{{Short description|Multiple star system in the constellation Lupus}} {{Starbox begin | name=π 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=π Lupi |x=585|y=910 }} | caption = Location of π Lupi (circled in red) }} {{Starbox observe | epoch=J2000 | ra={{RA|15|05|07.08596}}<ref name="van Leeuwen2007"/> | dec={{DEC|−47|03|04.4976}}<ref name="van Leeuwen2007"/> | appmag_v=3.89<ref name=aass34_1/> | constell=[[Lupus (constellation)|Lupus]] }} {{Starbox character | class=B5V + B5IV<ref name="Nitschelm2004"/> | b-v=−0.14<ref name=aass34_1/> | u-b=−0.59<ref name=aass34_1/> | variable= }} {{Starbox astrometry | radial_v=+4.50<ref name=an328_9_889/> | prop_mo_ra=−22.98<ref name="van Leeuwen2007"/> | prop_mo_dec=−22.81<ref name="van Leeuwen2007"/> | parallax=7.36 | p_error=0.55 | parallax_footnote=<ref name="van Leeuwen2007"/> | absmag_v= }} {{Starbox detail | component1 = A | mass = 4.5<ref name = Gullikson2016/> | radius= | luminosity= | temperature = 16,000<ref name = Gullikson2016/> | metal= | gravity = 4.5<ref name = Gullikson2016/> | rotational_velocity = 10<ref name = Gullikson2016/> | component2 = B | mass2 = 4.7<ref name = Gullikson2016/> | radius2 = | luminosity2 = | temperature2 = 14,000<ref name = Gullikson2016/> | metal2 = | gravity2 = | rotational_velocity2 = 10<ref name = Gullikson2016/> | age_myr2 = 14<ref name = Gullikson2016/> }} {{Starbox catalog | names=[[Durchmusterung|CD]]−46°9773, [[Hipparcos catalogue|HIP]] 73807, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 225426 | component1 = π Lupi A | names1 = [[Henry Draper Catalogue|HD]] 133242, [[Bright Star Catalogue|HR]] 5605 | component2 = π Lupi B | names2 = HD 133243, HR 5606 }} {{Starbox reference | Simbad=pi+Lup | Simbad2=pi+Lup+A|sn2=A | Simbad3=pi+Lup+B|sn3=B }} {{Starbox end}}
'''π Lupi''' (Latinised to Pi Lupi) is a multiple star system in the southern constellation [[Lupus (constellation)|Lupus]]. Two components form a wide binary pair with an orbital period of 517 years and a [[semimajor axis]] of 1.59″. They belong to the Upper Centaurus Lupus component of the [[Scorpius–Centaurus association|Sco–Cen complex]].<ref name="Nitschelm2004"/>
[[File:PiLupLightCurve.png|thumb|left|250px|A [[light curve]] for Pi Lupi, adapted from Sharma ''et al.'' (2022)<ref name=Sharma/>]]
At least one of the components is a [[spectroscopic binary]] and produces eclipses 15.5 days apart, making it an [[eclipsing binary]]. There are also other brightness variations with a period of 16 hours that are likely to be pulsations of the [[Slowly pulsating B-type star]]. The eclipses are shallow, with the brightness dropping by only 1% or about 0.01 magnitudes. The amplitude of the pulsations is even smaller.<ref name=Sharma/>
π Lupi A (HR 5605, HD 133242) has been classified as a spectroscopic binary by at least two studies,<ref name=buscombe1975/><ref name=chini2012/> but both components may be spectroscopic binaries.<ref name=wds/> {{clear left}} ==References== <references>
<ref name=buscombe1975>{{citation |bibcode=1975Ap&SS..37..197B |title=Absorption Line Profiles and Rotational Velocities for 59 Stars |last1=Buscombe |first1=W. |last2=Stoeckley |first2=T. R. |journal=Astrophysics and Space Science |year=1975 |volume=37 |issue=1 |page=197 |doi=10.1007/BF00646073 |s2cid=122985118 }}</ref>
<ref name=chini2012>{{citation |bibcode=2012MNRAS.424.1925C |title=A spectroscopic survey on the multiplicity of high-mass stars |last1=Chini |first1=R. |last2=Hoffmeister |first2=V. H. |last3=Nasseri |first3=A. |last4=Stahl |first4=O. |last5=Zinnecker |first5=H. |journal=Monthly Notices of the Royal Astronomical Society |year=2012 |volume=424 |issue=3 |page=1925 |doi=10.1111/j.1365-2966.2012.21317.x |doi-access=free |arxiv=1205.5238 |s2cid=119120749 }}</ref>
