J/AJ/149/146ivo://CDS.VizieR/J/AJ/149/146doi:10.26093/cds/vizier.51490146CDSSamec R.G.Benkendorf B.Dignan J.B.Robb R.Kring J.Faulkner D.R.2017-07-06T06:25:27Z2015-05-12T14:44:08ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsinfrared-photometryvisible-astronomybroad-band-photometryHR Bootis is a neglected binary that is found to be a solar-type (G2V) extreme mass ratio binary (EMRB). It was discovered by Hanley & Shapley in 1940. Surprisingly, little has been published in the intervening years. In 1999 it was characterized by a 0.31587day orbital period. Since that time it has been observed by various observers who have determined ~20 timings of minimum light over the past ~15000 orbits. Our observations in 2012 represent the first precision curves in the BVR_c_I_c_Johnson-Cousins wavelength bands. The light curves have rather low amplitudes, averaging some 0.5 magnitudes, yet they exhibit total eclipses, which is typical of the rare group of solar-type EMRBs. An improved linear ephemeris was computed along with a quadratic ephemeris showing a decaying orbit, which indicates magnetic breaking may be occurring. The light curve solution reveals that HR Boo is a contact system with a somewhat low 21% Roche-lobe fill-out but a mass ratio of q=4.09 (0.2444), which defines it as an EMRB. Two spots, both hot, were allowed to iterate to fit the light curve asymmetries. Their radii are 32{deg} and 16{deg}. Both are high-latitude polar spots indicative of strong magnetic activity. The shallow contact yet nearly equal component temperatures makes it an unusual addition to this group.2015AJ....149..146Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/149/146CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)J/AJ/149/90 : UBVRI light curves of GSC 3208-1986 (Samec+, 2015)J/AJ/149/48 : BVRI light curves of ZZ Eri (Samec+, 2015)J/AJ/147/3 : BV(RI)c light curves of V2421 Cyg (Samec+, 2014)J/AJ/145/14 : BV(RI)c light curves of V1043 Cas (Samec+, 2013)J/PASP/124/693 : HO Psc UBV(RI)c light curves (Samec+, 2012)J/AJ/142/117 : UBVRcIc differential photometry of V1853 Ori (Samec+, 2011)J/other/IBVS/5918 : Minima and maxima of 452 variables (Hubscher+, 2010)J/other/IBVS/5863 : 79th Name-List of Variable Stars (Kazarovets+, 2008)J/AJ/131/621 : Catalog of 1022 bright contact binary stars (Gettel+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/149/146https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/149/146http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/149/146https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/149/146https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/149/146http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/149/146GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfraredOpticaldefaultJ/AJ/149/146/photometryUBVRI photometry of HR BooFltFilterinstr.bandpasscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDmag[0.5/1.1] Johnson-Cousins instrumental {Delta} magnitude (1)magphot.mag;arith.difffloatHJDHeliocentric Julian Date (HJD-2455800)dtime.epochfloat