{{short description|Star in the constellation Libra}} {{Starbox begin}} {{Starbox image | image = {{Location mark |image=Libra constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=κ Librae |x=280|y=525 }} | caption = Location of κ Librae (circled in red) }} {{Starbox observe | epoch = J2000 | constell = [[Libra (constellation)|Libra]]<ref name=Anderson2012/> | ra = {{RA|15|41|56.79858}}<ref name=vanLeeuwen2007/> | dec = {{DEC|−19|40|43.7745}}<ref name=vanLeeuwen2007/> | appmag_v = 4.72<ref name=Johnson1966/> }} {{Starbox character | class = K5&nbsp;III<ref name=houk1978/> | b-v = +1.58<ref name=Johnson1966/> | u-b = +1.94<ref name=Johnson1966/> | r-i = | variable = }} {{Starbox astrometry | radial_v = {{Val|−4.5|1.5}}<ref name=deBruijne2012/> | prop_mo_ra = −32.06<ref name=vanLeeuwen2007/> | prop_mo_dec = −103.15<ref name=vanLeeuwen2007/> | parallax = 10.57 | p_error = 1.40 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = −0.62<ref name=Anderson2012/> }} {{Starbox detail | source = | mass = 1.6<ref name=kaltenegger2021/> | radius = 38<ref name=tycho-gaia/> | luminosity = 388<ref name=dr2/> | temperature = 3,875<ref name=tycho-gaia/> | gravity = 1.35<ref name=kaltenegger2021/> | metal_fe = −0.39<ref name=kaltenegger2021/> | rotational_velocity = | age_myr = }} {{Starbox catalog | names = {{odlist | B=κ Lib | F=43 Lib | BD=−19°4188 | FK5=1413 | HD=139997 | HIP=76880 | HR=5838 | SAO=159442 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = kap+Lib }} {{Starbox end}} '''Kappa Librae''' is a [[star system]] in the [[zodiac]] [[constellation]] of [[Libra (constellation)|Libra]]. Its name is a [[Bayer designation]] that is [[Romanization of Greek|Latinized]] from {{nobr|'''κ Librae'''}}, and abbreviated {{nobr|Kappa Lib}} or {{nobr|κ Lib}}. Its [[apparent visual magnitude]] is 4.72,<ref name=Johnson1966/> so it can be seen with the naked eye. The annual [[stellar parallax|parallax shift]] of 10.57&nbsp;[[milliarcsecond|mas]]<ref name=vanLeeuwen2007/> indicates it is roughly 310&nbsp;[[light year]]s away. It is positioned 0.02 degrees south of the [[ecliptic]].

The star shows acceleration components in its [[proper motion]], indicating with high probability that it is an [[astrometric binary]].<ref name=Makarov2005/> The visible component is an [[stellar evolution|evolved]] [[K-type star|K-type]] [[giant star]] with a [[stellar classification]] of K5&nbsp;III.<ref name=houk1978/> It is a suspected [[variable star]] with a brightness that ranges between 4.70 and 4.75.<ref name=Samus2004/> Kappa Librae is 38 times larger than the Sun,<ref name=tycho-gaia/> and is radating 388 times the [[solar luminosity]]<ref name=dr2/> from its [[stellar atmosphere|outer atmosphere]] at an [[effective temperature]] of {{val|fmt=commas|3,875|ul=K}}.<ref name=tycho-gaia/>

In [[Chinese astronomy]], Kappa Librae is called 日, [[Pinyin]]: Rì, meaning ''Sun'', because this star is marking itself and stand alone in ''Sun'' asterism, [[Room (Chinese constellation)|Room]] mansion (see: [[Chinese constellations]]).<ref name="ridpathlibra">[http://www.ianridpath.com/startales/libra.htm#chinese Ian Ridpath's Startales - Libra the Scales]</ref>

==References== {{reflist|2|refs=

<ref name=dr2>{{cite Gaia DR2|6253982698110532608}}</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=Anderson2012>{{cite XHIP|76880}}</ref>

<ref name=kaltenegger2021>{{citation |bibcode=2021Natur.594..505K |title=Past, present and future stars that can see Earth as a transiting exoplanet |last1=Kaltenegger |first1=L. |last2=Faherty |first2=J. K. |journal=Nature |date=2021 |volume=594 |issue=7864 |pages=505–507 |doi=10.1038/s41586-021-03596-y |pmid=34163055 |arxiv=2107.07936 }}</ref>

<ref name=tycho-gaia>{{citation |last1=McDonald |first1=I. |last2=Zijlstra |first2=A. A. |last3=Watson |first3=R. A. |date=2017-10-01 |title=Fundamental parameters and infrared excesses of Tycho-Gaia stars |journal=Monthly Notices of the Royal Astronomical Society |volume=471 |pages=770–791 |doi=10.1093/mnras/stx1433 |doi-access=free |issn=0035-8711|arxiv=1706.02208 |bibcode=2017MNRAS.471..770M |postscript=.}} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/MNRAS/471/770&RAJ2000=235.486659 Kappa Librae's database entry] at [[VizieR]].</ref>

<ref name=Samus2004>{{citation | last1=Samus | first1=N. N. | last2=Durlevich | first2=O. V. | display-authors=etal | date=2004 | postscript=. | title=Combined General Catalogue of Variable Stars (GCVS4.2) | journal=Vizier Online Data Catalog | bibcode=2004yCat.2250....0S }}</ref>

<ref name=Makarov2005>{{citation | title=Statistical Constraints for Astrometric Binaries with Nonlinear Motion | last1=Makarov | first1=V. V. | last2=Kaplan | first2=G. H. | journal=The Astronomical Journal | postscript=. | volume=129 | issue=5 | pages=2420–2427 | date=May 2005 | doi=10.1086/429590 | bibcode=2005AJ....129.2420M | url=https://apps.dtic.mil/sti/pdfs/ADA433654.pdf| archive-url=https://web.archive.org/web/20170924050424/http://www.dtic.mil/get-tr-doc/pdf?AD=ADA433654| url-status=live| archive-date=September 24, 2017| doi-access=free }}</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=houk1978>{{citation | last1=Houk | first1=Nancy | last2=Smith-Moore | first2=M. | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=4 | publication-place=Ann Arbor | year=1978 | publisher=Dept. of Astronomy, University of Michigan | bibcode=1988mcts.book.....H | 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=SIMBAD>{{cite simbad | title=kap Lib | accessdate=2017-01-30 | postscript=. }}</ref>

}}

{{Stars of Libra|state=collapsed}}

<!-- Propeties --> [[Category:K-type giants]] [[Category:Suspected variables]] [[Category:Astrometric binaries]] <!-- Location/catalogues --> [[Category:Libra (constellation)]] [[Category:Bayer objects|Librae, Kappa]] [[Category:Durchmusterung objects|BD-19 4188]] [[Category:Bright Star Catalogue objects|5838]] [[Category:Flamsteed objects|Librae, 43]] [[Category:Henry Draper Catalogue objects|139997]] [[Category:Hipparcos objects|076880]]