-date=28 August 2017}}</ref>}}<ref name=tirionconst>{{cite web| url=http://www.ianridpath.com/constellations1.html | title=Constellations: Andromeda–Indus | work= Star Tales |author=Ridpath, Ian |author-link=Ian Ridpath|publisher=self-published | access-date= 26 August 2015}}</ref>

The constellation's brightest star is [[Beta Comae Berenices]] (43 Comae Berenices in [[Flamsteed designation]]), at magnitude 4.2 and with a high [[proper motion]]. In Coma Berenices' northeastern region, it is 29.95 ± 0.10 [[light-year]]s from Earth.<ref name=Gaia-DR2beta>{{cite DR2|1460229369573307264}}</ref> A [[solar analog]], it is a yellow-hued [[F-type main-sequence star]] with a [[spectral class]] of F9.5V B.<ref>{{cite simbad | title =bet Com | access-date =19 November 2016}}</ref> Beta Comae Berenices is around 36% brighter,<ref name=apj746_1_101>{{cite journal | last1=Boyajian | first1=Tabetha S. | last2=McAlister | first2=Harold A. | last3=van Belle | first3=Gerard | last4=Gies | first4=Douglas R. | last5=ten Brummelaar | first5=Theo A. | last6=von Braun | first6=Kaspar | last7=Farrington | first7=Chris | last8=Goldfinger | first8=P. J. | last9=O'Brien | first9=David | last10=Parks | first10=J. Robert | last11=Richardson | first11=Noel D. | last12=Ridgway | first12=Stephen | last13=Schaefer | first13=Gail | last14=Sturmann | first14=Laszlo | last15=Sturmann | first15=Judit | last16=Touhami | first16=Yamina | last17=Turner | first17=Nils H. | last18=White | first18=Russel | title=Stellar Diameters and Temperatures. I. Main-sequence A, F, and G Stars | journal=The Astrophysical Journal | volume=746 | issue=1 | page=101 |date=2012 | doi=10.1088/0004-637X/746/1/101 | bibcode=2012ApJ...746..101B | arxiv=1112.3316 | s2cid=18993744 }}. See Table 10.</ref> and 15% more massive than the [[Sun]],<ref name=apjss168>{{cite journal | last1=Takeda | first1=G. | last2=Ford | first2=E. B. | last3=Sills | first3=A. | last4=Rasio | first4=F. A. | last5=Fischer | first5=D. A. | last6=Valenti | first6=J. A. | title=Stellar parameters of nearby cool stars. II. Physical properties of ~1000 cool stars from the SPOCS catalog | journal=Astrophysical Journal Supplement Series | volume=168 | issue=2 | pages=297–318 | year=2007 | bibcode=2007ApJS..168..297T | doi=10.1086/509763|arxiv = astro-ph/0607235 | s2cid=18775378 }} ''Note:'' see VizieR catalogue [http://cdsarc.u-strasbg.fr/viz-bin/Cat?J/ApJS/168/297 J/ApJS/168/297].</ref> and with a radius 10% larger.<ref name=apj746_1_101/>

The second-brightest star in Coma Berenices is the 4.3-magnitude, bluish [[Alpha Comae Berenices]] (42 Comae Berenices), with the [[Proper names (astronomy)|proper name]] Diadem,<ref name="IAU-LSN">{{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars |publisher=IAU.org |access-date=16 July 2022}}</ref> in the southeastern part of the constellation. Despite its Alpha [[Bayer designation]], the star is dimmer than Beta Comae Berenices, being one of the cases where designation does not correspond to the brightest star. It is a [[double star]], with the spectral classes of F5V and F6V.<ref>{{cite simbad |title=alf Com | access-date =22 November 2016}}</ref> <!-- To be reffed Because its [[orbital plane (astronomy)|orbital plane]] is near the Earth's line of sight, it was long suspected of being an eclipsing [[binary star]]. It now appears that Alpha Comae Berenices's orbital tilt is 0.1° relative to the line of sight, so the stars do not eclipse each other when seen from Earth.--> The star system is 58.1 ± 0.9 light-years from Earth.<ref name="vanLeeuwen2007">{{cite journal | first=F. | last=van Leeuwen | title=Validation of the New Hipparcos Reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–64 | date=2007 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | arxiv=0708.1752| s2cid=18759600 }}</ref>

[[Gamma Comae Berenices]] (15 Comae Berenices) is an orange-hued [[giant star]] with a magnitude of 4.4 and a spectral class of K1III C. In the southwestern part of the constellation, it is 169 ± 2 light-years from Earth,<ref name=Gaia-DR2gamma>{{cite DR2|4009317512294635008}}</ref> Estimated to be around 1.79 times as massive as the Sun,<ref name=Luck>{{cite journal|bibcode=2015AJ....150...88L|doi=10.1088/0004-6256/150/3/88|arxiv=1507.01466|title=Abundances in the Local Region. I. G and K Giants|journal=The Astronomical Journal|volume=150|issue=3|pages=88|year=2015|last1=Luck|first1=R. Earle|s2cid=118505114}}</ref> it has expanded to around 10 times its radius.<ref name=cadars2>{{cite journal
 | display-authors=1 | last1=Pasinetti Fracassini | first1=L. E.
 | last2=Pastori | first2=L. | last3=Covino | first3=S. | last4=Pozzi | first4=A.
 | title=Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)
 | edition=Third | journal=Astronomy & Astrophysics
 | volume=367 | issue=2 | pages=521–24 | date=2001
 | bibcode=2001A&A...367..521P | arxiv=astro-ph/0012289
 | doi=10.1051/0004-6361:20000451 | s2cid=425754 }} [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=II/224/cadars.dat&recno=5636 HD 108381] Accessed on line October 12, 2010.</ref> It is the brightest star in the [[Coma Star Cluster]].<ref>{{cite web | url =http://www.jdso.org/volume10/number1/Schlimmer_25_28.pdf|title=Discovery of Small Companions of Comae and TYC 1989-00307-1 in Constellation Coma Berenices and a Possible New Common Proper Motion Pair in the Constellation Canes Venatici |author=Joerg S. Schlimmer |work=Journal of Double Star Observations | date=January 1, 2014| access-date =25 November 2016}}</ref> With Alpha Comae Berenices and Beta Comae Berenices, Gamma Comae Berenices forms a 45-degree [[isosceles triangle]] from which Berenice's imaginary tresses hang.

