{{Short description|Binary star system in the constellation Centaurus}} {{Starbox begin}} {{Starbox image | image = {{Location mark | image=Centaurus IAU.svg | float=center | width=300 | position=right | mark=Red circle.svg | mark_width=10 | mark_link=ψ Cen | x%=31| y%=38 }} | caption = Location of ψ Centauri (circled) }}{{Starbox observe | epoch = J2000.0 | constell = [[Centaurus]] | ra = {{RA|14|20|33.43}}<ref name="van Leeuwen2007"/> | dec = {{DEC|−37|53|07.1}}<ref name="van Leeuwen2007"/> | appmag_v = +4.05<ref name=Johnson1966/> }} {{Starbox character | class = A0 IV<ref name=Buscombe1962/> {{nowrap|(B9 and A2)}}<ref name=Bruntt2006/> | b-v = −0.03<ref name=Buscombe1962/> | u-b = −0.11<ref name=Buscombe1962/> | variable = [[Eclipsing binary|eclipsing]]<ref name=Bruntt2006/> }} {{Starbox astrometry | radial_v = {{Val|1.8|0.9}}<ref name=Gontcharov2006/> | prop_mo_ra = {{Val|-63.69|0.18}}<ref name="van Leeuwen2007"/> | prop_mo_dec = {{Val|-10.65|0.15}}<ref name="van Leeuwen2007"/> | parallax = 13.049 | p_error = 0.063 | parallax_footnote = <ref name=Gallenne2019/> | dist_pc = {{Val|76.64|0.37}} | dist_ly = {{Val|{{convert|76.64|pc|ly|disp=number}}|{{convert|0.37|pc|ly|disp=number}}}} | dist_footnote = <ref name=Gallenne2019/> | absmag_v = {{Val|−0.35|0.14}}<ref name=Gerbaldi1999/> }} {{Starbox orbit | reference = <ref name=Gallenne2019/> | period = | period_unitless = {{Val|38.8121|(2)|u=days|fmt=commas}} | axis = | axis_unitless = {{Val|0.3874|0.0017|ul=AU}} | eccentricity = {{Val|0.550|0.001|fmt=commas}} | inclination = {{Val|89.20|0.13}} | node = {{Val|115.79|0.10}} | periastron = | periarg = {{Val|19.45|0.27}} | periarg_primary = <!--Argument of periastron (in degrees), primary --> | k1 = {{Val|49.51|0.16}} | k2 = {{Val|80.48|0.33}} }} {{Starbox detail | source = <ref name=Gallenne2019/> | component1 = ψ Cen A | mass = {{Val|3.187|0.031}} | radius = {{Val|3.814|0.007}} | luminosity = {{Val|140|17|15}} | temperature = {{Val|10450|300|fmt=commas}} | gravity = {{Val|3.811|0.003}}<ref name=Mantegazza2010/> | metal_fe = +{{val|0.05|0.10}} | rotational_velocity = 123.7<ref name=Mantegazza2010/> | rotation = {{Val|1.49|0.26|u=days}}<ref name=Bruntt2006/> | age_myr = {{Val|280|10}} | component2 = ψ Cen B | mass2 = {{Val|1.961|0.015}} | radius2 = {{Val|1.896|0.004}} | luminosity2 = {{Val|17.5|2.6|2.2}} | temperature2 ={{Val|8800|300|fmt=commas}} | metal2_fe = +{{val|0.05|0.10}} | gravity2 = {{Val|4.206|0.007}}<ref name=Mantegazza2010/> | rotational_velocity2 = 126.9<ref name=Mantegazza2010/> | age_myr2 = {{Val|280|10}} }} {{Starbox catalog | names = {{odlist | B=ψ Cen | CD=−37°9336 | FK5=1373 | HD=125473 | HIP=70090 | HR=5367 | SAO=205453 | GC=19337 | CCDM=J14206-3753 | WDS=J14206-3753 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+125473 }} {{Starbox end}}
'''Psi Centauri''' is a [[binary star]]<ref name=Eggleton2008/> system in the southern [[constellation]] of [[Centaurus]]. Its name is a [[Bayer designation]] that is [[Romanization of Greek|Latinized]] from ψ Centauri, and abbreviated Psi Cen or ψ Cen. This system is visible to the [[naked eye]] as a point of light with a baseline [[apparent visual magnitude]] of +4.05.<ref name=Johnson1966/> The distance to this system is 250 [[light year]]s based on [[stellar parallax|parallax]].<ref name=Gallenne2019/> The [[radial velocity]] is poorly constrained, but it appears to be slowly drifting away from the Sun at the rate of +2 km/s.<ref name=Gontcharov2006/>
