{{Short description|Star system in the constellation Coma Berenices}} {{Starbox begin}} {{Starbox observe | epoch= J2000.0 | constell = [[Coma Berenices]] | ra = {{RA|12|24|18.54890}}<ref name=dr3/> | dec = {{DEC|+26|05|54.9214}}<ref name=dr3/> | appmag_v = 5.15{{snd}}5.18<ref name=gcvs/> }} {{Starbox character | type = [[main sequence]]<ref name=dr3/> | class = A3 V<ref name=Eggleton2008/><ref name=Anderson2012/> | b-v = {{Val|0.082|0.003}}<ref name=Anderson2012/> | u-b = | variable = [[Alpha2 Canum Venaticorum variable|α{{sup|2}} CVn]]<ref name=gcvs/> }} {{Starbox astrometry | radial_v = {{Val|+0.1|0.1}}<ref name=deBruijne2012/> | prop_mo_ra = −26.158<ref name=dr3/> | prop_mo_dec = −9.385<ref name=dr3/> | parallax = 11.1318 | p_error = 0.1589 | parallax_footnote = <ref name=dr3/> | absmag_v = 0.38<ref name=Anderson2012/> }} {{Starbox orbit | reference = <ref name=Tokovinin2024/> | period = {{Val|27.25|1.76}} | axis = {{Val|0.170|0.012}} | eccentricity = {{Val|0.868|0.021}} | inclination = {{Val|32.3|7.3}} | node = {{Val|164.0|8.2}} | periastron = {{Val|2017.80|0.11|fmt=none}} | periarg = {{Val|275.1|7.1}} }} {{Starbox detail | mass = 2.83<ref name=David2015/> | radius = 3.37<ref name=tic/> | luminosity = 55<ref name=tic/> | temperature = {{Val|8846|301|fmt=commas}}<ref name=David2015/> | gravity = {{Val|3.84|0.14}}<ref name=David2015/> | metal_fe = 0.24<ref name=Anderson2012/> | rotation = 29.5 days<ref name=oelkers2018/> | rotational_velocity = 48<ref name=David2015/> | age_myr = 429<ref name=David2015/> }} {{Starbox catalog | names = {{odlist | V=GN Com | F=13 Com | BD=+26° 2344 | FK5= | GJ= | HD=107966 | HIP=60514 | HR=4717 | SAO=82291 | GC= }}<ref name=SIMBAD>{{cite simbad | title=13 Com | access-date=2018-02-17 }}</ref> }} {{Starbox reference | Simbad=13+Com }} {{Starbox end}}
'''13 Comae Berenices''' is a [[binary star]]<ref name=Eggleton2008/> system in the northern [[constellation]] of [[Coma Berenices]]. It has an [[apparent visual magnitude]] of 5.2, which is bright enough to be faintly visible to the [[naked eye]]. With an annual [[stellar parallax|parallax shift]] of {{val|11.1|ul=mas}},<ref name=dr3/> it is located around 293 [[light year]]s from the Sun. It is member of the nearby [[Coma Star Cluster]] (Melotte 111).<ref name=Casewell2006/>
The two stars of this system orbit with a period of 27.25 years and a large [[orbital eccentricity|eccentricity]] of 0.868.<ref name=Tokovinin2024/> The primary is an [[A-type main-sequence star]] with a [[stellar classification]] of A3 V.<ref name=Eggleton2008/> In 1965, Gerhard Jackisch discovered the star is a [[variable star]].<ref name="Jackisch1972"/> It was given its [[variable star designation]], GN Comae Berenices, in 1975.<ref name="Kukarkin1975"/> It is catalogued as an [[Alpha2 Canum Venaticorum variable|Alpha<sup>2</sup> Canum Venaticorum variable]].<ref name=Hoffleit1982/> Rensom (1990) listed it as a suspected [[Am star]].<ref name=Renson1990/> The system is a source of [[X-ray astronomy|X-ray emission]], which may be coming from the companion.<ref name=Schroeder2007/>
==References== <references> <ref name=dr3>{{cite Gaia DR3|4008444190824309376}}</ref>
<ref name=gcvs>{{cite journal |last1=Samus' |first1=N. N. |last2=Kazarovets |first2=E. V. |last3=Durlevich |first3=O. V. |last4=Kireeva |first4=N. N. |last5=Pastukhova |first5=E. N. |title=General catalogue of variable stars: Version GCVS 5.1 |journal=Astronomy Reports |date=2017 |volume=61 |issue=1 |page=80 |doi=10.1134/S1063772917010085 |bibcode=2017ARep...61...80S }}</ref>
<ref name=tic>{{cite journal |last1=Stassun |first1=Keivan G. |last2=Oelkers |first2=Ryan J. |last3=Paegert |first3=Martin |last4=Torres |first4=Guillermo |last5=Pepper |first5=Joshua |last6=De Lee |first6=Nathan |last7=Collins |first7=Kevin |last8=Latham |first8=David W. |last9=Muirhead |first9=Philip S. |last10=Chittidi |first10=Jay |last11=Rojas-Ayala |first11=Bárbara |last12=Fleming |first12=Scott W. |last13=Rose |first13=Mark E. |last14=Tenenbaum |first14=Peter |last15=Ting |first15=Eric B. |last16=Kane |first16=Stephen R. |last17=Barclay |first17=Thomas |last18=Bean |first18=Jacob L. |last19=Brassuer |first19=C. E. |last20=Charbonneau |first20=David |last21=Ge |first21=Jian |last22=Lissauer |first22=Jack J. |last23=Mann |first23=Andrew W. |last24=McLean |first24=Brian |last25=Mullally |first25=Susan |last26=Narita |first26=Norio |last27=Plavchan |first27=Peter |last28=Ricker |first28=George R. |last29=Sasselov |first29=Dimitar |last30=Seager |first30=S. |display-authors=1 |title=The Revised TESS Input Catalog and Candidate Target List |journal=The Astronomical Journal |date=2019 |volume=158 |issue=4 |page=138 |doi=10.3847/1538-3881/ab3467 |doi-access=free |arxiv=1905.10694 |bibcode=2019AJ....158..138S }}</ref>