==== Star systems ====
The [[star system]]s of Coma Berenices include [[binary star|binary]], [[double star|double]] and triple stars. [[21 Comae Berenices]] (sometimes called Kissin, but this name is shared with [[23 Comae Berenices]]) is a [[Double star|close binary]] with nearly equal components and an [[orbital period]] of 26 years.<ref name="Moore">{{cite book | author1=Patrick Moore |author2=Robin Rees| title =Patrick Moore's Data Book of Astronomy| publisher =Cambridge University Press| year =2014| page =412| isbn =978-1-139-49522-6}}</ref> The system is 272 ± 3 light-years away.<ref name=Gaia-DR221>{{cite DR2|3959965486205062528}}</ref> The [[Coma Cluster]] contains at least eight [[spectroscopic binary|spectroscopic binaries]],<ref name="Burnham">{{cite book|last=Burnham|first=Robert|title=Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System, v.2|page=672|publisher=Courier Corporation|year=2013|isbn=978-0-486-31793-9}}</ref> and the constellation has seven [[eclipsing binary|eclipsing binaries]]: [[CC Comae Berenices|CC]], [[DD Comae Berenices|DD]], [[EK Comae Berenices|EK]], [[RW Comae Berenices|RW]], [[RZ Comae Berenices|RZ]], [[SS Comae Berenices|SS]] and [[UX Comae Berenices]].<ref>{{cite web | url =http://www.as.up.krakow.pl/o-c/cont.html#com |title=Atlas of O-C Diagrams of Eclipsing Binary Stars|publisher=Mt. Suhora Astronomical Observatory| access-date =6 November 2016}}</ref>

There are over thirty [[double star]]s in Coma Berenices,<ref>{{cite web|url=http://www.eaglecreekobservatory.org/eco/doubles/com.html|title=Double Stars in Coma Berenices|publisher=[[Eagle Creek Observatory]]|access-date=6 November 2016|archive-url=https://web.archive.org/web/20161125044444/http://www.eaglecreekobservatory.org/eco/doubles/com.html|archive-date=25 November 2016|url-status=dead}}</ref> including [[24 Comae Berenices]] with contrasting colors. Its primary is an orange-hued giant star with a magnitude of 5.0, 610 light-years from Earth, and its secondary is a blue-white-hued star with a magnitude of 6.6. Triple stars include [[12 Comae Berenices]], [[17 Comae Berenices]], [[KR Comae Berenices]] and [[Struve 1639]].{{sfn|Garfinkle|1997|pp=127–128}}<ref>{{cite journal | url =http://www.aanda.org/articles/aa/abs/2010/11/aa14888-10/aa14888-10.html|title=The triple system KR Comae Berenices|journal=[[Astronomy & Astrophysics]]|author1=P. Zasche |author2=R. Uhlář| date=15 September 2010|volume=519 |pages=A78 |doi=10.1051/0004-6361/201014888 |arxiv=1011.6563 |bibcode=2010A&A...519A..78Z |s2cid=118435158 | access-date =24 November 2016}}</ref>

==== Variable stars ====
Over 200 [[variable star]]s are known in Coma Berenices, although many are obscure.<ref name="ut"/> [[Alpha Comae Berenices]] is a possible [[Algol variable]].<ref>{{cite web | url =https://www.aavso.org/aavso-alert-notice-506|title=Alert Notice 506: Alpha Com eclipse observing campaign|publisher=[[AAVSO]]| date=January 16, 2015| access-date =24 November 2016}}</ref> [[FK Comae Berenices]], which varies from magnitude 8.14 to 8.33 over a period of 2.4 days, is the prototype for the [[FK Comae Berenices variable|FK Comae Berenices class]] of variable stars<ref name="ut"/> and the star in which the "[[Starspot|flip-flop phenomenon]]" was discovered.<ref>{{Cite journal| arxiv =1211.0914|title=Flip-flops of FK Comae Berenices|journal=Astronomy & Astrophysics|volume=553|pages=A40|author1=Thomas Hackman |author2=Jaan Pelt |author3=Maarit J. Mantere |author4=Lauri Jetsu |author5=Heidi Korhonen |author6=Thomas Granzer |author7=Perttu Kajatkari |author8=Jyri Lehtinen |author9=Klaus G. Strassmeier| date=22 March 2013|doi=10.1051/0004-6361/201220690|bibcode=2013A&A...553A..40H|s2cid=118705220}}</ref> [[FS Comae Berenices]] is a [[Semiregular variable star|semi-regular variable]], a [[red giant]] with a period of about two months whose magnitude varies between 6.1 and 5.3. [[R Comae Berenices]] is a [[Mira variable]] with a maximum magnitude of almost 7.<ref>{{cite book | author1=H.J.P Arnold |author2=Paul Doherty |author3=Patrick Moore| title =The Photographic Atlas of the Stars| publisher =CRC Press| year =1999| page =128| isbn =0-7503-0654-8}}</ref> There are 123 [[RR Lyrae variable]]s in the constellation,<ref>{{cite web | url =http://www.ast.obs-mip.fr/users/leborgne/dbRR/|title=Coma Berenices|publisher=RR Lyrae stars: the GEOS maxima database | date=11 March 2008| access-date =22 November 2016}}</ref> with many in the [[Messier 53|M53]] cluster.<ref name="m53"/> One of these stars, [[TU Comae Berenices]], may have a [[binary system]].<ref>{{cite journal | arxiv =1605.03242 |title=TU Comae Berenices : Blazhko RR Lyrae Star in a Potential Binary System|author1=Pierre de Ponthiere |author2=Franz-Josef Hambsch |author3=Kenneth Menzies |author4=Richard Sabo|journal=Journal of the American Association of Variable Star Observers (Jaavso)| date=10 May 2016|volume=44|issue=1|page=18|bibcode=2016JAVSO..44...18D}}</ref> The [[Messier 100|M100]] galaxy contains about twenty [[Cepheid variable]]s, which were observed by the [[Hubble Space Telescope]].<ref name="m100"/> Coma Berenices also contains [[Alpha2 Canum Venaticorum variable|Alpha<sup>2</sup> Canum Venaticorum variables]], such as [[13 Comae Berenices]] and [[AI Comae Berenices]].{{sfn|Garfinkle|1997|p=127}}

In 2019 scientists at [[Aryabhatta Research Institute of Observational Sciences]] announced the discovery of 28 new variable stars in Coma Berenices' globular cluster [[NGC 4147]].<ref>{{cite web | url =https://www.hindustantimes.com/india-news/indian-scientists-discover-28-new-milky-way-stars/story-v4rkpqzGA7jfUeD6iKbJcK.html |title=Indian scientists discover 28 new Milky Way stars|newspaper=[[Hindustan Times]]| date=27 July 2019| access-date =10 November 2019}}</ref>

