{{Short description|Star in the constellation Centaurus}} {{Starbox begin}} {{Starbox image | image = [[Image:V752CenLightCurve.png|250px]] | caption = A [[Photometric system#Photometric letters|visual band]] [[light curve]] for V752 Centauri, plotted from data presented by Sisteró and Castore de Sisteró (1973)<ref name="Sisteró"/> }} {{Starbox observe | epoch = J2000 | constell = [[Centaurus (constellation)|Centaurus]] | ra = {{RA|11|42|48.08}}<ref name=GaiaDR2/> | dec = {{DEC|-35|48|57.5}}<ref name=GaiaDR2/> | appmag_v = 9.10 – 9.66<ref name=Avvakumova2013/> }} {{Starbox character | type = F7/G0(V)<ref name=HOUK1982/> | class = | b-v = | u-b = | variable = [[W Ursae Majoris variable|W UMa]]<ref name=Barone1993/> }} {{Starbox astrometry | radial_v = | prop_mo_ra = −52.175<ref name=GaiaDR2/> | prop_mo_dec = −24.364<ref name=GaiaDR2/> | parallax = 7.9641 | p_error = 0.0495 | parallax_footnote = <ref name=GaiaDR2/> | absmag_v = 4.00 ± 0.34<ref name=Rucinski1997/> }} {{Starbox orbit | reference = | period_unitless = 0.37023198 days<ref name=Zhou2019/> | axis_unitless = 2.59 ± 0.05 {{solar radius}}<ref name=Zhou2019/> | eccentricity = | inclination = 82.07 ± 0.06<ref name=Zhou2019/> | node = | periastron = | periarg = | periarg_primary = | k1 = {{val|83.2|5.7}}<ref name=Sisteró1974/> | k2 = {{val|267.2|6.9}}<ref name=Sisteró1974/> }} {{Starbox detail | age_gyr = 3.84<ref name=Yildiz2014/> }} {{Starbox detail | no_heading=1 | source = | component1=Primary | mass = 1.31 ± 0.07<ref name=Zhou2019/> | radius = 1.30 ± 0.02<ref name=Zhou2019/> | luminosity = 2.00 ± 0.07}<ref name=Zhou2019/> | gravity = | temperature = 5,955 ± 77<ref name=Barone1993/> | metal_fe = | rotational_velocity = | age_gyr = | component2=Secondary | mass2 = 0.39 ± 0.02<ref name=Zhou2019/> | radius2 = 0.77 ± 0.01<ref name=Zhou2019/> | temperature2 = 6,221 ± 81<ref name=Barone1993/> | luminosity2 = 0.75 ± 0.03<ref name=Zhou2019/> }} {{Starbox catalog | names={{odlist | V=V752 Cen| CD=−35°7392 | FK5= | HD=101799 | HIP=57129 | HR= | SAO=202729 | AAVSO= }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = V752+Centauri }} {{Starbox end}}

'''V752 Centauri''' (HD 101799) is [[multiple star system]]<ref name=Schumacher2009/> and [[variable star]] in the [[constellation]] of [[Centaurus (constellation)|Centaurus]]. An [[eclipsing binary]], its [[apparent magnitude]] has a maximum of 9.10, dimming to 9.66 during primary eclipse and 9.61 during secondary eclipse.<ref name=Avvakumova2013/> Its variability was discovered by Howard Bond in 1970.<ref name=Bond1970/> From [[parallax]] measurements by the [[Gaia (spacecraft)|Gaia]] spacecraft, the system is located at a distance of {{Convert|125.6|pc|ly|abbr=off|lk=on|order=flip}} from Earth.<ref name=GaiaDR2/>

V752 Centauri is a [[contact binary]] of the [[W Ursae Majoris variable|W Ursae Majoris]] type, composed of two F-type stars with a combined [[spectral type]] of F7/G0(V).<ref name=HOUK1982/> Individually, the components have been classified as F8&nbsp;+ F5,<ref name=Sisteró1974/> and F8&nbsp;+ F7.5.<ref name=Leung1976/> With [[effective temperature]]s of 5,955 and 6,221&nbsp;[[kelvin|K]],<ref name=Barone1993/> the system is classified as a W Ursae Majoris variable of subtype W, where the secondary star is hotter than the primary; for this reason, the primary eclipses are caused by the occultation of the secondary star.<ref name=Sisteró1974/><ref name=Barone1993/> The system has an [[orbital period]] of only 0.3702 days and a separation of 2.59 [[solar radius|solar radii]]. The orbit is [[inclination|inclined]] by 82° in relation to the plane of the sky.<ref name=Zhou2019/>

