J/AJ/164/102ivo://CDS.VizieR/J/AJ/164/102doi:10.26093/cds/vizier.51640102CDSMalpas A.Albrow M.D.Yee J.C.Gould A.Udalski A.Martin A.H.,Beichman C.A.Bryden G.Novati S.C.Carey S.Henderson C.B.Gaudi B.S.,Shvartzvald Y.Zhu W.Cha S.-M.Chung S.-J.Han C.Hwang K.-H.,Jung Y.K.Kim D.-J.Kim H.-W.Kim S.-L.Lee C.-U.Lee D.-J.Lee Y.,Park B.-G.Pogge R.W.Ryu Y.-H.Shin I.-G.Zang W.Iwanek P.,Kozlowski S.Mroz P.Pietrukowicz P.Poleski R.Rybicki K.A.,Skowron J.Soszynski I.Szymanski M.K.Ulaczyk K.Spitzer team,KMTNet CollaborationOGLE Collaboration2023-09-27T10:25:34Z2022-12-02T06:41:39ZCDS support team

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

cds-question@unistra.frgravitational-lensingbrown-dwarfsmultiple-starsinfrared-photometryvisible-astronomyphotometryWe report the analysis of microlensing event OGLE-2017-BLG-1038, observed by the Optical Gravitational Lensing Experiment, Korean Microlensing Telescope Network, and Spitzer telescopes. The event is caused by a giant source star in the Galactic Bulge passing over a large resonant binary-lens caustic. The availability of space-based data allows the full set of physical parameters to be calculated. However, there exists an eightfold degeneracy in the parallax measurement. The four best solutions correspond to very-low-mass binaries near (M_1_=170_-50_^+40^M_J_ and M_2_=110_-30_^+20^M_J_), or well below (M_1_=22.5_-0.4_^+0.7^M_J_ and M_2_=13.3_-0.3_^+0.4^M_J_) the boundary between stars and brown dwarfs. A conventional analysis, with scaled uncertainties for Spitzer data, implies a very-low-mass brown-dwarf binary lens at a distance of 2kpc. Compensating for systematic Spitzer errors using a Gaussian process model suggests that a higher mass M-dwarf binary at 6kpc is equally likely. A Bayesian comparison based on a galactic model favors the larger-mass solutions. We demonstrate how this degeneracy can be resolved within the next 10years through infrared adaptive-optics imaging with a 40m class telescope.2022AJ....164..102Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/164/102CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/337 : Gaia DR1 (Gaia Collaboration, 2016)J/A+A/327/1039 : Structure and evolution of low-mass stars (Chabrier+ 1997)J/AcA/50/421 : OGLE-II DIA BUL_SC1 field (Wozniak, 2000)J/ApJ/640/1051 : 25pc sample of Sun-like stars (Grether+, 2006)J/A+A/533/A134 : Abundances of microlensed stars in the Bulge (Bensby+, 2011)J/ApJS/216/7 : Planets Around Low-Mass Stars (PALMS). IV. (Bowler+, 2015)J/ApJ/814/92 : Spitzer IRAC events observed in crowded fields (Calchi+, 2015)J/AJ/154/210 : 2015 high-cadence Spitzer microlensing events (Zhu+, 2017)J/AJ/159/256 : Light curve of OGLE-2018-BLG-0677 (Herrera-Martin+, 2020)J/AJ/160/74 : Optical and IR photometry of OGLE-2017-BLG-0406 (Hirao+, 2020)J/AJ/159/262 : OGLE/KMTnet VI photometry of OGLE-2019-BLG-0551 (Mroz+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/164/102https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/164/102http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/164/102https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/164/102https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/164/102http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/164/102GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/164/102/fig6Spitzer magnification curverecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[7931/7969] Heliocentric Julian Date HJD-2450000dtime.epochdoubleFlux[56.1/90.6] Observed fluxphot.flux.density;em.optfloate_Flux[0.1/0.3] Uncertainty in Fluxstat.error;phot.fluxdoubleJ/AJ/164/102/fig1Magnification curves resulting from the fitted static binary-lens modelrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsIDObservatory identifier; OGLE or KMTNetmeta.id;instr.obstycharHJD[7885/7970] Heliocentric Julian Date HJD-2450000dtime.epochdoubleFlux[33333/275753] Observed fluxphot.flux.density;em.optdoublee_Flux[197/2964] Uncertainty in Fluxstat.error;phot.fluxdouble