==== Supernovae ====
A number of [[supernova]]e have been discovered in Coma Berenices. Four ([[SN 1940B]], [[SN 1969H]], [[SN 1987E]] and [[SN 1999gs]]) were in the [[NGC 4725]] galaxy,<ref name="iau">{{cite web | url =http://www.cbat.eps.harvard.edu/lists/Supernovae.html |title=List of Supernovae|publisher=IAU Central Bureau for Astronomical Telegrams| access-date =6 November 2016}}</ref> and another four were discovered in the [[Messier 99|M99]] galaxy (NGC 4254): [[SN 1967H]], [[SN 1972Q]], [[SN 1986I]] and [[SN 2014L]].<ref name="iau"/> Five were discovered in the [[Messier 100|M100]] galaxy (NGC 4321): [[SN 1901B]], [[SN 1914A]], [[SN 1959E]], [[SN 1979C]] and [[SN 2006X]].<ref name="iau"/> SN 1940B, discovered on 5 May 1940, was the first observed [[type II supernova]].<ref>{{cite book | editor=Albert G. Petschek| title =Supernovae| publisher =Springer Science & Business Media| year =2012| page =60| isbn =978-1-4612-3286-5}}</ref> [[SN 2005ap]], discovered on 3 March 2005, is the second-brightest-known supernova to date with a peak [[absolute magnitude]] of about −22.7.<ref>{{Cite journal|title=SN 2005ap: A Most Brilliant Explosion|journal=The Astrophysical Journal|volume=668|issue=2|pages=L99–L102|author1=Robert M. Quimby |author2=Greg Aldering |author3=J. Craig Wheeler |author4=Peter Höflich |author5=Carl W. Akerlof |author6=Eli S. Rykoff| date=3 September 2007|doi= 10.1086/522862|arxiv = 0709.0302 |bibcode = 2007ApJ...668L..99Q |s2cid=18897235}}</ref> Due to its great distance from Earth (4.7 billion light-years), it was not visible to the naked eye and was discovered telescopically. SN&nbsp;1979C, discovered in 1979, retained its original [[X-ray]] brightness for 25 years despite fading in visible light.<ref>{{cite web | url =http://www.esa.int/Our_Activities/Space_Science/The_supernova_that_just_won_t_fade_away|title=The supernova that just won't fade away|publisher=[[ESA]]| date=21 July 2005| access-date =25 November 2016}}</ref>

==== Other stars ====
Coma Berenices also contains the [[neutron star]] [[RBS 1223]] and the [[pulsar]] [[PSR B1237+25]].<ref name="Nagle"/> RBS 1223 is a member of [[The Magnificent Seven (neutron stars)|the Magnificent Seven]], a group of young neutron stars.<ref>{{Cite journal|title=The Magnificent Seven: Magnetic fields and surface temperature distributions|journal=Astrophysics and Space Science|volume=308|issue=1–4|pages=181–190|author=F. Haberl|doi=10.1007/s10509-007-9342-x| date=4 September 2006|arxiv = astro-ph/0609066 |bibcode = 2007Ap&SS.308..181H |s2cid=15013359}}</ref> In 1975, the first extra-solar source of [[extreme ultraviolet]], the white dwarf [[HZ 43]], was discovered in Coma Berenices.<ref>{{cite journal | journal=[[New Scientist]]|title=Two satellites to observe the unobservable| issue =1684| date =30 September 1989| page =56| issn =0262-4079}}</ref> In 1995, there was a very rare outburst of the WZ Sagittae-type [[dwarf nova]] [[AL Comae Berenices]].<ref>{{cite book | last= Mobberley|first=Martin| title =Cataclysmic Cosmic Events and How to Observe Them| url= https://archive.org/details/cataclysmiccosmi00mobb| url-access= registration| publisher =Springer Science & Business Media| year =2009| page =[https://archive.org/details/cataclysmiccosmi00mobb/page/n54 32]| isbn =978-0-387-79946-9}}</ref> A June 2003 outburst from [[GO Comae Berenices]], an SU Ursae Majoris-type dwarf nova, was [[Photometry (astronomy)|photometrically]] observed.<ref>{{cite journal | arxiv =astro-ph/0412450 |title=The 2003 Superoutburst of an SU UMa-type Dwarf Nova, GO Comae Berenices|author1=Akira Imada |author2=Taichi Kato |author3=Makoto Uemura |author4=Ryoko Ishioka |author5=Thomas Krajci |author6=Yasuo Sano |author7=Tonny Vanmunster |author8=Donn R.Starkey |author9=Lewis M.Cook |author10=Jochen Pietz |author11=Daisaku Nogami |author12=Bill Yeung |author13=Kazuhiro Nakajima |author14=Kenji Tanabe |author15=Mitsuo Koizumi |author16=Hiroki Taguchi |author17=Norimi Yamada |author18=Yuichi Nishi |author19=Brian Martin |author20=Ken'ichi Torii |author21=Kenzo Kinugasa |author22=Christopher P.Jones|journal=Revista Mexicana de Astronomía y Astrofísica, Serie de Conferencias| date=17 December 2004|volume=20|page=265|bibcode=2004RMxAC..20..265I}}</ref>

