{{Short description|Star in the constellation Lupus}} {{DISPLAYTITLE:Psi<sup>2</sup> Lupi}} {{Starbox begin | name = Psi<sup>2</sup> Lupi }} {{Starbox image | image = {{Location mark |image=Lupus constellation map.svg|alt=|float=center|width=250 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=Psi2 Lupi |x=300|y=428 }} | caption = Location of ψ<sup>2</sup> Lupi (circled in red) }} {{Starbox observe | epoch = [[J2000.0]] | equinox = [[J2000.0]] ([[International Celestial Reference System|ICRS]]) | constell = [[Lupus (constellation)|Lupus]] | ra = {{RA|15|42|41.02206}}<ref name=vanLeeuwen2007/> | dec = {{DEC|−34|42|37.4617}}<ref name=vanLeeuwen2007/> | appmag_v = 4.75<ref name=GutierrezMoreno1968/> }} {{Starbox character | class = B5&nbsp;V<ref name=MolendaZakowicz2005/> | b-v = −0.146<ref name=GutierrezMoreno1968/> | u-b = −0.570<ref name=GutierrezMoreno1968/> | r-i = | variable = Microvariable<ref name=MolendaZakowicz2005/> }} {{Starbox astrometry | radial_v = {{Val|+3.9|2.8}}<ref name=deBruijne2012/> | prop_mo_ra = −21.37<ref name=vanLeeuwen2007/> | prop_mo_dec = −29.98<ref name=vanLeeuwen2007/> | parallax = 8.97 | p_error = 0.27 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = −1.44<ref name=GutierrezMoreno1968/> }} {{Starbox orbit | reference = <ref name=Pourbaix2004/> | period_unitless = 12.26&nbsp;d | axis = <!--Semimajor axis (in arcseconds)--> | axis_unitless = <!--Semimajor axis (no units provided by template)--> | eccentricity = 0.19 | inclination = <!--Inclination (in degrees)--> | node = <!--Longitude of node (in degrees)--> | periastron = {{nowrap|2438252.97 ± 10.0 JD}} | periarg = 82.8 | k1 = 63.3 | k2 = 66.4 }} {{Starbox detail | source = | mass = | radius = | luminosity = | temperature = 15,135<ref name=MolendaZakowicz2005/> | gravity = 4.29<ref name=MolendaZakowicz2005/> | metal_fe = | rotational_velocity = | age_myr = }} {{Starbox catalog | names = [[Bayer designation|ψ<sup>2</sup>&nbsp;Lup]], [[Flamsteed designation|4&nbsp;Lup]], [[Durchmusterung|CD]]−34°10494, [[Henry Draper Catalogue|HD]]&nbsp;140008, [[Hipparcos Catalogue|HIP]]&nbsp;76945, [[Harvard Revised catalogue|HR]]&nbsp;5839, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]]&nbsp;206889<ref name=SIMBAD/> }} {{Starbox reference | Simbad = psi02+Lup }} {{Starbox end}} '''Psi<sup>2</sup> Lupi''' ('''ψ<sup>2</sup> Lup''') is a [[triple star]]<ref name=Eggleton2008/> system in the [[constellation]] [[Lupus (constellation)|Lupus]]. It is visible to the naked eye with an [[apparent magnitude]] of 4.75.<ref name=GutierrezMoreno1968/> Based upon an annual [[stellar parallax|parallax shift]] of 8.97<ref name=vanLeeuwen2007/>&nbsp;[[milliarcsecond|mas]] as seen from Earth, it is located around 360&nbsp;[[light year]]s from the [[Sun]]. At that distance, the visual magnitude is diminished by an [[extinction (astronomy)|extinction factor]] of {{Val|0.016|0.009}} due to [[interstellar dust]]. This system is a member of the Upper Centaurus–Lupus subgroup of the [[Scorpius–Centaurus association]].<ref name=Chen2012/>