[[File:PsiCenLightCurve.png|thumb|left|A [[light curve]] for Psi Centauri, plotted from data published by Bruntt ''et al.'' (2006)<ref name=Bruntt2006/>]] This is a [[Detached binary|detached]] [[eclipsing binary]] system with the secondary eclipse being total.<ref name=Bruntt2006/> The pair are orbiting each other with a [[orbital period|period]] of 38.81 days and an [[orbital eccentricity|eccentricity]] of 0.55.<ref name=Gallenne2019/>The brightness of the system dips by 0.28 and 0.16 magnitude during the two eclipses per orbit.<ref name=Bruntt2006/> The system displays an [[infrared excess]] at a [[wavelength]] of 60 [[μm]], indicating the presence of a circumstellar [[debris disk]] with a temperature of 120 K, orbiting at a distance of 64 [[Astronomical Unit|AU]].<ref name=Rhee2007/>
The pair have a combined [[stellar classification]] of A0 IV,<ref name=Buscombe1962/> matching a white-hued [[stellar classification|A-type]] [[subgiant]].<ref name=Johnson1966/> The two components appear to be at different [[stellar evolution|evolutionary]] stages.<ref name=Bruntt2006/> Both have high rotation rates, with [[projected rotational velocity|projected rotational velocities]] over 120 km/s.<ref name=Mantegazza2010/> The primary has 3.814 times the [[Sun's radius]] while the secondary is 1.896 times.<ref name=Gallenne2019/> The primary showed evidence of [[Pulsating variable|pulsational behavior]] with 1.996 and 5.127 cycles per day,<ref name=Bruntt2006/> which suggests it is a [[slowly pulsating B star]].<ref name=Mantegazza2010/> But this remains unconfirmed as of 2017,<ref name=Liakos2017/> and the finding may instead be the result of instrumental error.<ref name=Mantegazza2010/>
==References== {{Reflist|colwidth=30em|refs=
<ref name=SIMBAD>{{cite simbad | mode=cs2 | title=psi Cen | access-date=2017-06-30 }}</ref>
<ref name=Gontcharov2006>{{citation | last1=Gontcharov | first1=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=Mantegazza2010>{{citation | title=Spectroscopic search for g-mode pulsations in ψ Centauri | display-authors=1 | last1=Mantegazza | first1=L. | last2=Rainer | first2=M. | last3=Antonello | first3=E. | journal=Astronomy and Astrophysics | postscript=. | volume=512 | id=A42 | pages=5 | date=March 2010 | doi=10.1051/0004-6361/200913013 | bibcode=2010A&A...512A..42M | doi-access=free }}</ref>
<ref name=Gallenne2019>{{Citation | title=The Araucaria project: High-precision orbital parallax and masses of eclipsing binaries from infrared interferometry | last=Gallenne | first=A. | last2=Pietrzyński | first2=G. | last3=Graczyk | first3=D. | last4=Pilecki | first4=B. | last5=Storm | first5=J. | last6=Nardetto | first6=N. | last7=Taormina | first7=M. | last8=Gieren | first8=W. | last9=Tkachenko | first9=A. | last10=Kervella | first10=P. | last11=Mérand | first11=A. | last12=Weber | first12=M. | display-authors=1 | journal=Astronomy & Astrophysics | volume=632 | pages=A31 | year=2019 | language=en-gb | bibcode=2019A&A...632A..31G | doi=10.1051/0004-6361/201935837 | issn=0004-6361 | postscript=.}}</ref>
