{{short description|Star in the constellation Coma Berenices}} {{Starbox begin}} {{Starbox image | image = [[File:Melotte111 karte.png|240px]] | caption = Map showing location of 24 Comae Berenices }} {{Starbox observe 2s | epoch = J2000.0 | constell = [[Coma Berenices]] | component1 = A | ra1 = {{RA|12|35|07.76130}}<ref name=GaiaDR2/> | dec1 = {{DEC|+18|22|37.4133}}<ref name=GaiaDR2/> | appmag_v1 = 5.03<ref name=Anderson2012/> | component2 = B | ra2 = {{RA|12|35|06.34558}}<ref name=GaiaDR2/> | dec2 = {{DEC|+18|22|37.5320}}<ref name=GaiaDR2/> | appmag_v2 = 6.57<ref name=Anderson2012/> }} {{Starbox character | component1 = A | type = | class = K0II-III<ref name=Yoss1997/> | b-v = {{Val|1.152|0.018}}<ref name=Anderson2012/> | u-b = | r-i = | variable = | component2 = B | type2 = A9V<ref name=Yoss1997/> | class2 = | b-v2 = {{Val|0.265|0.015}}<ref name=Anderson2012/> }} {{Starbox astrometry | component1 = A | radial_v = {{Val|+3.03|0.10}}<ref name=Anderson2012/> | prop_mo_ra = −3.719<ref name=GaiaDR2/> | prop_mo_dec = +23.106<ref name=GaiaDR2/> | parallax = 8.5745 | p_error = 0.1996 | parallax_footnote = <ref name=GaiaDR2/> | absmag_v = 0.30<ref name=mcwilliam1990/> | component2 = B | radial_v2 = {{Val|+4.90|0.50}}<ref name=Anderson2012/> | prop_mo_ra2 = −2.320<ref name=GaiaDR2/> | prop_mo_dec2 = +21.236<ref name=GaiaDR2/> | parallax2 = 8.8346 | p_error2 = 0.0695 | parallax_footnote2 = <ref name=GaiaDR2/> | absmag_v2 = }} {{Starbox orbit | reference = <ref name=Lester2022/> | primary = Ba | name = Bb | period = <!--Period (in years)--> | period_unitless = {{Val|7.336673|0.000087|u=days}} | axis = <!--Semimajor axis (in arcseconds)--> | axis_unitless = {{val|1.007|0.037|u=mas}} | eccentricity = {{Val|0.2585|0.0012}} | inclination = {{Val|61.40|3.89}} | node = {{val|136.17|2.86}} | periastron = {{Val|2459361.967|0.011|ul=JD|fmt=commas}} | periarg_primary = {{Val|302.33|0.28}} | k1 = {{Val|68.16|0.09}} | k2 = {{Val|81.28|0.20}} }} {{Starbox detail | component1 = A | mass = 4.40<ref name=Tokovinin2008/> | radius = {{Val|19.95|0.69|2.58}}<ref name=GaiaDR2/> | gravity = 2.50<ref name=mcwilliam1990/> | metal_fe = −0.09<ref name=Malagnini2000/> | age_myr = | luminosity = {{Val|173.3|4.6}}<ref name=GaiaDR2/> | temperature = {{Val|4688|337|79|fmt=commas}}<ref name=GaiaDR2/> | rotational_velocity = }} {{Starbox detail|no_heading=y | component1 = Ba | mass = {{val|1.838|0.218}}<ref name=Lester2022/> | radius = {{Val|2.28|0.06}}<ref name=Lester2022/> | gravity = {{Val|3.86|0.01}}<ref name=Lester2022/> | metal_fe = 0.54<ref name=Stickland1973/> | age_myr = | luminosity = {{Val|15.6|1.3}}<ref name=Lester2022/> | temperature = {{Val|7630|120|fmt=commas}}<ref name=Lester2022/> | rotational_velocity = {{Val|14.5|1.5}} | component2 = Bb | mass2 = {{Val|1.541|0.184}}<ref name=Lester2022/> | radius2 = {{Val|1.70|0.07}}<ref name=Lester2022/> | gravity2 = {{Val|4.09|0.02}}<ref name=Lester2022/> | metal_fe2 = 0.54<ref name=Stickland1973/> | age_myr2 = | luminosity2 = {{val|7.2|0.9}}<ref name=Lester2022/> | temperature2 = {{Val|7180|140|fmt=commas}}<ref name=Lester2022/> | rotational_velocity2 = {{Val|14.2|1.1}}<ref name=Lester2022/> }} {{Starbox catalog | names = {{odlist | F=24 Com | BD=+19°2584 | FK5=473 | WDS=02338-2814 }} | component1 = A | names1 = {{odlist | HD=109511 | HIP=61418 | HR=4792 | SAO=100160 | GC=17147 | NSV=5748 }}<ref name=SIMBADa/> | component2 = B | names2 = {{odlist | HD=109510 | HIP=61415 | HR=4791 | SAO=100159 | GC=17146 }}<ref name=SIMBADb/> }} {{Starbox reference | Simbad = 24+Com+A |sn=A | Simbad2 = 24+Com+B |sn2=B }} {{Starbox end}}
'''24 Comae Berenices''' is a [[triple star]] system in the northern [[constellation]] of [[Coma Berenices]]. It is visible to the naked eye, with the brightest component being an orange-hued [[star]] with an [[apparent visual magnitude]] of 5.03.<ref name=Anderson2012/> The system is located at a distance of approximately 269 [[light-year]]s from the [[Sun]] based on [[stellar parallax|parallax]], and is drifting further away with [[radial velocities]] of 3–5 km/s.<ref name=Anderson2012/>
