{{Short description|Binary star 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=κ Lupi |x=540|y=970 }} | caption = Location of κ Lupi (circled in red) }} {{Starbox observe 2s | epoch = [[J2000.0]] | equinox = [[International Celestial Reference System|ICRS]] | constell = [[Lupus (constellation)|Lupus]]<ref name=XHIP-k1/><ref name=XHIP-k2/> | component1 = κ<sup>1</sup> Lup | ra1 = {{RA|15|11|56.07286}}<ref name=vanLeeuwen2007/> | dec1 = {{DEC|−48|44|16.1692}}<ref name=vanLeeuwen2007/> | appmag_v1 =3.86<ref name=Mermilliod1986/> | component2 = κ<sup>2</sup> Lup | ra2 = {{RA|15|11|57.67537}}<ref name=GaiaDR3-k2/> | dec2 = {{DEC|−48|44|37.2684}}<ref name=GaiaDR3-k2/> | appmag_v2 = 5.70<ref name=XHIP-k2/> }} {{Starbox character | component1 = κ<sup>1</sup> Lup | class = B9.5 Vne<ref name=levenhagen2006/> | b-v = −0.05<ref name=Mermilliod1986/> | u-b = −0.08<ref name=Mermilliod1986/> | r-i = | variable = | component2 = κ<sup>2</sup> Lup | type2 = [[main sequence]]<ref name=GaiaDR3-k2/> | class2 = A3/5V<ref name=houk1978/> | b-v2 = {{Val|+0.144|0.008}}<ref name=XHIP-k2/> | u-b2 = | variable2 = }} {{Starbox astrometry | component1 = κ<sup>1</sup> Lup | radial_v = {{Val|−6.6|2.9}}<ref name=deBruijne2012/> | prop_mo_ra = −96.50<ref name=vanLeeuwen2007/> | prop_mo_dec = −49.86<ref name=vanLeeuwen2007/> | parallax = 18.12 | p_error = 0.47 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = | component2 = κ<sup>2</sup> Lup | radial_v2 = {{Val|+0.0|3.7}}<ref name=Kharchenko2007/> | prop_mo_ra2 = −98.497 | prop_mo_dec2 = −43.645 | pm_footnote2 = <ref name=GaiaDR3-k2/> | parallax2 = 17.906 | p_error2 = 0.0587 | parallax_footnote2 = <ref name=GaiaDR3-k2/> | absmag_v2 = +1.84<ref name=ap1999/> }} {{Starbox detail | component1 = κ<sup>1</sup> Lup | source = | mass = {{Val|2.89|0.03}}<ref name=Zorec2012/> | radius = 3.0<ref name=tic/> | luminosity = 90<ref name=tic/> | temperature = 10,280<ref name=tic/> | gravity = {{Val|3.99|0.14}}<ref name=David2015/> | metal_fe = | rotational_velocity = {{Val|191|16}}<ref name=Zorec2012/> | age_myr = 121<ref name=David2015/> | component2 = κ<sup>2</sup> Lup | mass2 = 2.0<ref name=tic/> | radius2 = 1.8<ref name=tic/> | metal2_fe = −0.01<ref name=Netopil2017/> | rotation2 = | gravity2 = 4.26<ref name=tic/> | age_myr2 = 653<ref name=GaiaDR3-k2/> | luminosity2 = 13<ref name=tic/> | temperature2= 8,255<ref name=tic/> | rotational_velocity2= {{Val|160.4|1.0}}<ref name=Diaz2011/> }} {{Starbox catalog | component1 = κ<sup>1</sup> Lup | names1 = [[Durchmusterung|CD]]−48°9704, [[FK5]] 1398, [[Henry Draper Catalogue|HD]] 134481, [[Hipparcos Catalogue|HIP]] 74376, [[Harvard Revised catalogue|HR]] 5646, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 225525<ref name=SIMBAD-k1/> | component2 = κ<sup>2</sup> Lup | names2 = {{odlist | CD=−48°9705 | HD=134482 | HIP=74380 | HR=5647 | SAO=225526 }}<ref name=SIMBAD-k2/> }} {{Starbox reference | Simbad = kap01+Lup |sn=κ<sup>1</sup> Lup }} {{Starbox reference|no_heading=y | Simbad = kap02+Lup |sn=κ<sup>2</sup> Lup }} {{Starbox end}} '''Kappa Lupi''' is a [[binary star]]<ref name=Eggleton2008/> in the constellation of Lupus. With a combined [[apparent magnitude]] of 3.70,<ref name=Ducati2002/> it is visible to the [[naked eye]]. The average distance to this system, based on [[parallax]] measurements, is 180 [[light-year]]s.