<ref name=Bruntt2006>{{citation | title=Eclipsing binaries observed with the WIRE satellite. I. Discovery and photometric analysis of the new bright A0 IV eclipsing binary ψ Centauri | last1=Bruntt | first1=H. | last2=Southworth | first2=J. | last3=Torres | first3=G. | last4=Penny | first4=A. J. | last5=Clausen | first5=J. V. | last6=Buzasi | first6=D. L. | display-authors=1 | journal=Astronomy and Astrophysics | volume=456 | issue=2 | pages=651–658 | date=September 2006 | doi=10.1051/0004-6361:20065628 | arxiv=astro-ph/0606551 | bibcode=2006A&A...456..651B | s2cid=16701277 | postscript=. }}</ref>
<ref name=Liakos2017>{{citation | title=Catalogue and properties of δ Scuti stars in binaries | last1=Liakos | first1=Alexios | last2=Niarchos | first2=Panagiotis | journal=Monthly Notices of the Royal Astronomical Society | volume=465 | issue=1 | pages=1181–1200 | date=February 2017 | doi=10.1093/mnras/stw2756 | doi-access=free | arxiv=1611.00200 | bibcode=2017MNRAS.465.1181L | postscript=. }}</ref>
<ref name="van Leeuwen2007">{{citation | title=Validation of the new Hipparcos reduction | last=van Leeuwen | first=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }} [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=69851 Vizier catalog entry ] </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 | arxiv=0806.2878 | s2cid=14878976 | postscript=. }}</ref>
<ref name=Johnson1966>{{citation | display-authors=1 | last1=Johnson | first1=H. L. | last2=Iriarte | first2=B. | last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z. | title=UBVRIJKL photometry of the bright stars | journal=Communications of the Lunar and Planetary Laboratory | volume=4 | issue=99 | year=1966 | page=99 | bibcode=1966CoLPL...4...99J | postscript=. }}</ref>
<ref name=Rhee2007>{{citation | last1=Rhee | first1=Joseph H. | last2=Song | first2=Inseok | last3=Zuckerman | first3=B. | last4=McElwain | first4=Michael | display-authors=1 | journal=The Astrophysical Journal | title=Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs | volume=660 | issue=2 | pages=1556–1571 |date=May 2007 | doi=10.1086/509912 | bibcode=2007ApJ...660.1556R | arxiv=astro-ph/0609555 | s2cid=11879505 | postscript=. }}</ref>
<ref name=Buscombe1962>{{citation | last=Buscombe | first=W. | title=Spectral classification of Southern fundamental stars | journal=Mount Stromlo Observatory Mimeogram | volume=4 | year=1962 | page=1 | postscript=. | bibcode=1962MtSOM...4....1B }}</ref>
<ref name=Gerbaldi1999>{{citation | display-authors=1 | last1=Gerbaldi | first1=M. | last2=Faraggiana | first2=R. | last3=Burnage | first3=R. | last4=Delmas | first4=F. | last5=Gómez | first5=A. E. | last6=Grenier | first6=S. | title=Search for reference A0 dwarf stars: Masses and luminosities revisited with HIPPARCOS parallaxes | journal=Astronomy and Astrophysics Supplement | postscript=. | volume=137 | issue=2 | pages=273–292 |date=June 1999 | doi=10.1051/aas:1999248 | bibcode=1999A&AS..137..273G | doi-access=free }}</ref>
}}
{{Stars of Centaurus}} {{DEFAULTSORT:Psi Centauri}} <!-- Physical properties --> [[Category:A-type subgiants]] [[Category:Eclipsing binaries]] <!-- Constellation & catalogues --> [[Category:Centaurus]] [[Category:Bayer objects|Centauri, Psi]] [[Category:Bright Star Catalogue objects|5367]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|125473]] [[Category:Hipparcos objects|070090]]