=== Exoplanets ===
Coma Berenices has seven known [[exoplanet]]s.<ref>{{cite web| url =http://phl.upr.edu/projects/habitable-exoplanets-catalog/stats/constellations| title =HEC: The Constellations of Exoplanets| publisher =Planetary Habitability Laboratory University of Puerto Rico at Arecibo| access-date =24 November 2016| archive-date =15 August 2016| archive-url =https://web.archive.org/web/20160815091731/http://phl.upr.edu/projects/habitable-exoplanets-catalog/stats/constellations| url-status =dead}}</ref> One, [[HD 108874 b]], has Earth-like [[insolation]].<ref>{{cite book | title=Naming the extrasolar planets|author=W. Lyra |publisher=INSPIRE / High-Energy Physics |page=23}}</ref> [[WASP-56]] is a sun-like star of spectral type G6 and apparent magnitude 11.48 with a planet 0.6 the mass of [[Jupiter]] that has a period of 4.6 days.<ref>{{cite journal|display-authors=8|author=Faedi, F.|author2=Pollacco, D.|author3=Barros, S. C. C.|author4=Brown, D.|author5=Collier Cameron, A.|author6=Doyle, A. P.|author7= Enoch, R.|author8=Gillon, M.|author9=Gómez Maqueo Chew, Y.|author10=Hébrard, G.|author11=Lendl, M.|author12=Liebig, C.|author13=Smalley, B.|author14=Triaud, A. H. M. J.|author15=West, R. G.|author16=Wheatley, P. J.|author17=Alsubai, K. A.|author18=Anderson, D. R.|author19=Armstrong, D.|author20=Bento, J.|author21=Bochinski, J.|author22=Bouchy, F.|author23=Busuttil, R.|author24=Fossati, L.|author25=Fumel, A.|author26=Haswell, C. A.|author27=Hellier, C.|author28=Holmes, S.|author29=Jehin, E.|author30=Kolb, U.|author31=McCormac, J. |author32= Miller, G. R. M. |author33= Moutou, C. |author34= Norton, A. J.|author35= Parley, N.|author36= Queloz, D.|author37= Santerne, A.|author38= Skillen, I.|author39= Smith, A. M. S.|author40= Udry, S.|author41=  Watson, C. |date=2013|title=WASP-54b, WASP-56b, and WASP-57b: Three New Sub-Jupiter Mass Planets from SuperWASP|journal=Astronomy and Astrophysics|volume=551|pages=A73–90|doi=10.1051/0004-6361/201220520|arxiv = 1210.2329 |bibcode = 2013A&A...551A..73F |s2cid=14346225}}</ref>

=== Star clusters ===

==== Coma Star Cluster ====
The [[Coma Star Cluster]] represents Berenice's sacrificed tresses and as a naked eye object has been known since antiquity, appearing in Ptolemy's ''[[Almagest]]''.<ref>{{cite web | url =https://britastro.org/node/6424|title=A binocular star cluster for spring skies|publisher=[[British Astronomical Association]]| author=Stewart Moore| access-date =8 September 2017}}</ref> It doesn't have a Messier or NGC designation, but is in the [[Melotte catalogue]] of open clusters (designated Melotte 111) and is also catalogued as Collinder 256. It is a large, diffuse [[open cluster]] of about 50 stars ranging between magnitudes five and ten, including several of Coma Berenices' stars which are visible to the naked eye. The cluster is spread over a huge region (more than five degrees across) near [[Gamma Comae Berenices]]. It has such a large apparent size because it is relatively close, only 280 light-years or 86 parsecs away.<ref name=vanleeuwen09>{{cite journal |title=Parallaxes and proper motions for 20 open clusters as based on the new Hipparcos catalogue |journal=Astronomy and Astrophysics |first=F. |last=van Leeuwen |volume=497 |issue=1 |pages=209–242 |date=April 2009 |bibcode=2009A&A...497..209V |doi=10.1051/0004-6361/200811382|arxiv = 0902.1039 |s2cid=16420237 }}</ref><ref name=majaess11>{{cite journal |title=Deep Infrared ZAMS Fits to Benchmark Open Clusters Hosting Delta Scuti Stars |journal=Journal of the American Association of Variable Star Observers |first1=D. |last1=Majaess |first2=D. |last2=Turner |first3=D. |last3=Lane |first4=T. |last4=Krajci |volume=39 |issue=2 |page=219 |date=September 2011 |bibcode=2011JAVSO..39..219M |arxiv=1102.1705}}</ref>

==== Globular clusters ====
[[Messier 53|M53]] (NGC 5024) is a [[globular cluster]] which was discovered independently by [[Johann Elert Bode]] in 1775 and [[Charles Messier]] in February 1777; [[William Herschel]] was the first to resolve it into stars.<ref name="m53">{{cite web | url =http://messier.seds.org/m/m053.html|title=Messier 53 |publisher=The Messier Catalog| access-date =24 November 2016}}</ref> The magnitude-7.7 cluster is 56,000 light-years from Earth. Only 1° away is [[NGC 5053]], a globular cluster with a sparser nucleus of stars. Its total luminosity is the equivalent of about 16,000 suns, one of the lowest luminosities of any globular cluster. It was discovered by William Herschel in 1784. [[NGC 4147]] is a somewhat dimmer globular cluster, with a much-smaller [[Angular diameter|apparent size]] and an apparent magnitude of 10.7.<ref name=aj144_5_126>{{citation
 | display-authors=1
 | last1=Dalessandro | first1=Emanuele
 | last2=Schiavon | first2=Ricardo P.
 | last3=Rood | first3=Robert T.
 | last4=Ferraro | first4=Francesco R.
 | last5=Sohn | first5=Sangmo T.
 | last6=Lanzoni | first6=Barbara
 | last7=O'Connell | first7=Robert W. 
 | title=Ultraviolet Properties of Galactic Globular Clusters with Galex. II. Integrated Colors 
 | journal=The Astronomical Journal
 | volume=144 | issue=5 | id=126 | pages=13 | date=November 2012
 | doi=10.1088/0004-6256/144/5/126 
 | bibcode=2012AJ....144..126D | arxiv=1208.5698
 | s2cid=56419886 | postscript=.
}}</ref>

