{{Short description|Star in the constellation Centaurus}} {{Starbox begin | name = φ Centauri }} {{Starbox image | image = {{Location mark | image=Centaurus constellation map.svg | float=center | width=280 | position=right | mark=Red circle.svg | mark_width=10 | mark_link=φ Cen | x=407| y=440 }} | caption = Location of φ Centauri (circled) }} {{Starbox observe | epoch = J2000.0 | constell = [[Centaurus]]<ref name=Anderson2012/> | ra = {{RA|13|58|16.27}}<ref name="van Leeuwen2007"/> | dec = {{DEC|−42|06|02.7}}<ref name="van Leeuwen2007"/> | appmag_v = +3.745<ref name=Anderson2012/> }} {{Starbox character | class = B2 IV<ref name=mnras410_1_190/> | b-v = −0.222<ref name=Moreno1968/> | u-b = −0.851<ref name=Moreno1968/> | variable = }} {{Starbox astrometry | radial_v = {{Val|+5.3|1.5}}<ref name=Gontcharov2006/> | prop_mo_ra = {{Val|−22.77|0.15}}<ref name="van Leeuwen2007"/> | prop_mo_dec = {{Val|−20.13|0.12}} | pm_footnote = <ref name="van Leeuwen2007"/> | parallax = 6.21 | p_error = 0.17 | parallax_footnote = <ref name="van Leeuwen2007"/> | absmag_v = −2.20<ref name=Anderson2012/> }} {{Starbox detail | mass = {{val|8.5|0.3}}<ref name=mnras410_1_190/> | radius = {{val|4.19|0.35}}<ref name=aj129_3_1642/> | luminosity = 4,000<ref name=aaa216_1_44/> | temperature = {{val|21638|388|fmt=commas}}<ref name=aj129_3_1642/> | metal_fe = | gravity = {{val|4.08|0.07}}<ref name=aj129_3_1642/> | rotational_velocity = 79<ref name=Wolff2007/> | age_myr = {{val|18.0|3.2}}<ref name=mnras410_1_190/> }} {{Starbox catalog | names = {{odlist | B=φ Cen | CD=−41°8329 | HD=121743 | HIP=68245 | HR=5248 | SAO=224577 | GC=18874 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+121743 }} {{Starbox end}} '''Phi Centauri''' is a blue-white hued [[star]] in the southern [[constellation]] [[Centaurus]]. Its name is a [[Bayer designation]] that is [[Romanization of Greek|Latinized]] from φ Centauri, and abbreviated Phi Cen or φ Cen. This star is visible to the [[naked eye]] with an [[apparent visual magnitude]] of +3.7.<ref name=Anderson2012/> The annual [[stellar parallax|parallax shift]] is {{Val|6.21|ul=mas}}<ref name="van Leeuwen2007"/> as measured from Earth, which yields a distance estimate of around 530 [[light year]]s. It is moving further from the Sun with a [[radial velocity]] of +5 km/s.<ref name=Gontcharov2006/>
This is a [[B-type star|B-type]] [[subgiant star]] with a [[stellar classification]] of B2 IV.<ref name=mnras410_1_190/> It has no known companions, but does show radial velocity variations and higher order pulsations in the [[stellar spectrum|spectrum]].<ref name=Alecian2014/> The star is just 18<ref name=mnras410_1_190/> million years old with 8.5<ref name=mnras410_1_190/> times the [[mass of the Sun]] and has 4.2<ref name=aj129_3_1642/> times the [[Sun's radius]]. It is radiating around 4,000<ref name=aaa216_1_44/> times the [[Sun's luminosity]] from its [[photosphere]] at an [[effective temperature]] of about 21,638 K.<ref name=aj129_3_1642/>
This star is a [[proper motion]] member of the Upper Centaurus–Lupus sub-group in the [[Scorpius–Centaurus association|Scorpius–Centaurus]] [[Stellar association|OB association]], the nearest such co-moving association of massive stars to the Sun.<ref name=aaa216_1_44/>
==References== <references>
<ref name=SIMBAD>{{cite simbad | title=phi Cen | mode=cs2 | access-date=2026-01-03 }}</ref>
<ref name=aj129_3_1642>{{citation | last1=Fitzpatrick | first1=E. L. | last2=Massa | first2=D. | title=Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry | journal=The Astronomical Journal | volume=129 | issue=3 | pages=1642–1662 | date=March 2005 | doi=10.1086/427855 | bibcode=2005AJ....129.1642F | arxiv=astro-ph/0412542 | s2cid=119512018 | postscript=. }}</ref>
<ref name=Wolff2007>{{citation | last1=Wolff | first1=S. C. | last2=Strom | first2=S. E. | last3=Dror | first3=D. | last4=Venn | first4=K. | title=Rotational Velocities for B0-B3 Stars in Seven Young Clusters: Further Study of the Relationship between Rotation Speed and Density in Star-Forming Regions | journal=[[The Astronomical Journal]] | display-authors=1 | volume=133 | pages=1092–1103 | date=2007 | issue=3 | doi=10.1086/511002 | bibcode=2007AJ....133.1092W | arxiv=astro-ph/0702133 | s2cid=119074863 | postscript=. }}</ref>
<ref name=Moreno1968>{{citation | last1=Gutierrez-Moreno | first1=Adelina | last2=Moreno | first2=Hugo | title=A photometric investigation of the Scorpio-Centaurus association | journal=Astrophysical Journal Supplement | volume=15 | page=459 | date=June 1968 | postscript=. | bibcode=1968ApJS...15..459G | doi=10.1086/190168 | doi-access=free }}</ref>
<ref name=Alecian2014>{{citation | title=Discovery of new magnetic early-B stars within the MiMeS HARPSpol survey | display-authors=1 | last1=Alecian | first1=E. | last2=Kochukhov | first2=O. | last3=Petit | first3=V. | last4=Grunhut | first4=J. | last5=Landstreet | first5=J. | last6=Oksala | first6=M. E. | last7=Wade | first7=G. A. | last8=Hussain | first8=G. | last9=Neiner | first9=C. | last10=Bohlender | first11=D. | last11=MiMeS Collaboration | journal=Astronomy & Astrophysics | postscript=. | volume=567 | id=A28 | pages=19 | date=July 2014 | doi=10.1051/0004-6361/201323286 | bibcode=2014A&A...567A..28A | arxiv=1404.5508 | s2cid=119161720 }}</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=Anderson2012>{{cite XHIP | 68245 | mode=cs2 }}</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 | postscript=. }}</ref>
<ref name="van Leeuwen2007">{{citation | title=Validation of the new Hipparcos reduction | last=van Leeuwen | first=F. | postscript=. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | date=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | s2cid=18759600 }} [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=68011 Vizier catalog entry ]</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 | doi=10.1111/j.1365-2966.2010.17434.x | doi-access=free | bibcode=2011MNRAS.410..190T | arxiv=1007.4883 | s2cid=118629873 | postscript=. }}</ref> </references>
{{Stars of Centaurus}}
{{DEFAULTSORT:Phi Centauri}} <!-- Physical properties --> [[Category:B-type subgiants]] [[Category:Upper Centaurus Lupus]] <!-- Constellation & catalogues --> [[Category:Centaurus]] [[Category:Bayer objects|Centauri, Phi]] [[Category:Bright Star Catalogue objects|5248]] [[Category:Durchmusterung objects]] [[Category:Hipparcos objects|068245]] [[Category:Henry Draper Catalogue objects|121743]]