J/AJ/144/50ivo://CDS.VizieR/J/AJ/144/50doi:10.26093/cds/vizier.51440050CDSYang Y.-G.Li L.-H.Dai H.-F.2017-07-06T06:26:10Z2013-10-07T09:23:42ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.freclipsing-binary-starsinfrared-photometryvisible-astronomybroad-band-photometryWe present BVR photometric observations and several eclipsing times for AV Hya and DZ Cas from 2004 to 2011. Using the Wilson-Devinney method, the photometric solutions with hot spots were deduced from their asymmetric light curves. The results indicate that both stars are Algol-type binaries, whose mass ratio, q_ph_, and fill-out factor of the primary, f_1_, are q_ph_=0.255(+/-0.002) and f_1_=81.2(+/-0.2)% for AV Hya, and q_ph_=0.093(+/-0.003) and f_1_=98.7(+/-0.3)% for DZ Cas. Based on all available light minimum times, it is discovered that the O-C curve of each star could be described by a light-time orbit overlying on a downward parabola. Their periods and amplitudes are P_3_=37.2(+/-0.7)yr and A=0.0095'(+/-0.0006') for AV Hya, and P_3_=62.5(+/-1.0)yr and A=0.0183'(+/-0.0007') for DZ Cas. Cyclic variations may result from the light-time effect due to the third body. The secular period decrease rates are dP/dt=-1.47(+/-0.04)x10^-7^days/yr for AV Hya and dP/dt=-0.92(+/-0.04)x10^-7^days/yr for DZ Cas. This may be interpreted using mass and angular momentum loss from the system. With decreasing period, the fill-out factor of the primary increases and it may finally fill its inner Roche lobe. Therefore, AV Hya and DZ Cas with a secular period decrease will evolve from semi-detached configurations into contact ones.2012AJ....144...50Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/144/50CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2012)B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2013)II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)II/150 : Parameters of eclipsing binaries (Brancewicz+, 1980)J/AJ/143/13 : Al Gem and BM Mon light curves - Paper III (Yang+, 2012)J/other/IBVS/5984 : Minima and maxima of 503 variables (Hubscher, 2011)J/other/JAVSO/38.183 : Time of minima of eclipsing binaries (Samolyk+, 2010)J/other/IBVS/5918 : Minima and maxima of 452 variables (Hubscher+, 2010)J/AJ/139/1360 : AO Ser VR light curves - Paper II (Yang+, 2010)J/AJ/137/226 : TV Tri differential light curves - Paper I (Yang+, 2009)J/A+A/446/785 : Catalogue of eclipsing variables (Malkov+, 2006)J/other/IBVS/5493 : 2003 CCD minima of eclipsing binaries (Nelson+, 2004)J/A+A/417/263 : Catalogue of Algol type binary stars (Budding+, 2004)J/other/IBVS/5543 : 163-nd list of minima of EBs (Diethelm+, 2004)J/other/IBVS/5296 : Extrema of pulsating stars (Agerer+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/144/50https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/144/50http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/144/50https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/144/50https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/144/50http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/144/50GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/144/50/table1aBVR observations of AV HyarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD-B? Heliocentric Julian Date of B band observationdtime.epochdoublenullableDBmag? Differential B band magnitudemagphot.mag;em.opt.B;arith.difffloatnullableHJD-V? Heliocentric Julian Date of V band observationdtime.epochdoublenullableDVmag? Differential V band magnitudemagphot.mag;em.opt.V;arith.difffloatnullableHJD-R? Heliocentric Julian Date of R band observationdtime.epochdoublenullableDRmag? Differential R band magnitudemagphot.mag;em.opt.R;arith.difffloatnullableJ/AJ/144/50/table1bBVR observations of DZ CasrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD-B? Heliocentric Julian Date of B band observationdtime.epochdoublenullableDBmag? Differential B band magnitudemagphot.mag;em.opt.B;arith.difffloatnullableHJD-V? Heliocentric Julian Date of V band observationdtime.epochdoublenullableDVmag? Differential V band magnitudemagphot.mag;em.opt.V;arith.difffloatnullableHJD-R? Heliocentric Julian Date of R band observationdtime.epochdoublenullableDRmag? Differential R band magnitudemagphot.mag;em.opt.R;arith.difffloatnullableJ/AJ/144/50/table3All compiled light minimum times for AV HyaMinMinimum type (I or II)meta.codenullableEpochEpochtime.epochdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Datedtime.epochdoubleMethDetection method (vi=visual, pg=photographic, CCD=CCD detector and pe=photometric)meta.code;obschar(O-C)1Kreiner et al. (2001aocd.book.....K) ephemeris residuals (1)stat.fit.residualfloat(O-C)2Irwin (1952ApJ...116..211I) light-time orbit residuals (2)stat.fit.residualfloatRef[1/89] Reference, in refs.dat filemeta.ref;pos.frame;meta.fileintJ/AJ/144/50/table5All available times of minimum light for DZ CasrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Datedtime.epochdoubleEpochEpochtime.epochdoubleMethDetection method (vi=visual, pg=photographic, CCD=CCD detector and pe=photometric)meta.code;obscharMinMinimum type (I or II)meta.codenullable(O-C)1Kreiner et al. (2001aocd.book.....K) ephemeris residuals (1)stat.fit.residualfloat(O-C)2Irwin (1952ApJ...116..211I) light-time orbit residuals (2)stat.fit.residualfloatRef[1/89] Reference, in refs.dat filemeta.ref;pos.frame;meta.fileintJ/AJ/144/50/refsReferencesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRef[1/89] Reference numbermeta.id;meta.mainintprimaryBibCodeBibliographic codemeta.bib.bibcodecharAutAuthor's namemeta.bib.authorcharComCommentsmeta.notechar