=== Galaxies ===

====Coma Supercluster====
The [[Coma Supercluster]], itself part of the [[Coma Filament]], contains the [[Coma Cluster|Coma]] and [[Leo Cluster]] of galaxies. The Coma Cluster ([[Abell catalogue|Abell]] 1656) is 230 to 300 million light-years away. It is one of the largest-known clusters, with at least 10,000 galaxies (mainly [[elliptical galaxy|elliptical]], with a few [[spiral galaxies]]).<ref name="earthsky">{{cite web | url =http://earthsky.org/clusters-nebulae-galaxies/the-coma-berenices-galaxy-cluster|title=Coma Cluster of galaxies|publisher=EarthSky| author=Larry Sessions|date=April 6, 2016| access-date =6 November 2016}}</ref> Due to its distance from Earth, most of the galaxies are visible only through large telescopes. Its brightest members are [[NGC 4874]] and [[NGC 4889]], both with a magnitude of 13; most others are magnitude 15 or dimmer. NGC 4889 is a giant elliptical galaxy with one of the largest-known [[black hole]]s (21 billion [[solar mass]]es),<ref>{{cite journal|title=Two ten-billion-solar-mass black holes at the centres of giant elliptical galaxies |author=Nicholas J. McConnell |date=2011-12-08 |journal=Nature |volume=480|issue=7376 |doi=10.1038/nature10636 |pages=215–218|arxiv = 1112.1078 |bibcode = 2011Natur.480..215M |pmid=22158244 |s2cid=4408896 }}</ref> and [[NGC 4921]] is the cluster's brightest spiral galaxy.<ref>{{cite journal
 | author= S. van den Bergh
 | title=A new classification system for galaxies
 | journal=Astrophysical Journal | volume=206
 | date=1976-06-15 | pages=883–887
 | doi=10.1086/154452
| bibcode=1976ApJ...206..883V| doi-access=free}}</ref> After observing the Coma Cluster, astronomer [[Fritz Zwicky]] first postulated the existence of [[dark matter]] during the 1930s.<ref name="earthsky"/> The massive galaxy [[Dragonfly 44]] discovered in 2015 was found to consist almost entirely of dark matter.<ref name="keck">{{cite web| url =http://www.keckobservatory.org/recent/entry/scientists_discover_massive_galaxy_made_of_99.99_percent_dark_matter| title =Scientists Discover Massive Galaxy Made of 99.99 Percent Dark Matter| publisher =[[Keck Observatory]]| date =25 August 2016| access-date =11 December 2016| archive-url =https://web.archive.org/web/20180525213725/http://www.keckobservatory.org/recent/entry/scientists_discover_massive_galaxy_made_of_99.99_percent_dark_matter| archive-date =25 May 2018| url-status =dead}}</ref> Its mass is very similar to that of the [[Milky Way]],<ref name="keck"/> but it emits only 1% of the light emitted by the Milky Way.<ref>{{cite journal|last1=Crosswell|first1=Ken|title=The Milky Way's dark twin revealed|url=http://www.nature.com/news/the-milky-way-s-dark-twin-revealed-1.20333|access-date=30 July 2016|journal=Nature News|date=26 July 2016|doi=10.1038/nature.2016.20333|s2cid=124730115|url-access=subscription}}</ref> NGC 4676, sometimes called the [[Mice Galaxies]], is a pair of [[interacting galaxy|interacting galaxies]] 300 million light-years from Earth. Its progenitor galaxies were [[spiral galaxy|spiral]], and astronomers estimate that they had their closest approach about 160 million years ago. That approach triggered large regions of [[star formation]] in both galaxies, with long "tails" of dust, stars and gas. The two progenitor galaxies are predicted to interact significantly at least one more time before they merge into a larger, probably-[[elliptical galaxy|elliptical]] galaxy.<ref name="objects">{{cite book |title = 300 Astronomical Objects: A Visual Reference to the Universe |first1 = Jamie |last1 = Wilkins |first2 = Robert |last2 = Dunn |publisher = Firefly Books |year = 2006 |location = Buffalo, New York |isbn = 978-1-55407-175-3}}</ref>

==== Virgo Cluster ====
[[File:25 years of stunning definition Messier 100.jpg|thumb|[[Messier 100]] taken with Hubble's Wide Field Camera 3<ref>{{cite web |title=25 years of stunning definition |url=https://www.spacetelescope.org/images/potw1850a/ |website=www.spacetelescope.org |access-date=10 December 2018 |language=en}}</ref>]]
Coma Berenices contains the northern portion of the [[Virgo Cluster]] (also known as the Coma–Virgo Cluster), about 60 million light-years away. The portion includes six Messier galaxies. [[Messier 85|M85]] (NGC 4382), considered [[elliptical galaxy|elliptical]] or [[lenticular galaxy|lenticular]], is one of the cluster's brighter members at magnitude nine. M85 is interacting with the spiral galaxy [[NGC 4394]] and the elliptical galaxy [[MCG-3-32-38]].<ref name="Nagle">{{cite web | url =http://www.brastro.org/newsletter/2016-June_Newsletter.pdf |title=Coma Berenices|work=Newsletter of the Baton Rouge Astronomical Society| first=John |last= Nagle|date=June 2016| access-date =15 Aug 2016}}</ref> However, it is relatively isolated from the rest of the cluster.<ref name=Escudero>{{cite journal|doi=10.1093/mnras/stac021|bibcode=2022MNRAS.511..393E|arxiv=2201.01759|title=The complex globular cluster system of the S0 galaxy NGC 4382 in the outskirts of the Virgo Cluster|year=2022|last1=Escudero|first1=Carlos G.|last2=Cortesi|first2=Arianna|last3=Faifer|first3=Favio R.|last4=Sesto|first4=Leandro A.|last5=Smith Castelli|first5=Analía V.|last6=Johnston|first6=Evelyn J.|last7=Reynaldi|first7=Victoria|last8=Chies-Santos|first8=Ana L.|last9=Salinas|first9=Ricardo|last10=Menéndez-Delmestre|first10=Karín|last11=Gonçalves|first11=Thiago S.|last12=Grossi|first12=Marco|last13=Mendes De Oliveira|first13=Claudia|journal=Monthly Notices of the Royal Astronomical Society|volume=511|issue=1 |pages=393–412|doi-access=free }}</ref> [[Messier 88|M88]] (NGC 4501) is a multi-arm spiral galaxy seen at about 30° from edge-on. It has a highly-regular shape with well-developed, symmetrical arms. Among the first galaxies recognized as spiral,<ref>{{cite web | url =http://messier.seds.org/m/m088.html|title=Messier 88 |publisher=The Messier Catalog| access-date =20 November 2016}}</ref> it has a [[supermassive black hole]] in its center.<ref name="Nagle"/> [[Messier 91|M91]] (NGC 4548), a [[barred spiral galaxy]] with a bright, diffuse nucleus, is the faintest object in Messier's catalog at magnitude 10.2.<ref>{{cite web | url =http://messier.seds.org/m/m091.html|title=Messier 91 |publisher=The Messier Catalog| access-date =20 November 2016}}</ref> [[Messier 98|M98]] (NGC 4192), a bright, elongated spiral galaxy seen nearly edge-on, appears elliptical because of its unusual angle. The magnitude-10 galaxy has no [[redshift]].{{sfn|Burnham|2013|p=682}} [[Messier 99|M99]] (NGC 4254) is a [[spiral galaxy]] seen face-on. Like M98 it is of magnitude-10 and has an unusually long arm on its west side. Four supernovae have been observed in the galaxy.<ref>{{citation
 | title=List of Supernovae | publisher=IAU
 | work=Central Bureau for Astronomical Telegrams
 | url=http://www.cbat.eps.harvard.edu/lists/Supernovae.html
 | access-date=2018-12-19 }}</ref><ref name="Vollmer2005">{{Cite journal
 | last1=Vollmer | first1=B. | last2=Huchtmeier | first2=W.
 | last3=van Driel | first3=W. | date=September 2005
 | journal=Astronomy and Astrophysics
 | volume=439 | issue=3 | pages=921–933
 | title=NGC 4254: a spiral galaxy entering the Virgo cluster
 | bibcode = 2005A&A...439..921V | arxiv=astro-ph/0505021
 | doi=10.1051/0004-6361:20041350 | s2cid=17414818 }}</ref><ref name=Fairall1975>{{citation
 | first1=A. P. | last1=Fairall
 | title=The spectrum of the type II supernova 1967h in NGC 4254
 | journal=Monthly Notes of the Astronomical Society of South Africa
 | volume=34 | issue=7–8 | date=August 1975 | pages=94–98
 | bibcode= }}</ref> [[Messier 100|M100]] (NGC 4321), a magnitude-nine spiral galaxy seen face-on, is one of the cluster's brightest.<ref name="m100">{{cite web | url =http://messier.seds.org/m/m100.html|title=Messier 100 |publisher=The Messier Catalog| access-date =24 November 2016}}</ref> Photographs reveal a brilliant core, two prominent spiral arms, an array of secondary arms and several [[dust lane]]s.