<ref name=oelkers2018>{{cite journal |last1=Oelkers |first1=Ryan J. |last2=Rodriguez |first2=Joseph E. |last3=Stassun |first3=Keivan G. |last4=Pepper |first4=Joshua |last5=Somers |first5=Garrett |last6=Kafka |first6=Stella |last7=Stevens |first7=Daniel J. |last8=Beatty |first8=Thomas G. |last9=Siverd |first9=Robert J. |last10=Lund |first10=Michael B. |last11=Kuhn |first11=Rudolf B. |last12=James |first12=David |last13=Gaudi |first13=B. Scott |title=Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey |journal=The Astronomical Journal |date=2018 |volume=155 |issue=1 |page=39 |doi=10.3847/1538-3881/aa9bf4 |doi-access=free |arxiv=1711.03608 |bibcode=2018AJ....155...39O }}</ref>
<ref name="Jackisch1972">{{cite journal | last1=Jackisch | first1=G. | title=Über die Veränderlichkeit der Sterne des Spektraltyps A | journal=Astronomische Nachrichten | date=September 1972 | volume=294 | issue=1–2 | pages=1–8 | bibcode=1972AN....294....1J | doi=10.1002/asna.19722940102 }}</ref>
<ref name=Anderson2012>{{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | s2cid=119257644 | postscript=. }}</ref>
<ref name=Tokovinin2024>{{Citation |last1=Tokovinin |first1=Andrei |last2=Mason |first2=Brian D. |last3=Mendez |first3=Rene A. |last4=Costa |first4=Edgardo |date=July 2024|title=Speckle Interferometry at SOAR Telescope in 2023 |bibcode=2024AJ....168...28T |journal=The Astronomical Journal |language=en |volume=168 |issue=1 |pages=28 |doi=10.3847/1538-3881/ad4d56 |doi-access=free |issn=0004-6256}}.</ref>
<ref name=Hoffleit1982>{{citation | title=Variable stars in the General Catalogue of Trigonometric Parallaxes | last1=Hoffleit | first1=D. | journal=Bulletin d'Information du Centre de Données Stellaires | volume=23 | page=53 | date=October 1982 | bibcode=1982BICDS..23...53H | postscript=. }} See entry 2855. </ref>
<ref name=Kukarkin1975>{{citation | title=60th Name-List of Variable Stars | last1=Kukarkin | first1=B. V. | last2=Kholopov | first2=P. N. | last3=Kukarkina | first3=N. P. | last4=Perova | first4=N. B. | journal=Information Bulletin on Variable Stars | volume=961 | page=1 | date=January 1975 | bibcode=1975IBVS..961....1K | postscript=. }}</ref>
<ref name=Renson1990>{{citation | title=Liste des étoiles Ap et Am dans les amas ouverts (Edition révisée) | last1=Renson | first1=P. | language=French | journal=Bulletin d'Information du Centre de Données Stellaires | volume=38 | page=151 | date=December 1990 | bibcode=1990BICDS..38..151R | postscript=. }}</ref>
<ref name=Casewell2006>{{citation |display-authors=1 | last1=Casewell | first1=S. L. | last2=Jameson | first2=R. F. | last3=Dobbie | first3=P. D. | title=New stellar members of the Coma Berenices open star cluster | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=365 | issue=2 | pages=447–453 | date=January 2006 | doi=10.1111/j.1365-2966.2005.09689.x | doi-access=free | bibcode=2006MNRAS.365..447C | arxiv=astro-ph/0510133 | s2cid=17595520 | postscript=. }}</ref>
<ref name=Schroeder2007>{{citation | title=X-ray emission from A-type stars | last1=Schröder | first1=C. | last2=Schmitt | first2=J. H. M. M. | journal=Astronomy and Astrophysics | postscript=. | volume=475 | issue=2 | date=November 2007 | pages=677−684 | doi=10.1051/0004-6361:20077429 | bibcode=2007A&A...475..677S | doi-access=free }}</ref>
<ref name=deBruijne2012>{{citation | last1=de Bruijne | first1=J. H. J. | last2=Eilers | first2=A.-C. | title=Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project | journal=Astronomy & Astrophysics | volume=546 | id=A61 | pages=14 | date=October 2012 | doi=10.1051/0004-6361/201219219 | bibcode=2012A&A...546A..61D | arxiv=1208.3048 | s2cid=59451347 | postscript=. }}</ref>
<ref name=David2015>{{citation | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146 | arxiv=1501.03154 | s2cid=33401607 | postscript=. }}</ref>
<ref name=Eggleton2008>{{citation | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=389 | issue=2 | pages=869–879 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E | postscript=. | arxiv=0806.2878 | s2cid=14878976 }}</ref> </references>
{{Stars of Coma Berenices}}
[[Category:A-type main-sequence stars]] [[Category:Binary stars]] [[Category:Coma Berenices]] [[Category:Flamsteed objects|Comae Berenices, 13]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|107966]] [[Category:Hipparcos objects|060514]] [[Category:Bright Star Catalogue objects|4717]] [[Category:Objects with variable star designations|Comae Berenices, GN]] [[Category:Alpha2 Canum Venaticorum variables]]