J/ApJ/889/176ivo://CDS.VizieR/J/ApJ/889/176doi:10.26093/cds/vizier.18890176CDSFaherty J.K.Goodman S.Caselden D.Colin G.Kuchner M.J.Meisner A.M.,Gagne J.Schneider A.C.Gonzales E.C.Bardalez Gagliuffi D.C.,Logsdon S.E.Allers K.Burgasser A.J.2022-10-25T07:13:36Z2021-08-11T09:53:35ZCDS support team

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

cds-question@unistra.frbrown-dwarfsmultiple-starsstellar-spectral-typesstellar-massesproper-motionsWe report the discovery of WISE 2150-7520AB (W2150AB): a widely separated (~341au) very low-mass L1+T8 co-moving system. The system consists of the previously known L1 primary 2MASS J21501592-7520367 and a newly discovered T8 secondary found at position 21:50:18.99-75:20:54.6 (MJD=57947) using Wide-field Infrared Survey Explorer data via the Backyard Worlds: Planet 9 citizen science project. We present Spitzer ch1 and ch2 photometry (ch1-ch2=1.41+/-0.04mag) of the secondary and Folded-port InfraRed Echellette prism spectra of both components. The sources show no peculiar spectral or photometric signatures, indicating that each component is likely field age. Using all observed data and the Gaia DR2 parallax of 41.3593+/-0.2799mas for W2150A we deduce fundamental parameters of log(L_bol_/L_{sun}_)=-3.69+/-0.01, Teff=2118+/-62K, and an estimated mass=72+/-12M_Jup_ for the L1 and log(L_bol_/L_{sun}_)=-5.64+/-0.02, Teff=719+/-61K, and an estimated mass=34+/-22M_Jup_ for the T8. At a physical separation of ~341au this system has E_bin_=10^41^erg, making it the lowest binding energy system of any pair with M_tot_<0.1M_{sun}_ not associated with a young cluster. It is equivalent in estimated mass ratio, E_bin_, and physical separation to the ~2Myr M7.25+M8.25 binary brown dwarf 2MASS J11011926-7732383AB (2M1101AB) found in the Chameleon star-forming region. W2150AB is the widest companion system yet observed in the field where the primary is an L dwarf or later.2020ApJ...889..176Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/889/176CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)I/345 : Gaia DR2 (Gaia Collaboration, 2018)II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)J/AJ/126/1526 : IR photometry of ultracool dwarfs (Bouy+, 2003)J/AJ/125/3302 : HST binary very low mass stars & brown dwarfs (Gizis+, 2003)J/AJ/127/2856 : Brown dwarfs in the 2MASS Survey (Burgasser+, 2004)J/A+A/435/363 : Southern Infrared Proper Motion Survey (Deacon+, 2005)J/AJ/132/891 : Binaries among nearby L dwarfs (Reid+, 2006)J/ApJ/667/520 : Proper motions in multiple systems (Caballero, 2007)J/MNRAS/390/1517 : Proper motions of field L and T dwarfs (Casewell+, 2008)J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)J/AJ/136/1290 : Ultracool dwarfs from the 2MASS (Reid+, 2008)J/AJ/137/1 : PMs and astrometry of late-type dwarfs (Faherty+, 2009)J/ApJ/710/1142 : SpeX spectros. of low mass binaries. I. (Burgasser+, 2010)J/ApJS/190/100 : NIR proper motion survey using 2MASS (Kirkpatrick+, 2010)J/ApJ/710/1627 : Mid-IR photometry of cold brown dwarfs (Leggett+, 2010)J/MNRAS/404/1817 : 2MASS/SDSS data for 806 ultracool dwarfs (Zhang+, 2010)J/A+A/529/A102 : MOA-2007-BLG-387Lb light curve I band (Batista+, 2011)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/752/56 : BDKP. III. Parallaxes for ultracool dwarfs (Faherty+, 2012)J/MNRAS/433/457 : 76 T dwarfs from the UKIDSS LAS (Burningham+, 2013)J/MNRAS/430/1171 : Sub-stellar birth rate from UKIDSS (Day-Jones+, 2013)J/A+A/556/A133 : Astrometric orbit of DENIS J082303.1-49120 (Sahlmann+, 2013)J/ApJ/794/143 : New SpeX Observations of M7-L6 Dwarfs (Bardalez+, 2014)J/ApJ/792/119 : Companions to nearby stars from Pan-STARRS 1 (Deacon+, 2014)J/ApJ/783/122 : AllWISE motion survey (Kirkpatrick+, 2014)J/ApJ/810/158 : M,L,T dwarfs parameters and SEDs (Filippazzo+, 2015)J/other/Sci/350.64 : 51 Eri b near-infrared spectrum (Macintosh+, 2015)J/MNRAS/449/3651 : L and T dwarfs from UKIDSS LAS (Marocco+, 2015)J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)J/ApJS/224/36 : The AllWISE motion survey (AllWISE2) (Kirkpatrick+, 2016)J/ApJ/833/96 : Hawaii infrared plx prog. II. Ultracool dwarfs (Liu+, 2016)J/ApJS/231/15 : Astrometric monitoring of dwarf binaries (Dupuy+, 2017)J/ApJ/842/118 : BDs with spectral type later than T6 (Leggett+, 2017)J/ApJ/856/23 : BANYAN. XI. The BANYAN {Sigma} algorithm (Gagne+, 2018)J/ApJS/240/19 : Parallaxes of late-T and Y dwarfs (Kirkpatrick+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/889/176https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/889/176http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/889/176https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/889/176https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/889/176http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/889/176GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/889/176/table2 (Companion systems with total mass <0.2M_Sun_ (System properties))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/889/176/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/889/176/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/889/176/table2?GETtext/xml+votable180.050000true65.897416725.05083330.005555555555555556Cone search capability for table J/ApJ/889/176/table3 (Companion systems with total mass <0.2M_Sun_ (Dynamics))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/889/176/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/889/176/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/889/176/table3?GETtext/xml+votable180.050000true65.897458325.050750.0055555555555555566/223 342 461 463 466 496 550 826 1050 1054 1063 1075 1765 2083 2789 3406 4116 4253 4316 4672 4775 4875 4946 5077 5200 5317 5413 5540 5560 5659 6199 6328 6629 6750 7291 7592 7668 8223 8371 8384 8422 8440 8475 8478 8495 8522 8719 8735 8901 8995 9063 9124 9136 9322 9508 9534 9569 9588 10072 10195 10475 10760 10849 11164 11257 11450 11834 12211 12541 12570 12579 12600 13736 15255 16053 16226 16502 17075 17259 17776 18025 18711 18789 18858 18866 18933 19050 19144 19200 19369 19515 19761 19895 20326 20993 21438 21660 22759 23234 23503 24580 24694 25015 25055 25223 25310 25443 25623 26430 26594 26761 26861 26886 27332 27618 27653 28040 28211 28277 28728 29305 31009 31035 31309 31419 31520 32457 32643 34119 34400 34622 35024 35063 35106 35268 35471 35499 36602 36640 36821 36956 37573 38039 38683 38786 39185 40297 40397 42635 42983 43413 43856 43875 43957 43966 44118 44311 44360 44402 44954 45053 45178 45564 45752 46138 47012 47825 48300 48462 48907 489951.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/889/176?format=asciidefaultJ/ApJ/889/176/table2Companion systems with total mass <0.2M_Sun_ (System properties)SimbadNameName of the primary in SIMBAD (based on coordinates or system ID)meta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSystem Name (1)meta.idcharprimaryRAJ2000Hour of Right Ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000) (2)pos.eq.dec;meta.mainSpT1Spectral Type, Method 1src.spTypecharSpT2Spectral Type, Method 2src.spTypecharMass1[0.017/0.19] Companion mass, Method 1 (3)solMassphys.massfloatMass2[0.003/0.12] Companion mass, Method 2 (3)solMassphys.massfloatMtot[0.028/0.25] Total masssolMassphys.massfloatq[0.01/1.63] Mass Ratiophys.massfloatSep[0.03/6700] Separationaupos.distance;src.orbitalfloatEbin[0.17/22012] Binding energy in 10^41^erg units (4)1e+34Jphys.energydoubleYng?Young source? (5)meta.codecharRefReference (see refs.dat)meta.ref;pos.frameintFlagFlag on sources of dynamical/total masses (6)meta.code.errorcharJ/ApJ/889/176/table3Companion systems with total mass <0.2M_Sun_ (Dynamics)IDSystem Namemeta.idcharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000? Hour of Right Ascension, Primary (J2000)pos.eq.ra;meta.mainnullableDEJ2000? Degree of Declination, Primary (J2000)pos.eq.dec;meta.mainnullablePlx1[5.4/250]? Gaia DR2 primary parallaxmaspos.parallax.trigdoublenullablee_Plx1[0.04/4]? Uncertainty in Plx1masstat.errorfloatnullablepmRA1[-778/2585]? Gaia DR2 proper motion in RA, Primarymas/yrpos.pm;pos.eq.radoublenullablee_pmRA1[0.07/3.5]? Uncertainty in pmRA1mas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE1[-1506/825]? Gaia DR2 proper motion in DEC, Primarymas/yrpos.pm;pos.eq.decdoublenullablee_pmDE1[0.05/2.7]? Uncertainty in pmDE1mas/yrstat.error;pos.pm;pos.eq.decfloatnullableGmag1[5.7/21.2]? Gaia DR2 G band magnitude, Primarymagphot.mag;em.optfloatnullableRA2? Hour of Right Ascension, Secondary (J2000)pos.eq.ranullableDE2? Degree of Declination, Secondary (J2000)pos.eq.decnullablePlx2[5.4/82.1]? Gaia DR2 secondary parallaxmaspos.parallax.trigfloatnullablee_Plx2[0.14/1.6]? Uncertainty in Plx2masstat.errorfloatnullablepmRA2[-644/672]? Gaia DR2 proper motion in RA, Secondarymas/yrpos.pm;pos.eq.radoublenullablee_pmRA2[0.2/4.1]? Uncertainty in pmRA2mas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE2[-1499/80]? Gaia DR2 proper motion in DEC, Secondarymas/yrpos.pm;pos.eq.decdoublenullablee_pmDE2[0.17/3.3]? Uncertainty in pmDE2mas/yrstat.error;pos.pm;pos.eq.decfloatnullableGmag2[16.4/21]? Gaia DR2 G band magnitude, Secondarymagphot.mag;em.optfloatnullableJ/ApJ/889/176/refsReferencesRefReference codemeta.note;meta.mainintprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBibCodeBibcode of the referencemeta.bib.bibcodecharAuthFirst author's namemeta.bib.authorcharCommCommentmeta.notechar