J/ApJ/753/101ivo://CDS.VizieR/J/ApJ/753/101doi:10.26093/cds/vizier.17530101CDSBarlow B.N.Wade R.A.Liss S.E.2014-03-29T07:17:23Z2014-03-17T14:28:53ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsphotometryThe eclipsing binary system 2M 1938+4603 consists of a pulsating hot subdwarf B star and a cool M dwarf companion in an effectively circular three-hour orbit. The light curve shows both primary and secondary eclipses, along with a strong reflection effect from the cool companion. Here, we present constraints on the component masses and eccentricity derived from the Romer delay of the secondary eclipse. Using six months of publicly available Kepler photometry obtained in short-cadence mode, we fit model profiles to the primary and secondary eclipses to measure their centroid values. We find that the secondary eclipse arrives on average 2.06+/-0.12s after the midpoint between primary eclipses. Under the assumption of a circular orbit, we calculate from this time delay a mass ratio of q=0.2691+/-0.0018 and individual masses of M_sd_=0.372+/-0.024M_{sun}_ and M_c_=0.1002+/-0.0065M_{sun}_ for the sdB and M dwarf, respectively. These results differ slightly from those of a previously published light-curve modeling solution; this difference, however, may be reconciled with a very small eccentricity, ecos{omega}{approx}0.00004. We also report a decrease in the orbital period of \dot{P}=(-1.23+/-0.07)x10^-10^.2012ApJ...753..101Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/753/101CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/133 : Kepler Input Catalog (Kepler Mission Team, 2009)J/PASP/124/1279 : Q3 Kepler's combined photometry (Christiansen+, 2012)J/AJ/143/101 : Kepler B-star variables classification (McNamara+, 2012)J/A+A/529/A89 : Kepler satellite variability study (Debosscher+, 2011)J/AJ/142/160 : Kepler Mission. II. 2165 eclipsing binaries (Slawson+, 2011)J/MNRAS/413/1581 : Candidate subdwarfs and white dwarfs (Gontcharov+, 2011)J/MNRAS/409/1470 : Kepler compact pulsator candidates (Ostensen+, 2010)J/MNRAS/408/L51 : 2M1938+4603 (KIC 9472174) eclipses (Ostensen+, 2010)J/AcA/59/33 : ASAS variable stars in Kepler field. (Pigulski+, 2009)http://archive.stsci.edu/kepler : : MAST Kepler home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/753/101https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/753/101http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/753/101https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/753/101https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/753/101http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/753/101GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/753/101/table1Dates of primary eclipse minimumrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Date eclipse minimum (BJD-2450000)dtime.epochdoublee_BJDError in BJDdstat.errordoubleJ/ApJ/753/101/table2Dates of secondary eclipse minimume_BJDError in BJDdstat.errordoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Date eclipse minimum (BJD-2450000)dtime.epochdouble