The stars in the system are separated by an [[angular separation]] of {{Val|26.44|ul=arcsecond}}.<ref name=Eggleton2008/> At their distance, this corresponds to a [[projected separation]] of 1,450 [[astronomical unit]]s.<ref>26.44"{{*}}55 pc = 1,450 AU.</ref> They are members of the [[Hyades Stream]], which is a [[moving group]] that is coincident with the [[proper motion]]s of the [[Hyades (star cluster)|Hyades]] cluster.<ref name=eggen1996/>
The primary, Kappa<sup>1</sup> Lupi, has an [[apparent magnitude]] of 3.86.<ref name=Mermilliod1986/> It is a [[B-type main sequence star]] with a [[stellar classification]] of B9.5 Vne.<ref name=levenhagen2006/> The 'n' suffix indicates the [[spectrum]] shows "nebulous" [[absorption line]]s due to rapid rotation, while the 'e' means this is a [[Be star]] that displays [[Balmer series]] emission lines. With an estimated age of 195 million years,<ref name=levenhagen2006/> it is about 75% of the way through its life span on the [[main sequence]].<ref name=Zorec2012/> The star is rotating with a [[projected rotational velocity]] of 191 km/s.<ref name=Zorec2012/> This rate of spin is giving the star an [[Oblate spheroid|oblate]] shape with an [[equatorial bulge]] that is an estimated 9% larger than the polar radius.<ref name=belle2012/>
The secondary, Kappa<sup>2</sup> Lupi, has an [[apparent magnitude]] of 5.70.<ref name=XHIP-k2/> It is an [[A-type main-sequence star]] with a [[stellar classification]] of A3/5V.<ref name=houk1978/> The star has a high rotation rate, showing a [[projected rotational velocity]] of 160 km/s.<ref name=Diaz2011/> It is 2.0 times more massive and 1.8 times larger than the Sun, with 13 times the Sun's luminosity and an [[effective temperature]] of 8,255 K.<ref name=tic/>
In [[Chinese astronomy]], Kappa<sup>1</sup> Lupi is called 騎陣將軍, [[Pinyin]]: Qízhènjiāngjūn, meaning ''Chariots and Cavalry General'', because this star is marking itself and stand alone in ''Chariots and Cavalry General'' asterism, [[Root (Chinese constellation)|Root]] mansion (see : [[Chinese constellation]]).<ref>{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0606/ap060629.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 29 日] {{Webarchive|url=https://web.archive.org/web/20210605100121/http://aeea.nmns.edu.tw/2006/0606/ap060629.html |date=2021-06-05 }}</ref>
==References== <references>
<ref name=GaiaDR3-k2>{{cite Gaia DR3|5902489102985502208}}</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=eggen1996>{{citation | last1=Eggen | first1=Olin J. | title=The Stellar Content of Star Stream I | journal=Astronomical Journal | volume=111 | pages=1615 | year=1996 | bibcode=1996AJ....111.1615E | doi=10.1086/117901 }}</ref>
<ref name=Ducati2002>{{Cite journal |last=Ducati |first=J. R. |year=2002 |title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system. |bibcode=2002yCat.2237....0D |journal=VizieR Online Data Catalog |language=en |volume=2237}}</ref>
<ref name=XHIP-k1>{{cite XHIP|74376}}</ref>
<ref name=XHIP-k2>{{cite XHIP|74380}}</ref>
<ref name=tic>{{cite journal |bibcode=2019AJ....158..138S |title=The Revised TESS Input Catalog and Candidate Target List |last1=Stassun |first1=Keivan G. |last2=Oelkers |first2=Ryan J. |last3=Paegert |first3=Martin |last4=Torres |first4=Guillermo |last5=Pepper |first5=Joshua |last6=De Lee |first6=Nathan |last7=Collins |first7=Kevin |last8=Latham |first8=David W. |last9=Muirhead |first9=Philip S. |last10=Chittidi |first10=Jay |last11=Rojas-Ayala |first11=Bárbara |last12=Fleming |first12=Scott W. |last13=Rose |first13=Mark E. |last14=Tenenbaum |first14=Peter |last15=Ting |first15=Eric B. |last16=Kane |first16=Stephen R. |last17=Barclay |first17=Thomas |last18=Bean |first18=Jacob L. |last19=Brassuer |first19=C. E. |last20=Charbonneau |first20=David |last21=Ge |first21=Jian |last22=Lissauer |first22=Jack J. |last23=Mann |first23=Andrew W. |last24=McLean |first24=Brian |last25=Mullally |first25=Susan |last26=Narita |first26=Norio |last27=Plavchan |first27=Peter |last28=Ricker |first28=George R. |last29=Sasselov |first29=Dimitar |last30=Seager |first30=S. |journal=The Astronomical Journal |date=2019 |volume=158 |issue=4 |page=138 |doi=10.3847/1538-3881/ab3467 |doi-access=free |arxiv=1905.10694 |display-authors=1 }}</ref>
