{{Short description|Binary star system in the constellation Lupus}} {{Starbox begin}} {{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=ο Lupi |x=688|y=780 }} | caption = Location of ο Lupi (circled in red) }} {{Starbox observe | epoch = [[J2000.0]] | equinox = [[J2000.0]] ([[International Celestial Reference System|ICRS]]) | constell = [[Lupus (constellation)|Lupus]] | ra = {{RA|14|51|38.30289}}<ref name=vanLeeuwen2007/> | dec = {{DEC|−43|34|31.2965}}<ref name=vanLeeuwen2007/> | appmag_v = 4.323<ref name=Cousins1973/> {{nowrap|(4.84 + 5.27)}}<ref name=Eggleton2008/> }} {{Starbox character | class = B5 IV<ref name=Eggleton2008/> | b-v = −0.159<ref name=Cousins1973/> | u-b = −0.620<ref name=Cousins1973/> | r-i = | variable = }} {{Starbox astrometry | radial_v = {{Val|+7.30|0.74}}<ref name=deBruijne2012/> | prop_mo_ra = −25.20<ref name=vanLeeuwen2007/> | prop_mo_dec = −27.13<ref name=vanLeeuwen2007/> | parallax = 8.07 | p_error = 0.59 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = {{Val|−1.2|0.3}}<ref name=Petit2013/> }} {{Starbox detail | source = | mass = {{Val|5.7|0.2}}<ref name=Petit2013/> | radius = 3.5<ref name=Petit2013/> | luminosity = 1,260<ref name=Petit2013/> | temperature = 18,000<ref name=Alecian2011/> | gravity = {{Val|4.1|0.1}}<ref name=Petit2013/> | metal_fe = | rotational_velocity = 25<ref name=Alecian2011/> | age_myr = }} {{Starbox catalog | names = [[Bayer designation|ο Lup]], [[Durchmusterung|CD]]−43°9391, [[Henry Draper Catalogue|HD]] 130807, [[Hipparcos Catalogue|HIP]] 72683, [[Harvard Revised catalogue|HR]] 5528, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 225248<ref name=SIMBAD/> }} {{Starbox reference | Simbad = omi+Lup }} {{Starbox end}} '''Omicron Lupi''' ('''ο Lup''') is a [[binary star]]<ref name=Eggleton2008/> in the [[Southern celestial hemisphere|southern]] [[constellation]] of [[Lupus (constellation)|Lupus]]. It is a visible to the naked eye with a combined [[apparent visual magnitude]] of 4.323.<ref name=Cousins1973/> Based upon an annual [[stellar parallax|parallax shift]] of 8.07 [[milliarcsecond|mas]] as seen from Earth,<ref name=vanLeeuwen2007/> it is located around 400 [[light-year]]s from the [[Sun]], give or take 30 light-years. At that distance, the visual magnitude of the system is diminished by an [[extinction (astronomy)|extinction factor]] of {{Val|0.13|0.01}} due to [[interstellar dust]].<ref name=Petit2013/> It is a member of the Upper Centaurus–Lupus<ref name=Chen2012/> subgroup of the nearby [[Scorpius–Centaurus association]].<ref name=Alecian2011/>
This is a [[visual binary]] star system with the components having an [[angular separation]] of 0.1 [[arcsecond]].<ref name=Chen2012/> The primary, component A, is a magnitude 4.84 [[B-type star|B-type]] [[subgiant]] star with a [[stellar classification]] of B5 V.<ref name=Eggleton2008/> It displays [[radial velocity]] variations indicating it has an unseen second companion orbiting at a separation of at least 17 [[astronomical unit|AU]] with a period of 27 years or more.<ref name=Alecian2011/> The spectrum of the primary displays a [[Zeeman effect]] indicating a [[stellar magnetic field|magnetic field]] with a strength ranging from −94 to 677 [[Gauss (unit)|G]].<ref name=Alecian2011/> The visible companion, component B, has a visual magnitude of 5.27.<ref name=Eggleton2008/>
==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=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=Petit2013>{{citation | title=A magnetic confinement versus rotation classification of massive-star magnetospheres | display-authors=1 | last1=Petit | first1=V. | last2=Owocki | first2=S. P. | last3=Wade | first3=G. A. | last4=Cohen | first4=D. H. | last5=Sundqvist | first5=J. O. | last6=Gagné | first6=M. | last7=Maíz Apellániz | first7=J. | last8=Oksala | first8=M. E. | last9=Bohlender | first9=D. A. | last10=Rivinius | first10=T. | last11=Henrichs | first11=H. F. | last12=Alecian | first12=E. | last13=Townsend | first13=R. H. D. | last14=ud-Doula | first14=A. | last15=MiMeS Collaboration | journal=Monthly Notices of the Royal Astronomical Society | volume=429 | issue=1 | pages=398–422 | date=February 2013 | doi=10.1093/mnras/sts344 | doi-access=free | bibcode=2013MNRAS.429..398P | arxiv=1211.0282 | postscript=. | url=https://pure.uva.nl/ws/files/1746728/147519_A_magnetic_confinement.pdf}}</ref>
<ref name=Alecian2011>{{citation | title=First HARPSpol discoveries of magnetic fields in massive stars | display-authors=1 | last1=Alecian | first1=E. | last2=Kochukhov | first2=O. | last3=Neiner | first3=C. | last4=Wade | first4=G. A. | last5=de Batz | first5=B. | last6=Henrichs | first6=H. | last7=Grunhut | first7=J. H. | last8=Bouret | first8=J.-C. | last9=Briquet | first9=M. | last10=Gagne | first10=M. | last11=Naze | first11=Y. | last12=Oksala | first12=M. E. | last13=Rivinius | first13=T. | last14=Townsend | first14=R. H. D. | last15=Walborn | first15=N. R. | last16=Weiss | first16=W. | last17=Mimes Collaboration | journal=Astronomy & Astrophysics | postscript=. | arxiv=1111.3433 | volume=536 | id=L6 | pages=4 | date=December 2011 | doi=10.1051/0004-6361/201118354 | bibcode=2011A&A...536L...6A | s2cid=51173988 }}</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=Cousins1973>{{citation | last1=Cousins | first1=A. W. J. | title=Revised zero points and UBV photometry of stars in the Harvard E and F regions | journal= Memoirs of the Royal Astronomical Society | volume=77 | pages=223–236 | year=1973 | bibcode=1973MmRAS..77..223C | postscript=. }}</ref>
<ref name=SIMBAD>{{cite simbad | title=omi Lup | access-date=2017-03-10 }}</ref>
</references>
{{Stars of Lupus|state=collapsed}}
[[Category:B-type subgiants]] [[Category:Binary stars]] [[Category:Lupus (constellation)]] [[Category:Bayer objects|Lupi, Omicron]] [[Category:Hipparcos objects|072683]] [[Category:Henry Draper Catalogue objects|130807]] [[Category:Bright Star Catalogue objects|5528]] [[Category:Durchmusterung objects|CD-43 09391]] [[Category:Upper Centaurus Lupus]]