J/AJ/164/202ivo://CDS.VizieR/J/AJ/164/202doi:10.26093/cds/vizier.51640202CDSLi K.Gao X.Liu X.-Y.Gao X.Li L.-Z.Chen XuSun G.-Y.2023-03-20T14:35:40Z2022-12-13T09:18:27ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsvisible-astronomyspectroscopyThe photometric and spectroscopic investigations of ten contact binaries were presented for the first time. It is discovered that the mass ratios of all the ten targets are smaller than 0.15, they are extremely low mass ratio contact binaries. Seven of them are deep contact binaries, two are medium contact binaries, while only one is a shallow contact system. Five of them show the O'Connell effect, and a dark spot on one of the two components can lead to a good fit of the asymmetric light curves. The orbital period studies of the ten binaries reveal that they all exhibit long-term period changes, six of them are increasing, while the others are shrinking. The LAMOST spectra were analyzed by the spectral subtraction method, and all the ten targets exhibit excess emissions in the H{alpha} line, indicating chromospheric activity. The evolutionary states of the two components of the ten binaries were studied, and it is found that their evolutionary states are identical to those of the other contact binaries. Based on the study of the relation between orbital angular momentum and total mass, we discovered the ten systems may be at the late evolutionary stage of a contact binary. The initial masses of the two components and the ages of them were obtained. By calculating the instability parameters, we found that the ten contact binaries are relatively stable at present.2022AJ....164..202Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/164/202CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)V/119 : Catalogue of field contact binary stars (Pribulla+, 2003)V/146 : LAMOST DR1 catalogs (Luo+, 2015)J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)J/ApJ/629/1055 : Evolution of close binary systems (Yakut+, 2005)J/MNRAS/373/1483 : W UMa type and CAB stars dynamical evolution (Eker+, 2006)J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)J/A+A/494/209 : Pre-main sequence evolutionary tracks (Landin+, 2009)J/other/RAA/11.924 : Atmospheric parameters for 771 stars (Wu+, 2011)J/AJ/146/157 : Differential BVRI photometry of FI Boo (Christopoulou+, 2013)J/MNRAS/430/2029 : Initial masses of WUMa type contact binaries (Yildiz+, 2013)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/MNRAS/437/185 : W UMa-type contact binaries ages and masses (Yildiz, 2014)J/AJ/157/207 : BVR_c_I_c_ light curve observations for VZ Lib (Liao+, 2019)J/ApJS/244/43 : Binary stars parameters LAMOST & Kepler obs. (Zhang+, 2019)J/AJ/159/189 : Eclipse timings for 9 contact binaries (Li+, 2020)J/AJ/162/13 : Parameters estimation for 173 eclipsing binaries (Li+, 2021)J/AJ/161/221 : Photometry & spectroscopy of 4 binaries stars (Panchal+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/164/202https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/164/202http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/164/202https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/164/202https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/164/202http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/164/202GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/164/202/table1 (Information of the 10 systems from ASAS-SN database)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/164/202/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/164/202/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/164/202/table1?GETtext/xml+votable180.050000true3.593795841.89201640.0055555555555555566/1266 1916 2332 2726 4947 5962 6742 8480 20046 27708https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/164/202?format=asciiOpticaldefaultJ/AJ/164/202/table1Information of the 10 systems from ASAS-SN databaseASASASAS-SN Namemeta.id;meta.maincharONameOther namemeta.idcharIDIdentifier in this workmeta.idcharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPer[0.28/0.63] Perioddtime.perioddoubleHJD[8812/9483] Heliocentric Julian Date; HJD-2450000dtime.epochdoublee_HJD[0.0002/0.002] Error on HJDdstat.error;time.epochdoubleVmag[11.6/14.9] V-band magnitudemagphot.mag;em.opt.VfloatAmp[0.26/0.39] Amplitudemagphot.magfloatNeclNumber of eclipse times observations (table6)meta.numberintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.mainJ/AJ/164/202/table6Eclipse times of ten targetsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintASASASASSN-V namemeta.id;meta.maincharIDIdentifier used in this workmeta.idcharBJD[2452749/2459483] Barycentric Julian date of eclipsedtime.epochdoublee_BJD[0/0.02] Uncertainty in BJDdstat.errorfloatEclipse[-21145/1068] Eclipse numbermeta.iddoubleO-C[-0.044/0.09] Observed - Calculatedstat.fit.residualfloatRes[-0.013/0.06] Residualsstat.fit.residualfloatRef[1/10] References(s) used (1)meta.refint