<ref name=David2015>{{citation | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146 | arxiv=1501.03154 | s2cid=33401607 | postscript=. }}</ref>
<ref name=belle2012>{{citation | title=Interferometric observations of rapidly rotating stars | last1=Belle | first1=G. T. | journal=The Astronomy and Astrophysics Review | volume=20 | pages=51 | year=2012 | issue=1 | doi=10.1007/s00159-012-0051-2 | bibcode=2012A&ARv..20...51V | arxiv=1204.2572 | s2cid=119273474 | 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=Zorec2012>{{citation | last1=Zorec | first1=J. | last2=Royer | first2=F. | title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities | journal=Astronomy & Astrophysics | volume=537 | page=A120 | date=January 2012 | doi=10.1051/0004-6361/201117691 | bibcode=2012A&A...537A.120Z | arxiv=1201.2052 | s2cid=55586789 | postscript=. }}</ref>
<ref name=levenhagen2006>{{citation | last1=Levenhagen | first1=R. S. | last2=Leister | first2=N. V. | title=Spectroscopic analysis of southern B and Be stars | journal=Monthly Notices of the Royal Astronomical Society | volume=371 | pages=252–262 | year=2006 | issue=1 | bibcode=2006MNRAS.371..252L | doi=10.1111/j.1365-2966.2006.10655.x | doi-access=free | arxiv=astro-ph/0606149 | s2cid=16492030 | postscript=. }}</ref>
<ref name=Mermilliod1986>{{citation | last1=Mermilliod | first1=J.-C. | title=Compilation of Eggen's UBV data, transformed to UBV (unpublished) | journal=Catalogue of Eggen's UBV Data | year=1986 | publisher=[[SIMBAD]] | bibcode=1986EgUBV........0M | postscript=. }}</ref>
<ref name=SIMBAD-k1>{{cite simbad | title=kap01 Lup | access-date=2017-03-07 | postscript=. }}</ref>
<ref name=SIMBAD-k2>{{cite simbad | title=kap02 lup | accessdate=2019-09-14 }}</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=Diaz2011>{{citation | last1=Díaz | first1=C. G. | last2=González | first2=J. F. | last3=Levato | first3=H. | last4=Grosso | first4=M. | title=Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum | display-authors=1 | journal=Astronomy & Astrophysics | volume=531 | page=A143 |date=July 2011 | doi=10.1051/0004-6361/201016386 | bibcode=2011A&A...531A.143D | arxiv=1012.4858 | s2cid=119286673 | postscript=. }}</ref>
<ref name=Netopil2017>{{citation | title=Metallicity calibrations for dwarf stars and giants in the Geneva photometric system | last1=Netopil | first1=Martin | journal=Monthly Notices of the Royal Astronomical Society | volume=469 | issue=3 | pages=3042–3055 | date=August 2017 | doi=10.1093/mnras/stx1077 | doi-access=free | arxiv=1705.00883 | bibcode=2017MNRAS.469.3042N | s2cid=119034918 | postscript=. }}</ref>
<ref name=ap1999>{{cite journal |bibcode=1999A&A...352..555A |title=Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures |last1=Allende Prieto |first1=C. |last2=Lambert |first2=D. L. |journal=Astronomy and Astrophysics |date=1999 |volume=352 |page=555 |arxiv=astro-ph/9911002 }}</ref>
<ref name=houk1978>{{citation | last1=Houk | first1=Nancy | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=2 | location=Ann Arbor | publisher=Dept. of Astronomy, University of Michigan | year=1978 | bibcode=1978mcts.book.....H | postscript=. }}</ref>
<ref name=Kharchenko2007>{{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 | year=2007 | doi=10.1002/asna.200710776 | arxiv=0705.0878 | bibcode=2007AN....328..889K | s2cid=119323941 | postscript=. }}</ref>
</references>
==External links== *{{citation | first1=James B. | last1=Kaler | date=August 17, 2012 | title=Kappa Lupi | work=Stars | publisher=University of Illinois | url=http://stars.astro.illinois.edu/sow/kappalup.html | postscript=. | access-date=March 8, 2017 | archive-url=https://web.archive.org/web/20190117031227/http://stars.astro.illinois.edu/sow/kappalup.html | archive-date=January 17, 2019 | url-status=dead }}
{{Stars of Lupus|state=collapsed}}
[[Category:B-type main-sequence stars]] [[Category:A-type main-sequence stars]] [[Category:Be stars]] [[Category:Hyades Stream]] [[Category:Lupus (constellation)]] [[Category:Bayer objects|Lupi, Kappa1]] [[Category:Durchmusterung objects|CD-48 9704 5]] [[Category:Henry Draper Catalogue objects|134481 and 134482]] [[Category:Hipparcos objects|074376 and 074380]] [[Category:Bright Star Catalogue objects|5646 and 5647]]