{{Short description|Brighter component of a wide double star system in the constellation Lupus}} {{Starbox begin | name = ζ 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=ζ Lupi |x=530|y=1110 }} | caption = Location of ζ Lupi (circled in red) }} {{Starbox observe | epoch = [[J2000.0]] | equinox = [[J2000.0]] ([[International Celestial Reference System|ICRS]]) | constell = [[Lupus (constellation)|Lupus]] | ra = {{RA|15|12|17.09595}}<ref name=vanLeeuwen2007/> | dec = {{DEC|−52|05|57.2919}}<ref name=vanLeeuwen2007/> | appmag_v = 3.41<ref name=Johnson1966/> {{nowrap|(3.50 + 6.74)}}<ref name=WDSC2014/> }} {{Starbox character | class = G7 III<ref name=Gray2006/> | b-v = +0.92<ref name=Johnson1966/> | u-b = +0.66<ref name=Johnson1966/> | r-i = | variable = }} {{Starbox astrometry | radial_v = {{Val|−10.0|0.6}}<ref name=deBruijne2012/> | prop_mo_ra = −112.92<ref name=vanLeeuwen2007/> | prop_mo_dec = −71.18<ref name=vanLeeuwen2007/> | parallax = 27.80 | p_error = 0.15 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = 0.65<ref name=Pizzolato2000/> }} {{Starbox detail | source = <ref name=ottoni/> | component1 = ζ Lup A | mass = {{val|2.56|0.10}} | radius = {{val|9.00|0.18}} | luminosity = {{val|49.9|1.7}} | temperature = {{val|5114|36|fmt=commas}} | gravity = {{val|2.930|0.094}} | metal_fe = {{val|0.022|0.024}} | rotational_velocity = | age_myr = }} {{Starbox catalog | names = [[Bayer designation|ζ Lup]], [[Durchmusterung|CD]]−51°8830, [[FK5]] 558, [[Gliese Catalogue of Nearby Stars|GJ]] 9512 A, [[Henry Draper Catalogue|HD]] 134505, [[Hipparcos Catalogue|HIP]] 74395, [[Harvard Revised catalogue|HR]] 5649, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 242304, [[Washington Double Star Catalog|WDS]] J15123-5206A<ref name=SIMBAD/> }} {{Starbox reference | Simbad = zet+Lup }} {{Starbox end}} '''ζ Lupi''' (Latinised as '''Zeta Lupi''') is the brighter component of a wide [[double star]] in the [[constellation]] [[Lupus (constellation)|Lupus]], consisting of an orange-hued primary and a fainter secondary with a golden-yellow hue.<ref name=Streicher2007/> It is visible to the naked eye with a combined [[apparent visual magnitude]] of 3.41.<ref name=Johnson1966/> Based upon an annual [[stellar parallax|parallax shift]] of 27.80<ref name=vanLeeuwen2007/> [[milliarcsecond|mas]] as seen from Earth, it is located 117.3 [[light-year]]s from the [[Sun]].
