Rho Centauri

{{Short description|Binary star system in the constellation Centaurus}} {{Starbox begin}} {{Starbox image | image = {{Location mark | image=Centaurus IAU.svg | float=center | width=240 | position=right | mark=Red circle.svg | mark_width=10 | mark_link=ρ Cen | x%=59.1 | y%=56.7 }} | caption = Location of ρ Centauri (circled) }} {{Starbox observe | epoch = [[J2000.0]] | constell = [[Centaurus]]<ref name=Anderson2012/> | ra = {{RA|12|11|39.12805}}<ref name=GaiaDR3/> | dec = {{DEC|−52|22|06.4067}}<ref name=GaiaDR3/> | appmag_v = +3.97<ref name=Anderson2012/> }} {{Starbox character | type = main sequence | class = B3 V<ref name=aaa216_1_44/> | b-v = {{Val|−0.156|0.008}}<ref name=Anderson2012/> | u-b = −0.650<ref name=apjs15/> | variable = }} {{Starbox astrometry | radial_v = {{Val|+15.0|4.1}}<ref name=Gontcharov2006/> | prop_mo_ra = −43.741 | prop_mo_dec = −11.771 | pm_footnote = <ref name=GaiaDR3/> | parallax = 11.8348 | p_error = 0.3746 | parallax_footnote=<ref name=GaiaDR3/> | absmag_v = −1.33<ref name=Anderson2012/> }} {{Starbox orbit | reference = <ref name=Mason2023/> | primary = A | name = B | period = 3.626 | axis = 0.0440 | inclination = 164 | node = 225 | periastron = 2019.237 | eccentricity = 0.619 | periarg = 54 }} {{Starbox detail | component1 = A | age_myr = {{Val|23.7|1.4}}<ref name=mnras410_1_190/> | metal_fe = | mass = 5.413<ref name=Gratton2023/> | radius = 3.8<ref name=aaa367_521/> | gravity = 3.95<ref name=levenhagen2006/> | luminosity = 810.42<ref name=Anderson2012/> | temperature = 19,500<ref name=levenhagen2006/> | rotational_velocity = 147<ref name=uesugi_fukuda70/> | component2 = B | mass2 = 3.583<ref name=Gratton2023/> }} {{Starbox catalog | names = {{odlist | B=Rho Cen, ρ Cen | CD=−51°6455 | HD=105937 | HIP=59449 | HR=4638 | SAO=239737 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad=HD+105937 }} {{Starbox end}}

'''Rho Centauri''' is a [[binary star]]<ref name=Rizzuto2013/> system in the southern [[constellation]] of [[Centaurus]]. Its name is a [[Bayer designation]] that is [[Romanization of Greek|Latinized]] from ρ Centauri, and abbreviated Rho Cen or ρ Cen. This star is visible to the [[naked eye]] as a blue-white hued point of light with a combined [[apparent visual magnitude]] of +3.97.<ref name=Anderson2012/> The system is located approximately 276 [[light year]]s from the Sun based on [[stellar parallax|parallax]], and is drifting further away with a [[radial velocity]] of around +15 km/s.<ref name=Gontcharov2006/> It is a [[proper motion]] member of the Lower Centaurus–Crux sub-group in the [[Scorpius–Centaurus association|Scorpius–Centaurus]] [[Stellar association|OB association]], the nearest such association of co-moving massive stars to the Sun.<ref name=aaa216_1_44/>

The primary component of this system is a [[B-type main-sequence star]] with a [[stellar classification]] of B3 V.<ref name=aaa216_1_44/> It is about 24<ref name=mnras410_1_190/> million years old with a high rate of spin, showing a [[projected rotational velocity]] of 147 km/s.<ref name=uesugi_fukuda70/> It has 5.4<ref name=Gratton2023/> times the [[mass of the Sun]] and 3.8<ref name=aaa367_521/> times the [[Sun's radius]]. The star is radiating 810<ref name=Anderson2012/> times the [[luminosity of the Sun]] from its [[photosphere]] at an [[effective temperature]] of 19,500 K.<ref name=levenhagen2006/>

The secondary companion is 1.1 magnitudes fainter than the primary, with a [[projected separation]] of {{Val|5.68|ul=AU}} along a [[position angle]] of 19.72°, as of 2013.<ref name=Rizzuto2013/> It revolves around the primary star in 3.6 years, on an [[Orbital eccentricity|ecccentric]] orbit.<ref name=Mason2023/> The mass is estimated at 3.6 times that of the Sun, or 66% that of the primary.<ref name=Gratton2023/>

==References== <references> <ref name=GaiaDR3>{{cite DR3 | 6125166320994675456 | mode=cs2 | postscript=. }}</ref>

<ref name=Anderson2012>{{cite XHIP | 59449 | mode=cs2 | postscript=. }}</ref>

<ref name=Gontcharov2006>{{citation | last=Gontcharov | first=G. A. | title=Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system | journal=Astronomy Letters | volume=32| issue=11| pages=759–771| date=November 2006 | doi=10.1134/S1063773706110065 | bibcode=2006AstL...32..759G | arxiv=1606.08053 | s2cid=119231169 | postscript=. }}</ref>

<ref name=aaa367_521>{{citation | 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) - Third edition - Comments and statistics | journal=Astronomy and Astrophysics | display-authors=1 | volume=367 | pages=521–524 |date=February 2001 | issue=2 | doi=10.1051/0004-6361:20000451 | bibcode=2001A&A...367..521P | arxiv=astro-ph/0012289 | s2cid=425754 | postscript=. }}</ref>

