{{Short description|Triple star system in the constellation Lupus}} {{Starbox begin}} {{Starbox image | image = {{Location mark | image=Lupus IAU.svg | float=center | width=240 | position=right | mark=Red circle.svg | mark_width=10 | mark_link=γ Lup | x%=43.1 | y%=44.5 }} | caption = Location of γ Lupi (circled) }} {{Starbox observe | epoch = [[J2000.0]] | constell = [[Lupus (constellation)|Lupus]] | ra = {{RA|15|35|08.44835}}<ref name=aaa474_2_653/> | dec = {{DEC|−41|10|00.3247}}<ref name=aaa474_2_653/> | appmag_v = 2.77<ref name=aaa216_1_44/> }} {{Starbox character | class = B2 IV<ref name=mnras410_1_190/> | b-v = −0.20<ref name=clpl4_99/> | u-b = −0.82<ref name=clpl4_99/> | variable = }} {{Starbox astrometry | radial_v = +2.3<ref name=rgcrv/> | prop_mo_ra = −15.62<ref name=aaa474_2_653/> | prop_mo_dec = −25.43<ref name=aaa474_2_653/> | parallax = 7.75 | p_error = 0.50 | parallax_footnote = <ref name=aaa474_2_653/> | absmag_v = −2.4<ref name=aaa216_1_44/> }} {{Starbox orbit | primary = Aa | name = Ab | reference = <ref name="Jerzykiewicz"/> | period_unitless = 2.85 days | axis_unitless = {{val|16.0|-|19.3|ul=solar radius}} | eccentricity = 0 | k1 = {{val|26.7|1.0}} }} {{Starbox orbit | primary = A | name = B | reference = <ref name="Jerzykiewicz"/> | period = {{Val|167.3|21.5|7.2}} | axis = {{Val|0.970|0.343|0.240|ul="}} | axis_unitless = {{val|125|ul=AU}} | eccentricity= {{Val|0.826|0.082|0.181}} | inclination = {{Val|93.04|1.45|0.89}} | node = {{Val|91.20|0.52|0.35}} | periastron = {{Val|1885.7|2.9|4.0|fmt=none}} | periarg = {{Val|286.9|12.0|5.9}} }} {{Starbox detail | source = <ref name="Jerzykiewicz"/> | component1 = γ Lup Aa | mass = {{val|6|-|10}} | radius = {{Val|3.92|-|5.39}} | luminosity = {{val|2570|-|4700|fmt=commas}} | gravity = {{Val|3.867|-|4.130}} | age_myr = {{val|16.7|5.0|6.6}} | temperature = 20,900<ref name=aaa216_1_44/> | rotational_velocity = 270<ref name=coapa239_1/> | component2 = γ Lup Ab | mass2 = {{Val|0.72|-|1.93}} | luminosity2 = {{val|2.39|-|10.7}} | radius2 = {{val|2.00|-|3.47}} | temperature2= {{val|4140|-|7210|fmt=commas}} | gravity2 = {{val|3.515|-|3.803}} }} {{Starbox catalog | names = {{odlist | B=γ Lup | CD=−40°9760 | HD=138690 | HIP=76297 | HR=5776 | SAO=225938 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = gam+Lup }} {{Starbox end}}
'''Gamma Lupi''', [[Romanization of Greek|Latinized]] from γ Lupi, is a triple [[star system]] in the [[constellation]] of [[Lupus (constellation)|Lupus]]. It is easily visible to the [[naked eye]], having an [[apparent magnitude]] of 2.77. It is also known in ancient [[Chinese language|Chinese]] astronomy as 騎官一 or "the 1st (star) of the Cavalry Officer". With a telescope, Gamma Lupi can be resolved into a binary star system in close orbit. This is known as the Gamma Lupi AB system, often abbreviated as γ Lupi AB or γ Lup AB.
