J/ApJ/899/123ivo://CDS.VizieR/J/ApJ/899/123doi:10.26093/cds/vizier.18990123CDSMeisner A.M.Faherty J.K.Kirkpatrick J.D.Schneider A.C.Caselden D.,Gagne J.Kuchner M.J.Burgasser A.J.Casewell S.L.Debes J.H.,Artigau E.Bardalez Gagliuffi D.C.Logsdon S.E.Kiman R.Allers K.,Hsu C.-C.Wisniewski J.P.Allen M.B.Beaulieu P.Colin G.DurantiniLuca H.A.Goodman S.Gramaize L.Hamlet L.K.Hinckley K.Kiwy F.,Martin D.W.Pendrill W.Rothermich A.Sainio A.Schumann J.,Andersen N.S.Tanner C.Thakur V.Thevenot M.Walla J.Wedracki Z.,Aganze C.Gerasimov R.Theissen C.2023-03-15T16:41:33Z2021-11-03T12:29:56ZCDS support team

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

cds-question@unistra.frbrown-dwarfsy-dwarfsinfrared-photometryinfrared-astronomyspectroscopyastrometryproper-motionseffective-temperatureWe present Spitzer follow-up imaging of 95 candidate extremely cold brown dwarfs discovered by the Backyard Worlds: Planet 9 citizen science project, which uses visually perceived motion in multiepoch Wide-field Infrared Survey Explorer (WISE) images to identify previously unrecognized substellar neighbors to the Sun. We measure Spitzer [3.6]-[4.5] color to phototype our brown dwarf candidates, with an emphasis on pinpointing the coldest and closest Y dwarfs within our sample. The combination of WISE and Spitzer astrometry provides quantitative confirmation of the transverse motion of 75 of our discoveries. Nine of our motion-confirmed objects have best-fit linear motions larger than 1"/yr; our fastest-moving discovery is WISEAJ155349.96+693355.2 ({mu}~2.15/yr), a possible T-type subdwarf. We also report a newly discovered wide-separation (~400au) T8 comoving companion to the white dwarf LSPMJ0055+5948 (the fourth such system to be found), plus a candidate late T companion to the white dwarf LSRJ0002+6357 at 5.5 projected separation (~8700au if associated). Among our motion-confirmed targets, five have Spitzer colors most consistent with spectral type Y. Four of these five have exceptionally red Spitzer colors suggesting types of Y1 or later, adding considerably to the small sample of known objects in this especially valuable low-temperature regime. Our Y dwarf candidates begin bridging the gap between the bulk of the Y dwarf population and the coldest known brown dwarf.2020ApJ...899..123Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/899/123CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/simbad : Simbad objects catalogue (M.Wenger 2000)II/307 : WISE Preliminary Data Release (Cutri+ 2011)II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)II/314 : UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)II/328 : AllWISE Data Release (Cutri+ 2013)II/329 : VIKING catalogue data release 1 (Edge+, 2013)II/359 : The VISTA Hemisphere Survey (VHS) catalog DR4.1 (McMahon+, 2013)II/343 : VIKING catalogue data release 2 (Edge+, 2016)I/337 : Gaia DR1 (Gaia Collaboration, 2016)II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)II/365 : The CatWISE2020 catalog (version 28-Jan-2021) (Marocco+, 2020)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/AJ/123/3409 : SDSS M, L, and T dwarfs (Hawley+, 2002)J/AJ/127/2856 : Brown dwarfs in the 2MASS Survey (Burgasser+, 2004)J/ApJ/651/502 : Spitzer IRAC photometry of M, L, and T dwarfs (Patten+, 2006)J/AJ/137/1 : Proper motions & astrometry late-type dwarfs (Faherty+, 2009)J/ApJS/197/19 : First brown dwarfs discovered by WISE (Kirkpatrick+, 2011)J/ApJS/201/19 : Hawaii Infrared Parallax Program. I. (Dupuy+, 2012)J/ApJ/753/156 : T/Y brown dwarfs with WISE photometry (Kirkpatrick+, 2012)J/AJ/145/136 : Astrometry & photometry of nearby white dwarfs (Limoges+, 2013)J/ApJ/783/122 : AllWISE motion survey (Kirkpatrick+, 2014)J/ApJ/781/4 : Photometry high proper motion objects from WISE (Luhman, 2014)J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)J/ApJS/219/19 : Census of nearby white dwarfs from SUPERBLINK (Limoges+, 2015)J/ApJS/224/36 : The AllWISE motion survey (AllWISE2) (Kirkpatrick+, 2016)J/ApJ/817/112 : NEOWISE/AllWISE high proper motion objects (Schneider+, 2016)J/ApJ/867/109 : Spitzer observations of Y and T dwarfs (Martin+, 2018)J/MNRAS/482/4570 : Gaia DR2 white dwarf candidates (Gentile Fusillo+, 2019)J/ApJS/240/19 : Parallaxes of late-T and Y dwarfs (Kirkpatrick+, 2019)J/ApJ/889/176 : Very low-mass binaries with Gaia DR2 data (Faherty+, 2020)J/ApJ/891/171 : COCONUTS. I. Spectra of a WD & T4 comoving syst. (Zhang+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/899/123https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/899/123http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/899/123https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/899/123https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/899/123http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/899/123GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/899/123/table5 (Spitzer ch2 coordinates used in linear motion fits)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/899/123/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/899/123/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/899/123/table5?GETtext/xml+votable180.050000true0.6223103763.871231230.005555555555555556Cone search capability for table J/ApJ/899/123/table6 (Linear motion fit results combining WISE and spitzer astrometry)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/899/123/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/899/123/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/899/123/table6?GETtext/xml+votable180.050000true0.622502663.87123440.005555555555555556Cone search capability for table J/ApJ/899/123/table4 (Recalibrated WISE W2 positions)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/899/123/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/899/123/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/899/123/table4?GETtext/xml+votable180.050000true0.6247569463.871146940.0055555555555555566/335 825 969 1690-1691 1761 1888 1992 2055 2108 2120 2458 2473 2558 2875 2977 3027 3066 3258 3277 3338 3409 3506 3618 3744 3924 3979 4014 5025 5208 5411 5458 5894 5905 7058 7511 7514 7583 7748 7852 7946 8168 8334 8456 9253 9287 10109 10417 10654 11479 11702 11766 12005 12057 12259 12705 12826 13168 13379 13741 13781 13835 13880 14047 14339 14509 15073 15735 15836 15957 16027 16156 16202 17253 18451 19359 19420 19436 19557 19864 19931 20007 21597 22351 22353 22758 23334 23388 23434 27043 27052 28642 31333 31715 31731 31998 32419 32485 32855 32952 33117 33274 33455 33518 33585 33674 33851 33903 34349 34456 35016 35226 35241 35707 35779 35828 35897 36041 36907 37264 37495 38109 41004 41222 42049 42981 43410 44539 44978 45178 45267 45331 45380 46357 46497 46608 46840 46972 47661 48033 48124 48557 488583.830199579824256e-20 1.6921341730348006e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/899/123?format=asciiInfrareddefaultJ/ApJ/899/123/table5Spitzer ch2 coordinates used in linear motion fitsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource designationmeta.id;meta.maincharprimaryAORSpitzer Astronomical Observation Requestmeta.code;obsintRA_ICRS[0.62/359] Right Ascension (ICRS)degpos.eq.ra;meta.mainDE_ICRS[-84/80] Declination (ICRS)degpos.eq.dec;meta.maindRA[11/78] Positional uncertainty, Right Ascensionmaspos.eq.ra;arith.diffintdDE[10/73] Positional uncertainty, Declinationmaspos.eq.dec;arith.diffintMJD[55241/58847] Modified Julian Date of observation; JD-2400000.5dtime.epochdoubleMethod[1/9] Method number (1)meta.code;obsintNcalib[4/139] Number of Gaia DR2 calibrators (2)meta.numberintJ/ApJ/899/123/table6Linear motion fit results combining WISE and spitzer astrometrySourceSource designationmeta.id;meta.mainchardof[2/12] Degrees of Freedomstat.fit.dofintchi2-n[0/5.26] Reduced {chi}^2^ statistic (1)stat.fit.chi2floatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA_ICRS[0.62/359] Right Ascension (ICRS) at Ep=MJDdegpos.eq.ra;meta.mainDE_ICRS[0.36/84] Declination (ICRS) at Ep=MJDdegpos.eq.dec;meta.maindRA[11/77] Positional uncertainty, Right Ascensionmaspos.eq.ra;arith.diffintdDE[11/71] Positional uncertainty, Declinationmaspos.eq.dec;arith.diffintMJD[55379/58806] Reference Modified Julian Date (MJD)dtime.epochdoublepmRA[-1684/1150] Proper motion, in right ascensionmas/yrpos.pm;pos.eq.rainte_pmRA[11/99] Uncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.raintpmDE[-2053/1348] Proper motion, in declinationmas/yrpos.pm;pos.eq.decinte_pmDE[10/98] Uncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decintpmTot[12/2157] Total proper motionmas/yrpos.pminte_pmTot[10/98] Uncertainty in pmTotmas/yrstat.errorintchi2-m[0.1/3447] significance of motion {chi}^2^ statisticstat.fit.goodness;phys.veloc;src.orbital.meanMotionfloatchi2[0.01/25.16] {chi}^2^ statisticstat.fit.chi2floatJ/ApJ/899/123/table4Recalibrated WISE W2 positionsRA_ICRS[0.62/359] Right Ascension (ICRS)degpos.eq.ra;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource designationmeta.id;meta.maincharDE_ICRS[-84/80] Declination (ICRS)degpos.eq.dec;meta.maindRA[95/1237] Positional uncertainty, Right Ascensionmaspos.eq.ra;arith.diffintdDE[91/1247] Positional uncertainty, Declinationmaspos.eq.dec;arith.diffintSliceTime slice (1)time.epochcharMJD[55312/58453] Mean Modified Julian Date of observation; JD-2400000.5dtime.epochdoubleJ/ApJ/899/123/table2Mid-infrared photometry from WISE and spitzerMotionMotion confirmed? (77 yes, 16 no)meta.codecharl_W1mag[>] Limit flag on W1magmeta.code.errorcharSourceSource designationmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintf_SourceDiscovery flag (1)meta.codecharW1mag[15.26/19.67]? WISE W1 3.4{mu}m magnitudemagphot.mag;em.IR.3-4umfloatnullablee_W1mag[0.03/0.6]? Uncertainty in W1magmagstat.error;phot.magfloatnullableW2mag[13.76/16.78] WISE W2 4.6{mu}m magnitudemagphot.mag;em.IR.4-8umfloate_W2mag[0.02/0.2] Uncertainty in W2magmagstat.error;phot.magfloatf_W2magFlag on W2mag (2)meta.codecharl_W1-W2[>] Limit flag on W1-W2meta.code.errorcharW1-W2[0.17/3.75]? WISE W1-W2 colormagphot.color;em.IR;em.IRfloatnullablee_W1-W2[0.04/0.6]? Uncertainty for W1-W2magstat.errorfloatnullableAORSpitzer Astronomical Observation Requestmeta.code;obsint3.6mag[15.08/19.1]? Spitzer/IRAC 3.6{mu}m band magnitudemagphot.mag;em.IR.3-4umfloatnullablee_3.6mag[0.01/0.3]? Uncertainty in 3.6magmagstat.errorfloatnullable4.5mag[13.95/16.79] Spitzer/IRAC 4.5{mu}m band magnitudemagphot.mag;em.IR.4-8umfloate_4.5mag[0.01/0.06] Uncertainty in 4.5magmagstat.errorfloat3.6-4.5[0.002/3.26]? Spitzer [3.6-4.5] colormagphot.color;em.IR;em.IRfloatnullablee_3.6-4.5[0.02/0.3]? Uncertainty in 3.6-4.5magstat.errorfloatnullableRef[1/6] WISE photometry reference (3)meta.refintJ/ApJ/899/123/table7Ground-based NIR photometry from the VISTA/UKIRT archives and OMM follow-up for motion-confirmed members of our