<ref name=uesugi_fukuda70>{{citation | last1=Uesugi | first1=Akira | last2=Fukuda | first2=Ichiro | title=Catalogue of rotational velocities of the stars | journal=Contributions from the Institute of Astrophysics and Kwasan Observatory | date=1970 | publisher=University of Kyoto | bibcode=1970crvs.book.....U | postscript=. }}</ref>

<ref name=apjs15>{{citation | last1=Gutierrez-Moreno | first1=Adelina | last2=Moreno | first2=Hugo | title=A photometric investigation of the Scorpio-Centaurus association | journal=Astrophysical Journal Supplement | postscript=. | volume=15 | page=459 | date=June 1968 | bibcode=1968ApJS...15..459G | doi=10.1086/190168 | doi-access=free }}</ref>

<ref name=aaa216_1_44>{{citation | display-authors=1 | last1=de Geus | first1=E. J. | last2=de Zeeuw | first2=P. T. | last3=Lub | first3=J. | title=Physical parameters of stars in the Scorpio-Centaurus OB association | journal=Astronomy and Astrophysics | volume=216 | issue=1–2 | pages=44–61 | date=June 1989 | bibcode=1989A&A...216...44D }}</ref>

<ref name=mnras410_1_190>{{citation | display-authors=1 | last1=Tetzlaff | first1=N. | last2=Neuhäuser | first2=R. | last3=Hohle | first3=M. M. | title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=410 | issue=1 | pages=190–200 | date=January 2011 | bibcode=2011MNRAS.410..190T | arxiv=1007.4883 | doi=10.1111/j.1365-2966.2010.17434.x | doi-access=free | s2cid=118629873 }}</ref>

<ref name=SIMBAD>{{cite simbad | title=rho Cen | mode=cs2 | postscript=. | access-date=2019-10-10 }}</ref>

<ref name=levenhagen2006>{{citation | last1=Levenhagen | first1=R. S. | last2=Leister | first2=N. V. | title=Spectroscopic analysis of southern B and Be stars | journal=Monthly Notices of the Royal Astronomical Society | volume=371 | pages=252–262 | year=2006 | issue=1 | bibcode=2006MNRAS.371..252L | arxiv=astro-ph/0606149 | doi=10.1111/j.1365-2966.2006.10655.x | doi-access=free | s2cid=16492030 | postscript=. }}</ref>

<ref name=Rizzuto2013>{{citation | title=Long-baseline interferometric multiplicity survey of the Sco-Cen OB association | display-authors=1 | last1=Rizzuto | first1=A. C. | last2=Ireland | first2=M. J. | last3=Robertson | first3=J. G. | last4=Kok | first4=Y. | last5=Tuthill | first5=P. G. | last6=Warrington | first6=B. A. | last7=Haubois | first7=X. | last8=Tango | first8=W. J. | last9=Norris | first9=B. | last10=ten Brummelaar | first10=T. | last11=Kraus | first11=A. L. | last12=Jacob | first12=A. | last13=Laliberte-Houdeville | first13=C. | journal=Monthly Notices of the Royal Astronomical Society | volume=436 | issue=2 | pages=1694–1707 | date=December 2013 | doi=10.1093/mnras/stt1690 | doi-access=free | bibcode=2013MNRAS.436.1694R | postscript=. |arxiv = 1309.3811 }}</ref>

<ref name=Mason2023>{{citation | postscript=. | title=Speckle Interferometry at SOAR in 2022 | last1=Mason | first1=Brian D. | last2=Tokovinin | first2=Andrei | last3=Mendez | first3=Rene A. | last4=Costa | first4=Edgardo | display-authors=1 | journal=The Astronomical Journal | date=October 2023 | volume=166 | issue=4 | page=139 | doi=10.3847/1538-3881/acedaf | doi-access=free | bibcode=2023AJ....166..139M }}</ref>

<ref name="Gratton2023">{{citation | postscript=. | title=Multiples among B stars in the Scorpius-Centaurus association | display-authors=1 | last1=Gratton | first1=R. | last2=Squicciarini | first2=V. | last3=Nascimbeni | first3=V. | last4=Janson | first4=M. | last5=Reffert | first5=S. | last6=Meyer | first6=M. | last7=Delorme | first7=P. | last8=Mamajek | first8=E. E. | last9=Bonavita | first9=M. | last10=Desidera | first10=S. | last11=Mesa | first11=D. | last12=Rigliaco | first12=E. | last13=D’Orazi | first13=V. | last14=Vigan | first14=A. | last15=Lazzoni | first15=C. | last16=Chauvin | first16=G. | last17=Langlois | first17=M. | journal=Astronomy & Astrophysics | date=October 2023 | volume=678 | page=A93 | doi=10.1051/0004-6361/202346806 | doi-access=free | arxiv=2308.09962 | bibcode=2023A&A...678A..93G }} [https://vizier.cds.unistra.fr/viz-bin/VizieR-6?-out.form=%2bH&-source=J/A%2bA/678/A93&HIP=59449 Vizier catalog entry]</ref>

</references>

{{Stars of Centaurus|state=collapsed}}  [[Category:B-type main-sequence stars]] [[Category:Spectroscopic binaries]] [[Category:Lower Centaurus Crux]]  [[Category:Centaurus]] [[Category:Bayer objects|Centauri, Rho]] [[Category:Bright Star Catalogue objects|4638]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|105937]] [[Category:Hipparcos objects|059449]]