[[File:GammaLupLightCurve.png|thumb|left|A [[light curve]] for Gamma Lupi, plotted from ''[[Transiting Exoplanet Survey Satellite|TESS]]'' data<ref name=MAST/>]] The system has a hierarchical architecture. The primary, Gamma Lupi A is itself a [[spectroscopic binary]] with an orbital period of 2.849769 days.<ref name="Jerzykiewicz"/> Although the system does not show eclipses, the hotter star of the pair heats the side of the cooler star that faces it, and as they orbit each other the combined starlight varies in brightness by about 0.02 magnitudes, as seen from the Earth.<ref name="IVSI"/> The outer component, Gamma Lupi B, is widely-separated (125 [[astronomical unit]]s) and has an orbital period of 170 years.<ref name="Jerzykiewicz"/>
This star is a [[proper motion]] member of the Upper Centaurus–Lupus sub-group in the [[Scorpius–Centaurus association|Scorpius–Centaurus]] [[Stellar association|OB association]], the nearest such co-moving association of massive stars to the Sun.<ref name=aaa216_1_44/> {{clear left}}
== See also == * [[Traditional Chinese star names#Lupus]]
==References== {{Reflist|30em|refs=
<ref name=aaa474_2_653>{{citation | first=F. | last=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 |arxiv = 0708.1752 | s2cid=18759600 }}</ref>
<ref name="IVSI">{{cite web |title=gam Lup |url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=17893 |website=The International Variable Star Index |publisher=AAVSO |access-date=16 December 2022}}</ref>
<ref name=aaa216_1_44>{{citation | last1=de Geus | first1=E. J. | last2=de Zeeuw | first2=P. T. | last3=Lub | first3=J. | title=Physical parameters of stars in the Scorpio-Centaurus OB association | journal=Astronomy and Astrophysics | volume=216 | issue=1–2 | pages=44–61 |date=June 1989 | bibcode=1989A&A...216...44D }}</ref>
<ref name=MAST>{{cite web |title=MAST: Barbara A. Mikulski Archive for Space Telescopes |url=https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html |publisher=Space Telescope Science Institute |access-date=8 December 2021}}</ref>
<ref name="Jerzykiewicz">{{cite journal |last1=Jerzykiewicz |first1=M. |last2=Pigulski |first2=A. |last3=Michalska |first3=G. |last4=Moździerski |first4=D. |last5=Ratajczak |first5=M. |last6=Handler |first6=G. |last7=Moffat |first7=A. F. J. |last8=Pablo |first8=H. |last9=Popowicz |first9=A. |last10=Wade |first10=G. A. |last11=Zwintz |first11=K. |title=BRITE observations of ν Centauri and γ Lupi, the first non-eclipsing members of the new class of nascent binaries |journal=Monthly Notices of the Royal Astronomical Society |date=June 2021 |volume=503 |issue=4 |pages=5554–5568 |doi=10.1093/mnras/stab846 |doi-access=free |arxiv=2104.11770 |bibcode=2021MNRAS.503.5554J}}</ref>
<ref name=SIMBAD>{{cite simbad | title=* gam Lup | access-date=2007-01-18 }}</ref>
<ref name=mnras410_1_190>{{citation | last1=Tetzlaff | first1=N. | last2=Neuhäuser | first2=R. | last3=Hohle | first3=M. M. | title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=410 | issue=1 | pages=190–200 |date=January 2011 | doi=10.1111/j.1365-2966.2010.17434.x | doi-access=free | bibcode=2011MNRAS.410..190T |arxiv = 1007.4883 | s2cid=118629873 }}</ref>
<ref name=rgcrv>{{citation | last=Evans | first=D. S. | date=June 20–24, 1966 | editor1-last=Batten | editor1-first=Alan Henry | editor2-last=Heard | editor2-first=John Frederick | title=The Revision of the General Catalogue of Radial Velocities | work=Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 | volume=30 | page=57 | location=University of Toronto | publisher=[[International Astronomical Union]] | bibcode=1967IAUS...30...57E }}</ref>
<ref name=coapa239_1>{{citation | last1=Bernacca | first1=P. L. | last2=Perinotto | first2=M. | title=A catalogue of stellar rotational velocities | journal=Contributi Osservatorio Astronomico di Padova in Asiago | volume=239 | issue=1 | date=1970 | page=1 | bibcode=1970CoAsi.239....1B }}</ref>
<ref name=clpl4_99>{{citation | display-authors=1 | 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 | date=1966 | page=99 | bibcode=1966CoLPL...4...99J }}</ref>
}}
{{Stars of Lupus}} <!-- Properties --> [[Category:B-type subgiants]] [[Category:Triple star systems]] [[Category:Upper Centaurus Lupus]] <!-- Other --> [[Category:Lupus (constellation)]] [[Category:Bayer objects|Lupi, Gamma]] [[Category:Durchmusterung objects|CD-40 09760]] [[Category:Henry Draper Catalogue objects|138690]] [[Category:Hipparcos objects|076297]] [[Category:Bright Star Catalogue objects|5776]]