==== Other galaxies ====
[[Image:Blackeyegalaxy.jpg|thumb|M64 (Black Eye Galaxy)]]
M64 (NGC 4826) is known as the [[Black Eye Galaxy]] because of the prominent dark [[dust lane]] in front of the galaxy's bright nucleus. Also known as the Sleeping Beauty and Evil Eye galaxy,<ref>{{cite news | url =http://www.universetoday.com/37593/messier-64/|title=Messier 64|work=[[Universe Today]]| author=Tammy Plotner| access-date =19 November 2016}}</ref> it is about 17.3 million light-years away.<ref name=Tully2016>{{citation
 | last1=Tully | first1=R. Brent | last2=Courtois | first2=Hélène M.
 | last3=Sorce | first3=Jenny G. | display-authors=1
 | title=Cosmicflows-3 | journal=The Astronomical Journal
 | volume=152 | issue=2 | id=50 | pages=21 | date=August 2016
 | doi=10.3847/0004-6256/152/2/50 | bibcode=2016AJ....152...50T
 | arxiv=1605.01765 | s2cid=250737862 | postscript=. | doi-access=free }}</ref> Recent studies indicate that the [[Interstellar medium|interstellar gas]] in the galaxy's outer regions rotates in the opposite direction from that in the inner regions, leading astronomers to believe that at least one [[satellite galaxy]] [[galactic merger|collided]] with it less than a billion years ago. All other evidence of the smaller galaxy has been assimilated. At the interface between the clockwise- and counterclockwise-rotating regions are many new [[nebula]]e and young stars.<ref name="objects"/>

[[NGC 4314]] is a face-on [[barred spiral galaxy]] at a distance of 40 million light-years. It is unique for its region of intense star formation, creating a ring around its nucleus which was discovered by the [[Hubble Space Telescope]]. The galaxy's prodigious star formation began five million years ago, in a region with a diameter of 1,000 light-years. The core's structure is also unique because the galaxy has spiral arms which feed gas into the bar.<ref name="objects"/>

[[NGC 4414]] is an [[unbarred spiral galaxy|unbarred spiral]] [[flocculent galaxy]] about 62 million light-years away. It is one of the closest flocculent spiral galaxies.<ref>{{cite web | url =https://apod.nasa.gov/apod/ap020403.html|title=NGC 4414: A Flocculent Spiral Galaxy |publisher=[[NASA]]| date=3 April 2002| access-date =19 November 2016}}</ref>

[[NGC 4565]] is an edge-on spiral galaxy which appears superimposed on the Virgo Cluster. NGC 4565 has been nicknamed the Needle Galaxy because when seen in full, it appears as a narrow streak of light.<ref>{{cite news|title=A Galactic Disc, Edge-on and Up Close|url=http://www.spacetelescope.org/images/potw1228a/|access-date=9 July 2012|newspaper=ESA/Hubble Picture of the Week}}</ref> Like many edge-on spiral galaxies, it has a prominent dust lane and a central bulge. NGC 4565 has at least two [[satellite galaxies]], and one of them is [[interacting galaxies|interacting]] with it.<ref>[http://adsabs.harvard.edu/abs/2012ApJ...760...37Z HALOGAS: H I Observations and Modeling of the Nearby Edge-on Spiral Galaxy NGC 4565]</ref>

[[NGC 4651]], about the size of the [[Milky Way]], has tidal [[stellar stream]]s gravitationally stripped from a smaller, satellite galaxy.<ref name="apod">{{cite web | url =https://apod.nasa.gov/apod/ap140702.html|title=Astronomy Picture of the Day|publisher=[[NASA]]| access-date =18 November 2016}}</ref> It is about 62 million light-years away.<ref name="apod"/> It is located on the outskirts of the cluster,<ref name="Koopmann2004">
{{cite journal
| last1 = Koopmann
| first1 = R.
| last2 = Kenney
| first2 = J. D. P.
| year = 2004
| title = Hα Morphologies and Environmental Effects in Virgo Cluster Spiral Galaxies
| journal = The Astrophysical Journal
| volume = 613
| issue= 2
| pages = 866–885
| bibcode = 2004ApJ...613..866K
| doi = 10.1086/423191
|arxiv = astro-ph/0406243 | s2cid = 17519217
}}</ref> and is also known as the Umbrella Galaxy. Unlike the other spiral galaxies in the cluster, NGC 4651 is rich in neutral hydrogen, which also extends beyond the [[visible light|optical]] disk.<ref name=Chung2009>
{{cite journal
 |last1=Chung |first1=A. |last2=Van Gorkom |first2=J.H. |last3=Kenney |first3=J.F.P. |last4=Crowl |first4=Hugh |last5=Vollmer |first5=B.
 |year=2009
 |title=VLA Imaging of Virgo Spirals in Atomic Gas (VIVA). I. The Atlas and the H I Properties 
 |journal= The Astronomical Journal
 |volume=138 |issue=6 |pages=1741–1816
 |bibcode=2009AJ....138.1741C
 |doi=10.1088/0004-6256/138/6/1741
|doi-access=free }}</ref> Its [[star formation]] is typical for a galaxy of its type.<ref name=Koopmann2004/>