The combination of [[photometry (astronomy)|photometric]] and spectroscopic data have allowed the direct determination of the parameters of the stars. The primary component has a mass of 1.31 times the [[solar mass]], radius of 1.30 times the solar radius and a [[luminosity]] double that of [[solar luminosity|the Sun]]. The secondary has only 0.39 times the solar mass, 0.77 times the solar radius, and 0.75 times the solar luminosity.<ref name=Zhou2019/> Since the stars are in contact, there is considerable [[mass transfer]] from the secondary to the primary. It is estimated that the secondary star was initially the more massive star, with 1.76 times the solar mass, while the primary had an initial mass of 0.84 time the solar mass.<ref name=Yildiz2014/> The system's age is estimated at 3.8 billion years.<ref name=Yildiz2014/> All contact binary stars are expected to eventually merge into a single, fast-rotating star.<ref name=Gazeas2008/>

The system's spectrum shows the [[spectral line]]s of a third star, which seems to be a [[K-type main sequence star]]. This third star is itself a [[spectroscopic binary]] with a period of 5.147 days, with a small companion that is probably an M-type [[red dwarf]]. The V752 Centauri system is thus composed of four stars, with two binary pairs that orbit each other.<ref name=Schumacher2009/> Most contact binary stars have one or more distant companions, and were possibly formed by [[angular momentum]] loss due to gravitational interactions with these companion stars.<ref name=Pribulla2006/><ref name=Zhou2019/>

The [[light curve]] analysis of V752 Centauri reveals that between 1970 and 2000, the orbital period of the eclipsing binary remained approximately constant, indicating there was no significant mass transfer. Around the year 2000, the period abruptly increased, possibly accompanied by a slightly dimmer primary eclipse.<ref name=Mallama2015/> Since then, the period has been increasing at a rate of 0.044 seconds per year, which is caused by mass transfer from the less massive star to the more massive one at a rate of 2.52{{e|-7}}&nbsp;{{solar mass}} per year. This period change and the beginning of the mass transfer phase were possibly caused by interactions with the companion binary star.<ref name=Zhou2019/>

==References== <references> <ref name=SIMBAD>{{cite simbad | title=V752 Cen| access-date=14 January 2020 }}</ref>

<ref name=GaiaDR2>{{cite DR2|3464532418676024064}}</ref>

<ref name=Gazeas2008>{{cite journal|bibcode=2008MNRAS.390.1577G|title=Angular momentum and mass evolution of contact binaries|journal=Monthly Notices of the Royal Astronomical Society|volume=390|issue=4|pages=1577|last1=Gazeas|first1=K.|last2=Stȩpień|first2=K.|year=2008|doi=10.1111/j.1365-2966.2008.13844.x|doi-access=free |arxiv=0803.0212|s2cid=14661232}}</ref>

<ref name="Sisteró">{{cite journal |last1=Sisteró |first1=R. F. |last2=Castore de Sisteró |first2=M. E. |title=UBV light variation and orbital elements of HD 101799 |journal=The Astronomical Journal |date=June 1973 |volume=78 |issue=5 |pages=413–421 |doi=10.1086/111435 |bibcode=1973AJ.....78..413S |doi-access=free }}</ref>

<ref name=Avvakumova2013>{{cite journal |bibcode=2013AN....334..860A |title=Eclipsing variables: Catalogue and classification |journal=Astronomische Nachrichten |volume=334 |issue=8 |pages=860 |last1=Avvakumova |first1=E. A. |last2=Malkov |first2=O. Yu. |last3=Kniazev |first3=A. Yu. |year=2013 |doi=10.1002/asna.201311942 |hdl=10995/27061 |hdl-access=free }}</ref>

<ref name=HOUK1982>{{citation | title=Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars | journal=Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume_3. Declinations -40_ƒ0 to -26_ƒ0 | volume=3 | last1=Houk | first1=Nancy | location=Ann Arbor, Michigan | publisher=Dept. of Astronomy, University of Michigan | year=1982 | bibcode=1982mcts.book.....H }}</ref>