sampleSourceSource designationmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintl_Ymag[>] Limit flag for Ymag (1)meta.code.error;pos.cartesian.ycharYmag[18.48/20.5]? Y band magnitudemagphot.mag;em.IR.Jfloatnullablee_Ymag[0.02/0.3]? Uncertainty in Ymagmagstat.error;phot.magfloatnullablel_Jmag[>] Limit flag for Jmag (1)meta.code.errorcharJmag[16.07/20.36] MKO J band magnitudemagphot.mag;em.IR.Jfloate_Jmag[0/0.7]? Uncertainty in Jmagmagstat.error;phot.magfloatnullablel_Hmag[>] Limit flag for Hmag (1)meta.code.errorcharHmag[17.86/19.51]? MKO H band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag[0.03/0.2]? Uncertainty in Hmagmagstat.error;phot.magfloatnullableKmag[18.2/18.2]? MKO K band magnitudemagphot.mag;em.IR.Kfloatnullablee_Kmag[0.1/0.2]? Uncertainty in Kmagmagstat.error;phot.magfloatnullablel_Ksmag[>] Limit flag for Ksmag (1)meta.code.errorcharKsmag[17.38/18.89]? K_s_ band magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag[0.05/0.3]? Uncertainty in Ksmagmagstat.error;phot.magfloatnullableInstrInstrument used (2)instr.setupcharJ/ApJ/899/123/table8Additional OMM J band photometrySourceSource designationmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintl_Jmag[>] Limit flag for Jmagmeta.code.errorcharJmag[15.73/19.82] MKO J band magnitude (1)magphot.mag;em.IR.Jfloate_Jmag[0.05/0.9]? Uncertainty in Jmagmagstat.error;phot.magfloatnullablef_Jmag[a] Flag(s) on Jmag (2)meta.codecharJ/ApJ/899/123/table9Derived parameters of motion-confirmed objects with Spitzer 3.6um and 4.5um photometrySourceSource designationmeta.id;meta.mainchare_4.5MAG[0.2/0.6] lower error on Mch2magstat.errorfloatDist[7.1/42.9] Photometric distance estimatepcpos.distancefloatE_Dist[1.4/6.4] upper error on Distpcstat.error;stat.maxfloate_Dist[1.2/5.6] lower error on Distpcstat.errorfloatTeff[303/1006]? Effective temperatureKphys.temperature.effectiveintnullableE_Teff[82/132]? upper error on TeffKstat.error;stat.maxintnullablee_Teff[82/124]? lower error on TeffKstat.error;phys.temperature.effectiveintnullableHch2[16.23/22.42] Spitzer/IRAC 4.5um reduced proper motion; H_ch2_=m_ch2_+5log_10_({mu})+5magpos.pmfloatE_Hch2[0.04/0.47] upper error on Hch2magstat.error;stat.maxfloate_Hch2[0.04/0.39] lower error on Hch2magstat.errorfloatVtan[13/395] Tangential velocitykm/sphys.veloc.transverseintE_Vtan[3/48] upper error on Vtankm/sstat.error;stat.maxinte_Vtan[3/44] lower error on Vtankm/sstat.errorintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintf_SourceSource flag (1)meta.codecharl_SphT[>=] Limit flag on SphTmeta.code.errorcharSphT[5/11] Spectral "phototype" (2)src.spTypefloat4.5MAG[12.53/16.19] Spitzer/IRAC 4.5um absolute magnitudemagphys.magAbsfloatE_4.5MAG[0.2/0.6] upper error on Mch2magstat.error;stat.maxfloatJ/ApJ/899/123/table3Details on spectroscopic follow-UpNf[3/12] Number of nod framesmeta.numberintStdTelluric standard starmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource designationmeta.id;meta.maincharf_SourceSource flag (1)meta.codecharTelTelescope; Baade or Keck IImeta.id;instr.telcharInstrInstrumentmeta.id;instrcharObsDay of observationtime.epochTexp[120/300] Exposure timestime.duration;obs.exposureintCondConditions; Clear or Poormeta.notecharSpTSpectral Typesrc.spTypecharJ/ApJ/899/123/table1Targets without any spitzer counterpartrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAORSpitzer Astronomical Observation Requestmeta.code;obsintSourceSource designation (1)meta.id;meta.maincharW2mag[16.14/16.49] WISE W2 4.6{mu}m magnitudemagphot.mag;em.IR.4-8umfloate_W2mag[0.12/0.2] Uncertainty in W2magmagstat.error;phot.magfloat