This system can be resolved in a [[telescope]] as a pair of stars with an [[angular separation]] of {{Val|20.2|ul=arcsecond}} along a [[position angle]] of 272°, as of 2018.<ref name=WDSC2014/> They share a common motion through space and thus appear to be physically associated,<ref name=Mayor1987/> with a wide [[projected separation]] of {{Val|1400|ul=AU|fmt=commas}} or greater.<ref name=Abt1988/> If they are bound in an orbit, the estimated [[orbital period|period]] is approximately 28,000 years.<ref name=Tokovinin2008/>
The brighter member of this system is an aging [[giant star|giant]] or [[bright giant]] star with a [[stellar classification]] of K0II-III.<ref name=Yoss1997/> It has exhausted the supply of hydrogen at its [[stellar core|core]] and expanded to 20<ref name=GaiaDR2/> times the [[solar radius|girth of the Sun]]. This is a suspected [[variable star|variable]] that has been recorded ranging in brightness from magnitude 4.98 down to 5.06.<ref name=Samus2017/> The star is radiating 173<ref name=GaiaDR2/> times the [[luminosity of the Sun]] from its swollen [[photosphere]] at an [[effective temperature]] of 4,688 K.<ref name=GaiaDR2/>
The fainter component at magnitude 6.57<ref name=Anderson2012/> is a double-lined [[spectroscopic binary]] with an [[orbital period]] of 7.33 days and an [[orbital eccentricity|eccentricity]] of 0.26.<ref name=Mayor1987/> The primary member of this pair is an [[A-type main-sequence star]] with a [[stellar classification]] of A9V.<ref name=Yoss1997/> It is a metallic-lined [[Am star]]<ref name=chen2017/> with 2.2 times the [[radius of the Sun]].<ref name=Lester2022/> The stars radiate about 16 and 7 times the [[Sun's luminosity]] from its [[photosphere]], respectively, at [[effective temperature]]s of 7,630 and 7180 K, respectively.<ref name=Lester2022/> Both have relatively low [[projected rotational velocity]] of around 14 km/s,<ref name=Lester2022/> and it is suspected the rotations of this binary system may be synchronized.<ref name=Stickland1973/> The system is a source for [[X-ray astronomy|X-ray emission]], which is most likely coming from the secondary.<ref name=Schröder2007/>
==References== <references> <ref name=SIMBADa>{{cite simbad | title=24 Com A | accessdate=2019-10-30 }}</ref> <ref name=SIMBADb>{{cite simbad | title=24 Com B | accessdate=2019-10-30 }}</ref>
<ref name=GaiaDR2>{{cite DR2}} * [http://vizier.u-strasbg.fr/viz-bin/VizieR-S?Gaia%20DR2%3947649169267207296 Component A] * [http://vizier.u-strasbg.fr/viz-bin/VizieR-S?Gaia%20DR2%3947647760517933824 Component B] </ref>
<ref name=Abt1988>{{citation | title=Maximum Separations among Cataloged Binaries | last1=Abt | first1=Helmut A. | postscript=. | journal=Astrophysical Journal | volume=331 | page=922 | date=August 1988 | doi=10.1086/166609 | bibcode=1988ApJ...331..922A }}</ref>
<ref name=Schröder2007>{{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 | pages=677–684 | date=November 2007 | doi=10.1051/0004-6361:20077429 | bibcode=2007A&A...475..677S | doi-access=free }}</ref>
<ref name=Samus2017>{{citation | display-authors=1 | title=General catalogue of variable stars: Version GCVS 5.1 | 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 | journal=Astronomy Reports | volume=61 | issue=1 | pages=80 | year=2017 | postscript=. | doi=10.1134/S1063772917010085 | bibcode=2017ARep...61...80S | s2cid=125853869 }}</ref>
<ref name=Malagnini2000>{{citation | postscript=. | title=Observations and Atmospheric Parameters of Super-Metal-rich Candidates | journal=The Publications of the Astronomical Society of the Pacific | volume=112 | issue=777 | pages=1455 | year=2000 | display-authors=1 | last1=Malagnini | first1=M. L. | last2=Morossi | first2=C. | last3=Buzzoni | first3=A. | last4=Chavez | first4=M. | doi=10.1086/317714 | bibcode=2000PASP..112.1455M | doi-access=free }}</ref>
<ref name=Tokovinin2008>{{citation | title=Comparative statistics and origin of triple and quadruple stars | last1=Tokovinin | first1=A. | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=925–938 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13613.x | doi-access=free | postscript=. | bibcode=2008MNRAS.389..925T | arxiv=0806.3263 | s2cid=16452670 }}</ref>
