J/AJ/153/137ivo://CDS.VizieR/J/AJ/153/137doi:10.26093/cds/vizier.51530137CDSNasiroglu I.Gozdziewski K.Slowikowska A.Krzeszowski K.Zejmo M.,Zola S.Er H.Ogloza W.Drozdz M.Koziel-Wierzbowska D.Debski B.,Karaman N.2018-09-18T13:40:02Z2018-05-14T08:14:42ZCDS support team

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

cds-question@unistra.freclipsing-binary-starssubdwarf-starsexoplanetsThe cyclic behavior of (O-C) residuals of eclipse timings in the sdB+M eclipsing binary NSVS 14256825 was previously attributed to one or two Jovian-type circumbinary planets. We report 83 new eclipse timings that not only fill in the gaps in those already published but also extend the time span of the (O-C) diagram by three years. Based on the archival and our new data spanning over more than 17 years, we re-examined the up-to-date system (O-C). The data revealed a systematic, quasi-sinusoidal variation deviating from an older linear ephemeris by about 100 s. It also exhibits a maximum in the (O-C) near JD 2456400 that was previously unknown. We consider two most credible explanations of the (O-C) variability: the light propagation time due to the presence of an invisible companion in a distant circumbinary orbit, and magnetic cycles reshaping one of the binary components, known as the Applegate or Lanza-Rodono effect. We found that the latter mechanism is unlikely due to the insufficient energy budget of the M-dwarf secondary. In the framework of the third-body hypothesis, we obtained meaningful constraints on the Keplerian parameters of a putative companion and its mass. Our best-fitting model indicates that the observed quasi-periodic (O-C) variability can be explained by the presence of a brown dwarf with the minimal mass of 15 Jupiter masses rather than a planet, orbiting the binary in a moderately elliptical orbit (e~0.175) with a period of ~10 years. Our analysis rules out the two-planet model proposed earlier.2017AJ....153..137Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/153/137CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/566/A128 : Period variations in SuperWASP PCEB (Lohr+, 2014)J/AJ/147/45 : Kepler mission. IV. Eclipse times for close binariesJ/MNRAS/453/3474 : ASAS, NSVS, and LINEAR detached eclipsing binarieshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/153/137https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/153/137http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/153/137https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/153/137https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/153/137http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/153/137GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/AJ/153/137/table1List of new NSVS 14256825 eclipse timesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCycle[-26586/31004] Cycle number (G1)meta.id;meta.maindoubleBJDBarycentric Julian Date of minimumdtime.epochdoublee_BJDUncertainty in BJDdstat.errordoubleType[1/2] Eclipse type (1=Primary, 2=Secondary)meta.noteintRef[1/9] Reference (1)meta.ref;pos.frameintJ/AJ/153/137/table3NSVS 14256825 observations logrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateStarting date of observationtime.start;obsnullableCycle[7167.5/31004] Cycle number (G1)meta.id;meta.mainfloatType[1/2] Eclipse type (1=Primary, 2=Secondary)meta.noteintFilterFilter (W-light, R or BG40)meta.id;instr.filtercharExp[3/20] Exposure timestime.duration;obs.exposureintRead[1/20] Readout timestime;arith.difffloatObsObservatory code (1)meta.code;instr.obstycharJ/AJ/153/137/table4List of the NSVS 14256825 eclipse times from the literature and new measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/153]? Data point number (not in table 1)meta.numberintnullableCycle[-26586/31004] Cycle number (G1)meta.id;meta.maindoubleBJDBarycentric Julian Date of minimumdtime.epochdoublee_BJDUncertainty in BJDdstat.errordoublee_BJDs[0/86]? Uncertainty in BJD, in seconds (not in table 1)sstat.errorintnullableType[1/2] Eclipse type (1=Primary, 2=Secondary)meta.noteintRef[1/9] Reference (1)meta.ref;pos.frameint