J/A+A/581/A73ivo://CDS.VizieR/J/A+A/581/A73doi:10.26093/cds/vizier.35810073CDSLodieu N.Zapatero Osorio M.R.Rebolo R.Bejar V.J.S.Pavlenko Y.,Perez-Garrido A.2017-06-26T11:49:20Z2015-09-07T08:32:31ZCDS support team

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

cds-question@unistra.frmultiple-starslate-type-starsspectroscopyWe obtained high signal-to-noise intermediate-resolution (R~6000-11000) optical (600-1000nm) and near-infrared (1000-2480nm) spectra of each component of the the closest brown dwarf binary, Luhman 16AB, with X-Shooter on the Very Large Telescope (VLT). We classify the primary and secondary as L6-L7.5 and T0+/-1, respectively, in agreement with previous measurements. We present measurements of the lithium pseudo-equivalent widths, which appears of similar strength on both components. The presence of lithium (^7^Li) in both components imply masses below 0.06M_{sun} while comparison with models suggests lower limits of 0.04M_{sun}. The detection of lithium in the T component is the first of its kind. Similarly, we assess the strength of other alkali lines (e.g. 6-7{AA} for RbI and 4-7{AA} for CsI features) and compare them with estimates for L and T dwarfs. We also derive effective temperatures and luminosities of each component of the binary (-4.66dex, 1305K) and (-4.68dex, 1320K) for the L and T dwarf, respectively. Using our radial velocity determinations, the binary does not appear to belong to any of the well-known moving group. Our preliminary theoretical analysis of the optical and J-band spectra indicates that the L- and T-type spectra can be reproduced with a single temperature and gravity but different relative chemical abundances which impact strongly the spectral energy distribution of L/T transition objects.2015A&A...581A..73Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/581/A73CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/581/A73https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/581/A73http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/581/A73https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/581/A73https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/581/A73http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/581/A73GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/581/A73/spluh16aVLT/X-shooter spectrum of Luhman16ArecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLambdaWavelength in nmnmem.wldoubleFluxFlux in ergs/cm^2^/s/{AA}10mW.m**-2.nm**-1phot.fluxdoubleJ/A+A/581/A73/spluh16bVLT/X-shooter spectrum of Luhman16BrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLambdaWavelength in nmnmem.wldoubleFluxFlux in ergs/cm^2^/s/{AA}10mW.m**-2.nm**-1phot.fluxdouble