<ref name=WDSC2014>{{citation | display-authors=1 | last1=Mason | first1=B. D. | last2=Wycoff | first2=G. L. | last3=Hartkopf | first3=W. I. | last4=Douglass | first4=G. G. | last5=Worley | first5=C. E. | title=The Washington Visual Double Star Catalog | journal=The Astronomical Journal | year=2014 | volume=122 | issue=6 | page=3466 | bibcode=2001AJ....122.3466M | doi=10.1086/323920 | url=http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds | access-date=2015-07-22 | postscript=. | doi-access=free }}</ref>
<ref name=chen2017>{{citation | display-authors=1 | last1=Chen | first1=P. S. | last2=Liu | first2=J. Y. | last3=Shan | first3=H. G | title=A New Photometric Study of Ap and Am Stars in the Infrared | journal=The Astronomical Journal | postscript=. | volume=153 | issue=5 | pages=218 | year=2017 | bibcode=2017AJ....153..218C | doi=10.3847/1538-3881/aa679a | doi-access=free }}</ref>
<ref name=Mayor1987>{{citation | title=The frequency of triple and multiple stellar systems | last1=Mayor | first1=M. | last2=Mazeh | first2=T. | journal=Astronomy and Astrophysics | volume=171 | pages=157−177 | date=January 1987 | bibcode=1987A&A...171..157M | postscript=. }}</ref>
<ref name=Anderson2012>{{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | postscript=. | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>
<ref name=Yoss1997>{{citation | title=Radial Velocities and DDO, BV Photometry of Henry Draper G5-M Stars Near the North Galactic Pole | last1=Yoss | first1=K. M. | last2=Griffin | first2=R. F. | journal=Journal of Astrophysics and Astronomy | volume=18 | page=161 | date=September 1997 | issue=2–3 | postscript=. | doi=10.1007/BF02714877 | bibcode=1997JApA...18..161Y | s2cid=123221180 }}</ref>
<ref name=Stickland1973>{{citation | title=On the atmospheric abundances of seven Am SB2 systems | last=Stickland | first=D. J. | postscript=. | journal=Monthly Notices of the Royal Astronomical Society | volume=161 | page=193 | year=1973 | issue=2 | doi=10.1093/mnras/161.2.193 | bibcode=1973MNRAS.161..193S | doi-access=free }}</ref>
<ref name=mcwilliam1990>{{citation | postscript=. | title=High-Resolution Spectroscopic Survey of 671 GK Giants. I. Stellar Atmosphere Parameters and Abundances | last=McWilliam | first=Andrew | journal=The Astrophysical Journal Supplement Series | volume=74 | pages=1075 | year=1990 | bibcode=1990ApJS...74.1075M | doi=10.1086/191527 | doi-access=free}}</ref>
<ref name=Lester2022>{{citation | postscript=. | title=Visual Orbits of Spectroscopic Binaries with the CHARA Array. IV. HD 61859, HD 89822, HD 109510, and HD 191692 | display-authors=1 | last1=Lester | first1=Kathryn V. | last2=Schaefer | first2=Gail H. | last3=Fekel | first3=Francis C. | last4=Gies | first4=Douglas R. | last5=Henry | first5=Todd J. | last6=Jao | first6=Wei-Chun | last7=Paredes | first7=Leonardo A. | last8=Hubbard-James | first8=Hodari-Sadiki | last9=Farrington | first9=Christopher D. | last10=Gordon | first10=Kathryn D. | last11=Chojnowski | first11=S. Drew | last12=Monnier | first12=John D. | last13=Kraus | first13=Stefan | last14=Bouquin | first14=Jean-Baptiste Le | last15=Anugu | first15=Narsireddy | last16=Brummelaar | first16=Theo Ten | last17=Davies | first17=Claire L. | last18=Gardner | first18=Tyler | last19=Labdon | first19=Aaron | last20=Lanthermann | first20=Cyprien | last21=Setterholm | first21=Benjamin R. | journal=The Astronomical Journal | volume=164 | issue=6 | page=228 | year=2022 | bibcode=2022AJ....164..228L | arxiv=2209.09993 | doi=10.3847/1538-3881/ac9385 | s2cid=252408703 | doi-access=free }}</ref> </references>
{{Stars of Coma Berenices}} <!-- Properties -->
[[Category:K-type bright giants]] [[Category:K-type giants]] [[Category:Suspected variables]] [[Category:A-type main-sequence stars]] [[Category:Am stars]] [[Category:Spectroscopic binaries]] [[Category:Triple stars]] <!-- Identifiers --> [[Category:Coma Berenices]] [[Category:Durchmusterung objects]] [[Category:Flamsteed objects|Comae Berenices, 24]] [[Category:Henry Draper Catalogue objects|109510/1]] [[Category:Hipparcos objects|61415/61418]] [[Category:Bright Star Catalogue objects|4791/2]]