<ref name=wds>{{citation | display-authors=1 | author=Mason, Brian D. | author2=Wycoff, Gary L. | author3=Hartkopf, William I. | author4=Douglass, Geoffrey G. | author5=Worley, Charles E. | title=The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog | journal=The Astronomical Journal | volume=122 | issue=6 | pages=3466–3471 | date=December 2001 | doi=10.1086/323920 | bibcode=2001AJ....122.3466M | doi-access=free }}</ref>
<ref name=Sharma>{{citation|doi=10.1093/mnras/stac1816 |title=Pulsating B stars in the Scorpius–Centaurus Association with TESS |year=2022 |last1=Sharma |first1=Awshesh N. |last2=Bedding |first2=Timothy R. |last3=Saio |first3=Hideyuki |last4=White |first4=Timothy R. |journal=Monthly Notices of the Royal Astronomical Society |volume=515 |issue=1 |pages=828–840 |doi-access=free |arxiv=2203.02582 | bibcode=2022MNRAS.515..828S}}</ref>
<ref name = Gullikson2016>{{citation | last1 = Gullikson | first1 = Kevin | last2 = Kraus | first2 = Adam | last3 = Dodson-Robinson | first3 = Sarah | title = The Close Companion Mass-ratio Distribution of Intermediate-mass Stars | journal = The Astronomical Journal | date = 25 July 2016 | volume = 152 | issue = 2 | page = 40 | eissn = 1538-3881 | doi = 10.3847/0004-6256/152/2/40 | bibcode = 2016AJ....152...40G | arxiv = 1604.06456 | doi-access = free}}</ref>
<ref name="van Leeuwen2007">{{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 }}[http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=114184 Vizier catalog entry ] {{Webarchive|url=https://web.archive.org/web/20200901074941/http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I%2F311%2Fhip2&recno=114184 |date=2020-09-01 }}</ref>
<ref name=an328_9_889>{{citation | display-authors=1 | last1=Kharchenko | first1=N. V. | last2=Scholz | first2=R.-D. | last3=Piskunov | first3=A. E. | last4=Röser | first4=S. | last5=Schilbach | first5=E. | title=Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations | journal=Astronomische Nachrichten | volume=328 | issue=9 | pages=889–896 | date=2007 | doi=10.1002/asna.200710776 | bibcode=2007AN....328..889K | arxiv = 0705.0878 | s2cid=119323941 }}</ref>
<ref name=aass34_1>{{citation | last1=Nicolet | first1=B. | date=1978 | title=Photoelectric photometric Catalogue of homogeneous measurements in the UBV System | journal=Astronomy and Astrophysics Supplement Series | volume=34 | pages=1–49 | bibcode=1978A&AS...34....1N }}</ref>
<ref name="Nitschelm2004">{{citation | last1=Nitschelm | first1=C. | title=Discovery and confirmation of some double-lined spectroscopic binaries in the Sco-Cen Complex | work=Spectroscopically and Spatially Resolving the Components of the Close Binary Stars, Proceedings of the Workshop held 20–24 October 2003 in Dubrovnik, Croatia. | editor1-first=R. W. | editor1-last=Hilditch | editor2-first=H. | editor2-last=Hensberge | editor3-first=K. | editor3-last=Pavlovski | series=ASP Conference Series | volume=318 | publisher=[[Astronomical Society of the Pacific]] | pages=291–293 | date=December 2004 | bibcode=2004ASPC..318..291N }}</ref>
</references>
{{Stars of Lupus}}
[[Category:Lupus (constellation)]] [[Category:Bayer objects|Lupi, Pi]] [[Category:Henry Draper Catalogue objects|133242/3]] [[Category:Eclipsing binaries]] [[Category:Bright Star Catalogue objects|5605 6]] [[Category:Hipparcos objects|073807]] [[Category:Durchmusterung objects|CD-46 09773]] [[Category:B-type main-sequence stars]] [[Category:B-type subgiants]] [[Category:Upper Centaurus Lupus]]