The inner pair of stars in this system form a double-lined [[spectroscopic binary]] with an [[orbital period]] of 12.26&nbsp;days and an [[orbital eccentricity|eccentricity]] of 0.19. The two components are described as similar in appearance.<ref name=Pourbaix2004/> They have the [[stellar spectrum|spectrum]] of a [[B-type main sequence star]] with a [[stellar classification]] of B5&nbsp;V.<ref name=MolendaZakowicz2005/> The luminosity has a micro-variability with a [[frequency]] of 0.94483 cycles per day and an [[amplitude]] of 0.0067 in magnitude.<ref name=MolendaZakowicz2005/> The third component is a magnitude 10 star at an [[angular separation]] of 0.51&nbsp;[[arc second]]s.<ref name=Eggleton2008/>

==See also== *[[Psi1 Lupi|ψ<sup>1</sup> Lupi]]

==References== <references>

<ref name=vanLeeuwen2007>{{citation | title=Validation of the new Hipparcos reduction | last1=van Leeuwen | first1=F. | 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 | postscript=. }}</ref>

<ref name=GutierrezMoreno1968>{{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=MolendaZakowicz2005>{{citation | title=New beta Cephei and SPB Stars Discovered in Hipparcos Photometry | last1=Molenda-Zakowicz | first1=J. | last2=Polubek | first2=G. | journal=Acta Astronomica | volume=55 | pages=375–388 | date=December 2005 | bibcode=2005AcA....55..375M | postscript=. }}</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=Chen2012>{{citation | title=A Spitzer MIPS Study of 2.5–2.0 M<sub>☉</sub> Stars in Scorpius–Centaurus | display-authors=1 | last1=Chen | first1=Christine H. | last2=Pecaut | first2=Mark | last3=Mamajek | first3=Eric E. | last4=Su | first4=Kate Y. L. | last5=Bitner | first5=Martin | journal=The Astrophysical Journal | volume=756 | issue=2 | id=133 | pages=24 | date=September 2012 | doi=10.1088/0004-637X/756/2/133 | bibcode=2012ApJ...756..133C | arxiv=1207.3415 | s2cid=119278056 | postscript=. }}</ref>

<ref name=deBruijne2012>{{citation | last1=de Bruijne | first1=J. H. J. | last2=Eilers | first2=A.-C. | title=Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project | journal=Astronomy & Astrophysics | volume=546 | id=A61 | pages=14 | date=October 2012 | doi=10.1051/0004-6361/201219219 | bibcode=2012A&A...546A..61D | arxiv=1208.3048 | s2cid=59451347 | postscript=. }}</ref>

<ref name=Pourbaix2004>{{citation | title=S<sub>B<sup>9</sup></sub>: The ninth catalogue of spectroscopic binary orbits | journal=Astronomy & Astrophysics |display-authors=5 | last1=Pourbaix | first1=D. | last2=Tokovinin | first2=A. A. | last3=Batten | first3=A. H. | last4=Fekel | first4=F. C. | last5=Hartkopf | first5=W. I. | last6=Levato | first6=H. | last7=Morrell | first7=N. I. | last8=Torres | first8=G. | last9=Udry | first9=S. | volume=424 | issue=2 | pages=727–732 | date=2004 | doi=10.1051/0004-6361:20041213 | bibcode=2004A&A...424..727P | arxiv=astro-ph/0406573 | s2cid=119387088 | postscript=. }}</ref>

<ref name=SIMBAD>{{cite simbad | title=psi02 Lup | accessdate=2017-03-10 | postscript=. }}</ref>

</references> {{Stars of Lupus|state=collapsed}}

[[Category:B-type main-sequence stars]] [[Category:Triple star systems]] [[Category:Lupus (constellation)]] [[Category:Bayer objects|Lupi, Psi2]] [[Category:Flamsteed objects|Lupi, 4]] [[Category:Henry Draper Catalogue objects|140008]] [[Category:Hipparcos objects|076945]] [[Category:Bright Star Catalogue objects|5839]] [[Category:Durchmusterung objects|CD-34 10494]] [[Category:Upper Centaurus Lupus]]