J/AJ/149/168ivo://CDS.VizieR/J/AJ/149/168doi:10.26093/cds/vizier.51490168CDSPapageorgiou A.Christopoulou P.-E.2017-06-19T07:58:08Z2015-05-29T16:02:49ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsinfrared-photometryvisible-astronomyphotometryccd-photometryWe present a detailed investigation of the low-amplitude contact binary HI Dra based on the new VR_c_I_c_ CCD photometric light curves (LCs) combined with published radial velocity (RV) curves. Our completely covered LCs were analyzed using PHOEBE and revealed that HI Dra is an overcontact binary with low fill-out factor f=24+/-4(%) and temperature difference between the components of 330K. Two spotted models are proposed to explain the LC asymmetry, between which the A subtype of W UMa type eclipsing systems, with a cool spot on the less massive and cooler component, proves to be more plausible on evolutionary grounds. The results and stability of the solutions were explored by heuristic scan and parameter perturbation to provide a consistent and reliable set of parameters and their errors. Our photometric modeling and RV curve solution give the following absolute parameters of the hot and cool components, respectively: M_h_=1.72+/-0.08M_{sun}_ and M_c_=0.43+/-0.02M_{sun}_, R_h_=1.98+/-0.03R_{sun}_ and R_c_=1.08+/-0.02R_{sun}_, and L_h_=9.6+/-0.1L_{sun}_ and L_c_=2.4+/-0.1L_{sun}_. Based on these results the initial masses of the progenitors (1.11+/-0.03M_{sun}_ and 2.25+/-0.07M_{sun}_, respectively) and a rough estimate of the age of the system of 2.4Gyr are discussed.2015AJ....149..168Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/149/168CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/148/126 : Light curves of four overcontact binaries (Caliskan+, 2014)J/AJ/146/157 : Differential BVRI photometry of FI Boo (Christopoulou+, 2013)J/AJ/146/70 : Spectroscopy of W UMa-type binary stars (Rucinski+, 2013)J/AJ/144/149 : CCD photometry of the W UMa type TY Boo (Christopoulou+, 2012)J/AJ/143/30 : CCD photometry of V380 Cas (Christopoulou+, 2012)J/AJ/142/99 : BVRI observations of TZ Boo (Christopoulou+, 2011)J/AJ/137/3655 : Radial velocities of 8 close binaries (Pribulla+, 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/149/168https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/149/168http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/149/168https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/149/168https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/149/168http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/149/168GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/149/168/table1VR_c_I_c_ observational data for the eclipsing binary HI DrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD-V? Heliocentric Julian Date of V-band observationdtime.epochdoublenullableDVmag? Delta V-band magnitude (1)magphot.mag;em.opt.VfloatnullableHJD-R? Heliocentric Julian Date of Rc-band observationdtime.epochdoublenullableDRmag? Delta Rc-band magnitude (1)magphot.mag;em.opt.RfloatnullableHJD-IHeliocentric Julian Date of Ic-band observationdtime.epochdoubleDImagDelta Ic-band magnitude (1)magphot.mag;em.opt.Ifloat