Editing Coma Berenices (section)

=== 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>