J/A+A/546/L3ivo://CDS.VizieR/J/A+A/546/L3doi:10.26093/cds/vizier.35469003CDSCatalan S.Tremblay P.-E.Pinfield D.J.Smith L.C.Zhang Z.H.,Napiwotzki R.Marocco F.Day-Jones A.C.Gomes J.Forde K.P.,Lucas P. W.Jones H.R.A.2017-06-13T11:09:00Z2012-10-01T08:19:45ZCDS support team

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

cds-question@unistra.frwhite-dwarf-starsinfrared-astronomyspectroscopyWe report the identification of LSR J0745+2627 in the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) as a cool white dwarf with kinematics and age compatible with the thick-disk/halo population. LSR J0745+2627 has a high proper motion (890mas/yr) and a high reduced proper motion value in the J band (H_J=21.87). We show how the infrared-reduced proper motion diagram is useful for selecting a sample of cool white dwarfs with low contamination. LSR J0745+2627 is also detected in the Sloan Digital Sky Survey (SDSS) and the Wide-field Infrared Survey Explorer (WISE). We have spectroscopically confirmed this object as a cool white dwarf using X-Shooter on the Very Large Telescope. An analysis of its spectral energy distribution reveals that its atmosphere is compatible with a pure-H composition model with an effective temperature of 3880+/-90K. This object is the brightest pure-H ultracool white dwarf (Teff<4000K) ever identified. We have constrained the distance (24-45pc), space velocities and age considering different surface gravities. The results obtained suggest that LSR J0745+2627 belongs to the thick-disk/halo population and is also one of the closest ultracool white dwarfs.2012A&A...546L...3Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/546/L3CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/546/L3https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/546/L3http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/546/L3https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/546/L3https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/546/L3http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/546/L3GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/A+A/546/L3/tableSpectrum of LSR J0745+2627recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[3098/24759] Wavelength0.1nmem.wlfloatFluxFlux (in erg/cm^2^/s/{AA})cW.m**-2.nm**-1phot.fluxdoublee_FluxFlux errorcW.m**-2.nm**-1stat.error;phot.fluxdouble