Spiral galaxy [[Malin 1]] discovered in 1986 is the first-known giant [[low-surface-brightness galaxy]].<ref name="malin1">{{Cite journal|title=On the classification of UGC 1382 as a giant low surface brightness galaxy|journal=The Astrophysical Journal|volume=826|issue=2|pages=210| author1=Lea M. Z. Hagen |author2=Mark Seibert |author3=Alex Hagen |author4=Kristina Nyland |author5=James D. Neill |author6=Marie Treyer |author7=Lisa M. Young |author8=Jeffrey A. Rich |author9=Barry F. Madore|doi=10.3847/0004-637X/826/2/210|date=7 July 2016|arxiv = 1607.02147 |bibcode = 2016ApJ...826..210H |s2cid=28203497 |doi-access=free }}</ref> With [[UGC 1382]], it is also one of the largest low-surface-brightness galaxies.<ref name="malin1"/>

In 2006 a [[dwarf galaxy]], also named [[Coma Berenices (dwarf galaxy)|Coma Berenices]], was discovered in the constellation from data obtained by the [[Sloan Digital Sky Survey]].<ref>{{Cite journal | last1 = Belokurov | first1 = V. | last2 = Zucker | first2 = D. B. | last3 = Evans | first3 = N. W. | last4 = Kleyna | first4 = J. T. | last5 = Koposov | first5 = S. | last6 = Hodgkin | first6 = S. T. | last7 = Irwin | first7 = M. J. | last8 = Gilmore | first8 = G. |author-link8 = Gerard F. Gilmore| last9 = Wilkinson | first9 = M. I. | last10 = Fellhauer | doi = 10.1086/509718 | first10 = M. | last11 = Bramich | first11 = D. M. | last12 = Hewett | first12 = P. C. | last13 = Vidrih | first13 = S. | last14 = De Jong | first14 = J. T. A. | last15 = Smith | first15 = J. A. | last16 = Rix | first16 = H. -W. | last17 = Bell | first17 = E. F. | last18 = Wyse | first18 = R. F. G. | last19 = Newberg | first19 = H. J. | last20 = Mayeur | first20 = P. A. | last21 = Yanny | first21 = B. | last22 = Rockosi | first22 = C. M. |author-link22=Constance M. Rockosi| last23 = Gnedin | first23 = O. Y. | last24 = Schneider | first24 = D. P. | last25 = Beers | first25 = T. C. | last26 = Barentine | first26 = J. C. | last27 = Brewington | first27 = H. | last28 = Brinkmann | first28 = J. | last29 = Harvanek | first29 = M. | last30 = Kleinman | first30 = S. J. | title = Cats and Dogs, Hair and a Hero: A Quintet of New Milky Way Companions | journal = The Astrophysical Journal | volume = 654 | issue = 2 | pages = 897–906 | year = 2007 |arxiv = astro-ph/0608448 |bibcode = 2007ApJ...654..897B  | s2cid = 18617277 }}</ref> The galaxy is a faint satellite of the Milky Way. It is one of the faintest satellites of the [[Milky Way]] - its integrated [[luminosity]] is about {{val|3700}} times that of the Sun (absolute [[visible magnitude]] of about −4.1), which is lower than many [[globular cluster]]s.<ref name=Martin2007>{{Cite journal | last1 = Martin | first1 = N. F. | last2 = De Jong | first2 = J. T. A. | last3 = Rix | first3 = H. W. | doi = 10.1086/590336 | title = A Comprehensive Maximum Likelihood Analysis of the Structural Properties of Faint Milky Way Satellites | journal = The Astrophysical Journal | volume = 684 | issue = 2 | pages = 1075–1092 | year = 2008 |arxiv = 0805.2945 |bibcode = 2008ApJ...684.1075M | s2cid = 17838966 }}</ref> A high mass to light ratio may mean that the satellite has large amounts of [[dark matter]].<ref name=Simon2007>{{Cite journal | last1 = Simon | first1 = J. D. | last2 = Geha | first2 = M.|author2-link= Marla Geha | doi = 10.1086/521816 | title = The Kinematics of the Ultra-faint Milky Way Satellites: Solving the Missing Satellite Problem | journal = The Astrophysical Journal | volume = 670 | pages = 313–331 | year = 2007 | issue = 1 |arxiv = 0706.0516 |bibcode = 2007ApJ...670..313S | s2cid = 9715950 }}</ref>

<gallery mode="packed">
File:NGC 4789A, a subtle swarm.jpg|Dwarf irregular galaxy [[NGC 4789A]]<ref>{{cite web|title=A subtle swarm|url=https://www.spacetelescope.org/images/potw1646a/|website=www.spacetelescope.org|access-date=5 December 2016}}</ref>|alt=Diffuse galaxy
File:Needle Galaxy 4565.jpeg|alt=Galaxy resembling an angled needle|NGC 4565 (Needle Galaxy)
File:Small ngc4651.jpg|alt=Spiral galaxy with streams of light|NGC 4651, with umbrella-shaped stellar streams
File:NGC4495 - Iotw2241a.jpg|The [[constellation]] Coma Berenices hosts the galaxy [[NGC 4495]] among myriad other astronomical objects.
File: A jellyfish galaxy adrift (potw2321a).jpg|The jellyfish galaxy JW39 hangs serenely in this image from the NASA/ESA Hubble Space Telescope. This galaxy lies over 900 million light-years away in the constellation Coma Berenices.

</gallery>

=== Quasars ===
[[HS 1216+5032]] is a bright, [[Gravitational lens|gravitationally lensed]] pair of [[quasar]]s.<ref>{{cite book | author1=Wolfgang Steinicke |author2=Richard Jakiel| title =Galaxies and How to Observe Them| url=https://archive.org/details/galaxieshowtoobs0000stei| url-access=registration| publisher =Springer Science & Business Media| year =2007| page =[https://archive.org/details/galaxieshowtoobs0000stei/page/50 50]| isbn =978-1-84628-699-5}}</ref> [[W Comae Berenices]] (or ON 231), a [[blazar]] in the constellation's northwest, was originally designated a variable star and later found to be a [[BL Lacertae object]].{{sfn|Mobberley|2009|p=168}} As of 2009, it had the most intense [[gamma ray]] spectrum of the sixty known gamma-ray blazars.{{sfn|Mobberley|2009|p=168}}

