GG Lupi

{{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=GG Lupi |x=490|y=665 }} | caption = Location of GG Lupi (circled in red) }} {{Starbox observe | epoch = J2000 | ra = {{RA|15|18|56.3747}}<ref name=dr3/> | dec = {{DEC|-40|47|17.597}}<ref name=dr3/> | appmag_v = 5.58–6.11<ref name="IVSI"/> | constell = [[Lupus (constellation)|Lupus]] }} {{Starbox character | class = B7V (primary) B9V (secondary) | b-v = −0.099<ref name="Budding"/> | u-b = −0.46<ref name="Budding"/> | variable = [[algol variable|Algol]]<ref name="IVSI"/> }} {{Starbox astrometry | radial_v = {{Val|+4.0|1.0}}<ref name="Budding"/> | prop_mo_ra = −19.219<ref name=dr3/> | prop_mo_dec = −21.791<ref name=dr3/> | parallax = 6.6639 | p_error = 0.0894 | parallax_footnote = <ref name=dr3/> | absmag_v = −0.53<ref name=xhip/> }} {{Starbox orbit | reference = <ref name="Budding"/> | period = | period_unitless = {{val|1.8495927|ul=d}} | axis_unitless = {{val|12.01|ul=AU}} | inclination = 87.5 | eccentricity = 0.15 | periastron = | k1 = }} {{Starbox detail | source = | component1 = Primary | mass = {{val|4.16|0.12}}<ref name="Budding"/> | temperature = 13,000<ref name="Budding"/> | radius = {{val|2.42|0.05}}<ref name="Budding"/> | luminosity = | gravity = 4.28<ref name="Budding"/> | rotational_velocity = {{val|97|8}}<ref name=marcussen2022/> | rotation = | component2 = Secondary | mass2 = {{val|2.64|0.12}}<ref name="Budding"/> | temperature2 = 10,600<ref name="Budding"/> | radius2 = {{val|1.79|0.04}}<ref name="Budding"/> | luminosity2 = | gravity2 = 4.30<ref name="Budding"/> | rotational_velocity2 = {{val|61|5}}<ref name=marcussen2022/> | rotation2 = | age_myr2 = 20<ref name=Andersen/> }}

{{Starbox catalog | names = {{odlist | HD=135876 | HIP=74950 | HR=5687 | SAO=225647 | 2MASS=J15185637-4047176}}<ref name=SIMBAD/> }} {{Starbox reference |Simbad=GG+Lup }} {{Starbox end}}

'''GG Lupi''' is an [[eclipsing binary]] star in the southern constellation of [[Lupus (constellation)|Lupus]]. Most of the time it is a [[apparent magnitude|magnitude]] 5.6 object, making it faintly visible to the naked eye, but during the primary eclipse its brightness falls to 6.1.<ref name="IVSI"/> GG Lupi is located one half-degree (one full moon diameter) west of the third-magnitude star [[Delta Lupi]].

[[File:GGLupLightCurve.png|thumb|left|A [[light curve]] for GG Lupi, plotted from [[TESS]] data<ref name=MAST/>]] This star was found to be a [[spectroscopic binary]] in 1930,<ref name="Neubauer"/> and its eclipses were detected in observations during 1964.<ref name="Smith"/> Its location in the sky, distance (~490 [[light-year]]s)<ref name=dr3/> and [[proper motion]] make it a likely member of the [[Scorpius–Centaurus association]] within the [[Gould's Belt]] star-formation region.<ref name="Budding"/> The two stars comprising this binary are both very young main-sequence stars of [[B-type main-sequence star|spectral type B]]. They are estimated to be about 20 million years old, placing them near the [[Main sequence#Formation and evolution|zero-age main sequence]].<ref name="Andersen"/> Their orbit is somewhat eccentric (''e''=0.15) and the period of [[apsidal precession]] is 102 years.<ref name="Wolf"/>

{{clear left}} ==References== <references>

<ref name=SIMBAD>{{cite simbad | title=V* GG Lup -- Eclipsing Binary | work=SIMBAD Astronomical Object Database | access-date=2022-12-10 }}</ref>

<ref name=xhip>{{cite journal | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | title=XHIP: An extended hipparcos compilation | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>

<ref name=marcussen2022>{{cite journal |bibcode=2022ApJ...933..227M |title=The BANANA Project. VI. Close Double Stars are Well Aligned with Noticeable Exceptions; Results from an Ensemble Study Using Apsidal Motion and Rossiter-McLaughlin Measurements |last1=Marcussen |first1=Marcus L. |last2=Albrecht |first2=Simon H. |journal=The Astrophysical Journal |year=2022 |volume=933 |issue=2 |page=227 |doi=10.3847/1538-4357/ac75c2 |arxiv=2112.00824 |s2cid=244799745 |doi-access=free }}</ref>

<ref name="IVSI">{{cite web | title=GG Lup | url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=17783 | website=The International Variable Star Index | publisher=AAVSO | access-date=10 December 2022}}</ref>

<ref name="Wolf">{{cite journal | last1=Wolf | first1=M. | last2=Zejda | first2=M. | title=Apsidal motion in southern eccentric eclipsing binaries: V539 Ara, GG Lup, V526 Sgr and AO Vel | journal=Astronomy and Astrophysics | date=July 2005 | volume=437 | issue=2 | pages=545–551 | doi=10.1051/0004-6361:20041868 | bibcode=2005A&A...437..545W | s2cid=121307009 | doi-access=free }}</ref>

<ref name="Neubauer">{{cite journal | last=Neubauer | first=F. J. | title=Forty-two Spectroscopic Binary Stars | journal=Publications of the Astronomical Society of the Pacific | date=August 1930 |volume=42 | issue=248 | page=235 | doi=10.1086/124043 | bibcode=1930PASP...42..235N | s2cid=121035980 }}</ref>

<ref name="Andersen">{{cite journal | last1=Andersen | first1=J. | last2=Clausen | first2=J. V. | last3=Gimenez | first3=A. | title=Absolute dimensions of eclipsing binaries. XX. GG LUPI : young metal-deficient B stars | journal=Astronomy and Astrophysics | date=October 1993 | volume=277 | pages=439–451 | bibcode=1993A&A...277..439A }}</ref>

<ref name="Smith">{{cite journal | last=Smith | first=Lindsey F. | title=HR 5687: A New Eclipsing Binary | journal=Publications of the Astronomical Society of the Pacific | date=April 1966 | volume=78 | issue=462 | page=168 | doi=10.1086/128320 | bibcode=1966PASP...78..168S | s2cid=120477301 | doi-access=free }}</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=10 December 2022}}</ref>

<ref name="Budding">{{cite journal | last1=Budding | first1=E. | last2=Butland | first2=R. | last3=Blackford | first3=M. | title=Absolute parameters of young stars: GG Lup and μ1 Sco | journal=Monthly Notices of the Royal Astronomical Society | date=April 2015 | volume=448 | issue=4 | pages=3784–3796 | doi=10.1093/mnras/stv234 | doi-access=free | arxiv=1502.04360 | bibcode=2015MNRAS.448.3784B }}</ref>

</references>

[[Category:Spectroscopic binaries]] [[Category:Algol variables]] [[Category:Henry Draper Catalogue objects|135876]] [[Category:Hipparcos objects|74950]] [[Category:Objects with variable star designations|Lupi, GG]] [[Category:B-type main-sequence stars]] [[Category:Bright Star Catalogue objects|5687]] [[Category:Lupus (constellation)]]