J/AJ/149/62ivo://CDS.VizieR/J/AJ/149/62doi:10.26093/cds/vizier.51490062CDSXiang F.-Y.Yu Y.-X.Xiao T.-Y.2017-07-12T06:59:25Z2015-02-24T15:09:09ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsinfrared-photometryvisible-astronomybroad-band-photometryccd-photometryIn this paper, new CCD photometric observations of V508 Oph obtained in 2009 and 2010 at the Xinglong Observatory are presented. From the new observations, six new times of minimum light were derived. The light curves were analyzed by using the 2003 version of the Wilson-Devinney program. It is found that the asymmetric light curves can be modeled by a hot spot on the secondary component. The degree of overcontact is 15.4%, implying that the system is a shallow-contact binary. Combining the new times of minimum light with the photoelectric and CCD data compiled from the database, we investigate its orbital period. The results show that the orbital period may be undergoing multiple changes: a long-term decrease at a rate of dP/dt=-(1.502+/-0.063)x10^-7^days/year, and a small periodic variation with a period of 24.27(+/-0.34) years. Since V508 Oph is an overcontact system and both components are late-type stars, we discuss the possible connection between the mass transfer, magnetic activity, the third body, and the orbital period changes.2015AJ....149...62Xhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/149/62CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)J/AJ/146/35 : BVR light curves of DZ Psc (Yang+, 2013)J/AJ/143/122 : VR light curves of CK Boo (Yang+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/149/62https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/149/62http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/149/62https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/149/62https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/149/62http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/149/62GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/149/62/photoCombined table from original tablesPhasePhase (1)time.phasefloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBandSimbad column added by the CDSinstr.bandpasscharHJDHeliocentric Julian Date (HJD-2450000)dtime.epochdoubleDmagThe {Delta} magnitudemagphot.mag;arith.difffloat