=== Gamma-ray bursts ===
Some [[gamma-ray burst]]s occurred in Coma Berenices, particularly [[GRB 050509B]] on 9 May 2005<ref name="sd">{{cite web | url =https://www.sciencedaily.com/releases/2010/04/100419173012.htm|title=NASA's Swift catches 500th gamma-ray burst|website=[[ScienceDaily]]| date=25 April 2010| access-date =11 December 2016}}</ref> and [[GRB 080607]] on 7 June 2008.<ref>{{cite web | url =https://www.nasa.gov/mission_pages/swift/bursts/molecules_host.html |title=Gamma-Ray Burst Offers First Peek at a Young Galaxy's Star Factory|publisher=[[NASA]]| author=Francis Reddy| access-date =11 December 2016}}</ref> GRB 050509B, which lasted only 0.03 second, became the first short burst with a detected [[Gamma-ray burst#Afterglow|afterglow]].<ref name="sd"/>

=== Meteor shower ===
The [[Coma Berenicids]] meteor shower peaks around 18 January.<ref name="ut"/> Despite the shower's low intensity (averaging one or two meteors per hour) its meteors are some of the fastest, with speeds up to {{convert|65|km/s}}.<ref name="ut">{{cite news | url =http://www.universetoday.com/20405/coma-berenices/|title=Coma Berenices|work=[[Universe Today]]|author=Tammy Plotner| date= 24 Dec 2015| access-date =15 Aug 2016}}</ref>

== In culture ==
[[File:The hair of Berenice, by Luis Ricardo Faléro.jpg|thumb|160px|alt=Print of two female nudes in the heavens|[[Luis Ricardo Falero]]'s ''The Hair of Berenice'' (1886)]]
Since Callimachus' poem, Coma Berenices has been occasionally featured in culture. [[Alexander Pope]] alludes to the legend in the ending of ''[[The Rape of the Lock]]'', in which the titular hair is placed among the stars. (The poem would go on to provide the names of some of the [[moons of Uranus]].) In 1886, Spanish artist [[Luis Ricardo Falero]] created a [[mezzotint]] print personifying Coma Berenices alongside Virgo and Leo.<ref>{{cite web | url =http://www.britishmuseum.org/research/collection_online/collection_object_details.aspx?objectId=1611047&partId=1&people=125549&peoA=125549-2-23&page=1|title=La chevelure de Berenice|publisher=[[British Museum]]| access-date =24 November 2016}}</ref> In 1892, the Russian poet [[Afanasy Fet]] made the constellation the subject of his short poem, composed for the Countess Natalya Sollogub.<ref>{{cite web | url =http://poesias.ru/rus-stihi/stihi-fet/stihi-fet10092.shtml |title=Стихотворение Фета А.А. "Графине Н. М. Соллогуб (О, Береника! Сердцем чую)"|publisher=Poesias.ru| language=ru| access-date =10 January 2017}}</ref> The Swedish poet [[Gunnar Ekelöf]] wrote the lines "Your friend the comet combed his hair with the [[Leonids]] / Berenice let her hair hang down from the sky" in a 1933 poem.<ref>{{cite book |last=Ekelöf |first=Gunnar |author-link=Gunnar Ekelöf |title=En självbiografi: efterlämnade brev och anteckningar |url=https://books.google.com/books?id=6ISgAgAAQBAJ&pg=PA126 |year=2013|publisher=Albert Bonniers Förlag |isbn=978-91-0-013697-0 |page=126 |language=sv |quote=Din vän kometen kammade håret med Leoniderna / Berenice låt sitt hår hänga ner från himlen}}</ref> American writer and folksinger [[Richard Fariña]] mentions Coma Berenices in his 1966 novel ''[[Been Down So Long It Looks Like Up to Me|Been Down So Long It Looks Like Up To Me]]'', sardonically writing about content typical to upper-level astronomy coursework at [[Cornell University|Cornell]]: "It's the advanced courses give you trouble. Relativity principles, spiral nebula in Coma Berenices, that kind of hassle". The Bolivian poet, [[Pedro Shimose]], makes Coma Berenices the home address of his "Señorita NGC 4565" in his poem "Carta a una estrella que vive en otra constelación" ("Letter to a star who lives in another constellation"), included in his 1967 collection, "Sardonia".<ref>(La Paz:  Universidad Mayor de San Andrés, 1967).</ref> "<ref>{{Cite book|url=https://books.google.com/books?id=FJoAjhihQhwC|title=Been Down So Long It Looks Like Up to Me|last=Farina|first=Richard|date=1996-05-01|publisher=Penguin|isbn=978-1-101-54952-0|page=27|language=en}}</ref> The Irish poet [[W. B. Yeats]], in his poem "Her Dream", refers to "Berenice's burning hair" being "nailed upon the night". Francisco Guerrero, a 20th-century Spanish composer, wrote an orchestral work on the constellation in 1996. In 1999 Irish artist [[Alice Maher]] made a series of four oversize drawings, entitled ''Coma Berenices'', of entwining black hair coils.<ref>{{cite web| url =http://www.sothebys.com/en/auctions/ecatalogue/lot.84.html/2006/post-war-and-contemporary-irish-art-l06625| title =Coma Berenices (1 of 4)| publisher =[[Sotheby's]]| access-date =24 November 2016| archive-date =27 March 2019| archive-url =https://web.archive.org/web/20190327134632/http://www.sothebys.com/en/auctions/ecatalogue/lot.84.html/2006/post-war-and-contemporary-irish-art-l06625| url-status =dead}}</ref>

==Notes==
{{notelist}}

== See also ==
* [[Coma Star Cluster]]
* [[Coma Berenices in Chinese astronomy]]
* [[IC 4141]]

== References ==
{{Reflist|refs=

<ref name=Kirkpatrick2024>{{cite journal |last1=Kirkpatrick |first1=J. Davy |last2=Marocco |first2=Federico |display-authors=etal |date=April 2024 |title=The Initial Mass Function Based on the Full-sky 20 pc Census of ~3600 Stars and Brown Dwarfs |journal=[[The Astrophysical Journal Supplement Series]] |volume=271 |issue=2 |pages=55 |doi=10.3847/1538-4365/ad24e2 |doi-access=free |arxiv=2312.03639 |bibcode=2024ApJS..271...55K}}</ref>

}}

== External links ==
{{Commons}}
* [http://www.allthesky.com/constellations/comaberenices/ The Deep Photographic Guide to the Constellations: Coma Berenices]
* [http://astrojan.nhely.hu/coma.htm The clickable Coma Berenices]
* {{Cite EB1911|wstitle=Coma Berenices}}

{{Stars of Coma Berenices}}
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{{Portal bar|Astronomy|Stars|Outer space}}

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{{DEFAULTSORT:Coma Berenices}}
[[Category:Coma Berenices| ]]
[[Category:Northern constellations]]
[[Category:Ptolemaic Kingdom in popular culture]]