This is a probable [[binary star]] system.<ref name=Eggleton2008/> As of 2013, the pair had an [[angular separation]] of 71.20 [[arcsecond]]s along a [[position angle]] of 249°.<ref name=WDSC2014/> The primary, component A, is an [[stellar evolution|evolved]] [[G-type star|G-type]] [[giant star]] with a visual magnitude of 3.50<ref name=WDSC2014/> and a [[stellar classification]] of G7 III.<ref name=Gray2006/> This is a [[red clump]] star, indicating that it is generating energy through the [[thermonuclear fusion]] of helium in its [[stellar core|core region]].<ref name=laney2012/> It is 2.6 times more massive than the Sun and nine times larger. Zeta Lupi is 50 times more luminous than the Sun, emitting this energy from its [[photosphere]] at an [[effective temperature]] of 5114 K.<ref name=ottoni/>
The secondary, component B, has a visual magnitude of 6.74.<ref name=WDSC2014/>
==References== <references>
<ref name=ottoni>{{Cite journal |last1=Ottoni |first1=G. |last2=Udry |first2=S. |last3=Ségransan |first3=D. |last4=Buldgen |first4=G. |last5=Lovis |first5=C. |last6=Eggenberger |first6=P. |last7=Pezzotti |first7=C. |last8=Adibekyan |first8=V. |last9=Marmier |first9=M. |last10=Mayor |first10=M. |last11=Santos |first11=N. C. |last12=Sousa |first12=S. G. |last13=Lagarde |first13=N. |last14=Charbonnel |first14=C. |date=2022-01-01 |title=CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars |bibcode=2022A&A...657A..87O |journal=Astronomy and Astrophysics |volume=657 |pages=A87 |doi=10.1051/0004-6361/202040078 |issn=0004-6361|arxiv=2201.01528 }} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/A+A/657/A87&HD=134505 Zeta Lupi's database entry] at [[VizieR]].</ref>
<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=Pizzolato2000>{{citation | display-authors=1 | last1=Pizzolato | first1=N. | last2=Maggio | first2=A. | last3=Sciortino | first3=S. | title=Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases | journal=Astronomy and Astrophysics | volume=361 | pages=614–628 | date=September 2000 | bibcode=2000A&A...361..614P | postscript=. }}</ref>
<ref name=laney2012>{{cite journal | title=A new Large Magellanic Cloud K-band distance from precision measurements of nearby red clump stars | journal=Monthly Notices of the Royal Astronomical Society | display-authors=1 | last1=Laney | first1=C. D. | last2=Joner | first2=M. D. | last3=Pietrzyński | first3=G. | volume=419 | issue=2 | pages=1637 | year=2012 | doi=10.1111/j.1365-2966.2011.19826.x | doi-access=free | bibcode=2012MNRAS.419.1637L |arxiv = 1109.4800 | s2cid=117788450 }}</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=WDSC2014>{{citation | display-authors=1 | last1=Mason | first1=B. D. | last2=Wycoff | first2=G. L. | last3=Hartkopf | first3=W. I. | last4=Douglass | first4=G. G. | last5=Worley | first5=C. E. | title=The Washington Visual Double Star Catalog | year=2014 | bibcode=2001AJ....122.3466M | url=http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds | access-date=2015-07-22 | doi = 10.1086/323920 | volume=122 | journal=The Astronomical Journal | issue=6 | pages=3466–3471| doi-access=free}}</ref>
<ref name=Streicher2007>{{citation | title=Lupus: a wild animal | last1=Streicher | first1=M. | journal=Monthly Notes of the Astronomical Society of South Africa | volume=66 | issue=5 and 6 | pages=124–127 | date=June 2007 | bibcode=2007MNSSA..66..124S | 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=Johnson1966>{{citation | 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 | display-authors=1 | bibcode=1966CoLPL...4...99J | postscript=. }}</ref>
<ref name=Gray2006>{{citation | last1=Gray | first1=R. O. | last2=Corbally | first2=C. J. | last3=Garrison | first3=R. F. | last4=McFadden | first4=M. T. | last5=Bubar | first5=E. J. | last6=McGahee | first6=C. E. | last7=O'Donoghue | first7=A. A. | last8=Knox | first8=E. R. | title=Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample | display-authors=1 | journal=[[The Astronomical Journal]] | volume=132 | issue=1 | pages=161–170 | date=July 2006 | doi=10.1086/504637 | bibcode=2006AJ....132..161G | arxiv=astro-ph/0603770 | s2cid=119476992 | postscript=. }}</ref>
<ref name=SIMBAD>{{cite simbad | title=zet Lup | access-date=2017-03-03 }}</ref>
</references>
{{Stars of Lupus|state=collapsed}}
[[Category:G-type giants]] [[Category:Horizontal-branch stars]] [[Category:Double stars]] [[Category:Lupus (constellation)]] [[Category:Bayer objects|Lupi, Zeta]] [[Category:Durchmusterung objects|CD-51 08830]] [[Category:Henry Draper Catalogue objects|134505]] [[Category:Hipparcos objects|074395]] [[Category:Bright Star Catalogue objects|5649]]