<ref name=Barone1993>{{cite journal|bibcode=1993ApJ...407..237B|title=Analysis of Contact Binary Systems: AA Ursae Majoris, V752 Centauri, AO Camelopardalis, and V677 Centauri|journal=The Astrophysical Journal|volume=407|pages=237|last1=Barone|first1=F.|last2=Di Fiore|first2=L.|last3=Milano|first3=L.|last4=Russo|first4=G.|year=1993|doi=10.1086/172509}}</ref>

<ref name=Rucinski1997>{{cite journal|bibcode=1997PASP..109.1340R|title=Absolute Magnitude Calibration for the W UMa-Type Systems Based on HIPPARCOS Data|journal=Publications of the Astronomical Society of the Pacific|volume=109|pages=1340|last1=Rucinski|first1=S. M.|last2=Duerbeck|first2=H. W.|year=1997|doi=10.1086/134014|arxiv=astro-ph/9710214|doi-access=free}}</ref>

<ref name=Zhou2019>{{cite journal|bibcode=2019MNRAS.489.4760Z|title=V752 Cen – a triple-lined spectroscopic contact binary with sudden and continuous period changes|journal=Monthly Notices of the Royal Astronomical Society|volume=489|issue=4|pages=4760|last1=Zhou|first1=X.|last2=Soonthornthum|first2=B.|last3=Qian|first3=S. -B.|last4=Fernández Lajús|first4=E.|year=2019|doi=10.1093/mnras/stz2508|doi-access=free |arxiv=1909.06038|s2cid=202572782}}</ref>

<ref name=Sisteró1974>{{cite journal|bibcode=1974AJ.....79..391S|title=Radial velocity curves of HD 101799|journal=The Astronomical Journal|volume=79|pages=391|last1=Sisteró|first1=R. F.|last2=Castore De Sisteró|first2=M. E.|year=1974|doi=10.1086/111556}}</ref>

<ref name=Yildiz2014>{{cite journal|last=Yildiz|date=2014|title=Origin of W UMa-type contact binaries – age and orbital evolution|journal=Monthly Notices of the Royal Astronomical Society | volume=437 | issue=1 |pages=185–94 | doi=10.1093/mnras/stt1874 |doi-access=free |bibcode=2014MNRAS.437..185Y|arxiv = 1310.5526 |s2cid=119121897}}</ref>

<ref name=Schumacher2009>{{cite journal|bibcode=2009ASPC..404..199S|title=Analysis of the W UMa-type Eclipsing Binary V752 Centauri|journal=The Eighth Pacific Rim Conference on Stellar Astrophysics: A Tribute to Kam-Ching Leung|volume=404|pages=199|last1=Schumacher|first1=H.|year=2009}}</ref>

<ref name=Bond1970>{{cite journal|bibcode=1970PASP...82.1065B|title=Three Eclipsing Binaries Found Spectroscopically|journal=Publications of the Astronomical Society of the Pacific|volume=82|issue=489|pages=1065|last1=Bond|first1=Howard E.|year=1970|doi=10.1086/129004|doi-access=free}}</ref>

<ref name=Leung1976>{{cite journal|bibcode=1976PASP...88..936L|title=The contact binary HD 101799|journal=Publications of the Astronomical Society of the Pacific|volume=88|pages=936|last1=Leung|first1=K. -C|year=1976|doi=10.1086/130049|doi-access=free}}</ref>

<ref name=Pribulla2006>{{cite journal | title=Contact Binaries with Additional Components. I. The Extant Data | last1=Pribulla | first1=T. | last2=Rucinski | first2=S. M. | journal=The Astronomical Journal | volume=131 | issue=6 | pages=2986–3007 | year=2006 | bibcode=2006AJ....131.2986P| arxiv=astro-ph/0601610 | doi=10.1086/503871| s2cid=15762240 }}</ref>

<ref name=Mallama2015>{{cite journal|bibcode=2015JAVSO..43...38M|title=Sudden Period Change and Dimming of the Eclipsing Binary V752 Centauri|journal=Journal of the American Association of Variable Star Observers (Jaavso)|volume=43|issue=1|pages=38|last1=Mallama|first1=A.|last2=Pavlov|first2=H.|year=2015}}</ref> </references>

{{Stars of Centaurus}}

[[Category:W Ursae Majoris variables]] [[Category:Centaurus]] [[Category:F-type main-sequence stars]] [[Category:K-type main-sequence stars]] [[Category:Multiple star systems|4]] [[Category:Spectroscopic binaries]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|101799]] [[Category:Hipparcos objects|057129]] [[Category:Objects with variable star designations|Centauri, V752]]