{{short description|Star in the constellation Centaurus}} {{about|r Centauri|the variable star|R Centauri}} {{Starbox begin | name = r Centauri }} {{Starbox observe | epoch = J2000.0 | constell = [[Centaurus]]<ref name=xhip/> | ra = {{RA|13|16|53.13228}}<ref name=GaiaDR2/> | dec = {{DEC|−31|30|22.3332}}<ref name=GaiaDR2/> | appmag_v = +5.12<ref name=Bluhm2016/> }} {{Starbox character | type = [[red clump]]<ref name=Alves2000/> | class = K1III<ref name=houk1979/> | b-v = 0.94<ref name=Bluhm2016/> | u-b = | variable = }} {{Starbox astrometry | radial_v = +12.9<ref name=Wilson1953/> | prop_mo_ra = +34.179<ref name=GaiaDR2/> | prop_mo_dec = −47.615<ref name=GaiaDR2/> | parallax = 12.7119 | p_error = 0.1426 | parallax_footnote = <ref name=GaiaDR2/> | absmag_v = +0.61<ref name=xhip/> }} {{Starbox detail | source = <ref name=Bluhm2016/> | mass = {{Val|2.71|0.19}} | radius = {{Val|10.8|0.8}} | luminosity = {{Val|67.11|6.91}} | temperature = 5,060 | gravity = 2.63 | metal_fe = −0.15<ref name=Alves2000/> | rotational_velocity = | age_gyr = }} {{Starbox catalog | names = {{odlist | B=r Cen | CD=−30°10457 | FK5=1342 | HD=115310 | HIP=64803 | HR=5006 | SAO=204312 | GC=17968 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+115310 }} {{Starbox end}}

'''HD 115310''', also known by its [[Bayer designation]] '''r Centauri''', is a [[star]] in the southern [[constellation]] [[Centaurus]]. It is an orange-hued star that is visible to the naked eye with an [[apparent visual magnitude]] that ranges around +5.12.<ref name=Bluhm2016/> Based upon [[stellar parallax|parallax measurements]], it is located approximately 257&nbsp;[[light year]]s away. It is drifting further from the Sun with a [[radial velocity]] of +12.9&nbsp;km/s.<ref name=Wilson1953/>

This object is an aging [[K-type star|K-type]] [[giant star]] with a [[stellar classification]] of K1III.<ref name=houk1979/> It is classified as a [[red clump]] giant, suggesting it is on the [[horizontal branch]] undergoing [[stellar core|core]] [[helium fusion]].<ref name=Alves2000/> The star has 2.7 times the [[mass of the Sun]] and has expanded to 11 times the [[Sun's radius]]. It is radiating 67 times the [[luminosity of the Sun]] from its swollen [[photosphere]] at an [[effective temperature]] of 5,060&nbsp;K.<ref name=Bluhm2016/>

==References== {{Reflist|colwidth=30em|refs=

<ref name=GaiaDR2>{{cite DR2|6181513577482286336}}</ref>

<ref name=Alves2000>{{citation | last1=Alves | first1=David R. | title=K-Band Calibration of the Red Clump Luminosity | journal=The Astrophysical Journal | volume=539 | issue=2 | pages=732–741 | date=August 2000 | doi=10.1086/309278 | bibcode=2000ApJ...539..732A | arxiv=astro-ph/0003329 | s2cid=16673121 | postscript=. }}</ref>

<ref name=Wilson1953>{{citation | last=Wilson | first=Ralph Elmer | year=1953 | title=General catalogue of stellar radial velocities | journal=Washington | pages=0 | publisher=Carnegie Institution of Washington | bibcode=1953GCRV..C......0W | postscript=. }}</ref>

<ref name=houk1979>{{citation | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=3 | last1=Houk | first1=Nancy | location=Ann Arbor, Michigan | publisher=Dept. of Astronomy, University of Michigan | year=1979 | bibcode=1982mcts.book.....H | postscript=. }}</ref>

<ref name=SIMBAD>{{cite simbad | title=HD 115310 | access-date=2019-10-06 }}</ref>

<ref name=Bluhm2016>{{citation | title=New spectroscopic binary companions of giant stars and updated metallicity distribution for binary systems | display-authors=1 | last1=Bluhm | first1=P. | last2=Jones | first2=M. I. | last3=Vanzi | first3=L. | last4=Soto | first4=M. G. | last5=Vos | first5=J. | last6=Wittenmyer | first6=R. A. | last7=Drass | first7=H. | last8=Jenkins | first8=J. S. | last9=Olivares | first9=F. | last10=Mennickent | first10=R. E. | last11=Vučković | first11=M. | last12=Rojo | first12=P. | last13=Melo | first13=C. H. F. | journal=Astronomy & Astrophysics | volume=593 | id=A133 | pages=17 | date=October 2016 | arxiv=1608.08260 | bibcode=2016A&A...593A.133B | doi=10.1051/0004-6361/201628459 | s2cid=56087624 | postscript=. }}</ref>

<ref name=xhip>{{cite XHIP|64803|mode=cs2|postscript=.}}</ref>

}}

{{Stars of Centaurus}}

{{DEFAULTSORT:Hd 115310}} <!-- Properties --> [[Category:K-type giants]] [[Category:Horizontal-branch stars]] <!-- Identifiers --> [[Category:Centaurus]] [[Category:Bayer objects|Centauri, r]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|115310]] [[Category:Bright Star Catalogue objects|5006]] [[Category:Hipparcos objects|064803]]