J/ApJ/946/L6ivo://CDS.VizieR/J/ApJ/946/L6doi:10.26093/cds/vizier.19469006CDSMiles B.E.Biller B.A.Patapis P.Worthen K.Rickman E.Hoch K.K.W.,Skemer A.Perrin M.D.Whiteford N.Chen C.H.Sargent B.Mukherjee S.,Morley C.V.Moran S.E.Bonnefoy M.Petrus S.Carter A.L.Choquet E.,Hinkley S.Ward-Duong K.Leisenring J.M.Millar-Blanchaer M.A.,Pueyo L.Ray S.Sallum S.Stapelfeldt K.R.Stone J.M.Wang J.J.,Absil O.Balmer W.O.Boccaletti A.Bonavita M.Booth M.Bowler B.P.,Chauvin G.Christiaens V.Currie T.Danielski C.Fortney J.J.,Girard J.H.Grady C.A.Greenbaum A.Z.Henning T.Hines D.C.,Janson M.Kalas P.Kammerer J.Kennedy G.M.Kenworthy M.A.,Kervella P.Lagage P.-O.Lew B.W.P.Liu M.C.Macintosh B.Marino S.,Marley M.S.Marois C.Matthews E.C.Matthews B.C.Mawet D.,McElwain M.W.Metchev S.Meyer M.R.Molliere P.Pantin E.,Quirrenbach A.Rebollido I.Ren B.B.Schneider G.Vasist M.,Wyatt M.C.Zhou Y.Briesemeister Z.W.Bryan M.L.Calissendorff P.,Cantalloube F.Cugno G.De Furio M.Dupuy T.J.Factor S.M.,Faherty J.K.Fitzgerald M.P.Franson K.Gonzales E.C.Hood C.E.,Howe A.R.Kraus A.L.Kuzuhara M.Lagrange A.-M.Lawson K.Lazzoni C.,Liu P.Llop-Sayson J.Lloyd J.P.Martinez R.A.Mazoyer J.Quanz S.P.,Redai J.A.Samland M.Schlieder J.E.Tamura M.Tan X.Uyama T.,Vigan A.Vos J.M.Wagner K.Wolff S.G.Ygouf M.Zhang XiZhang K.,Zhang Z.2025-06-02T07:05:25Z2025-04-09T15:14:16ZCDS support team

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

cds-question@unistra.frbrown-dwarfsinfrared-astronomyspectroscopymultiple-starsWe present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a <20M_Jup_ widely separated (~8", a=150au), young, planetary-mass companion that shares photometric colors and spectroscopic features with the directly imaged exoplanets HR 8799c, d, and e. As an L-to-T transition object, VHS 1256 b exists along the region of the color-magnitude diagram where substellar atmospheres transition from cloudy to clear. We observed VHS 1256 b with JWST's NIRSpec IFU and MIRI MRS modes for coverage from 1 to 20{mu}m at resolutions of ~1000-3700. Water, methane, carbon monoxide, carbon dioxide, sodium, and potassium are observed in several portions of the JWST spectrum based on comparisons from template brown dwarf spectra, molecular opacities, and atmospheric models. The spectral shape of VHS1256b is influenced by disequilibrium chemistry and clouds. We directly detect silicate clouds, the first such detection reported for a planetary-mass companion.2023ApJ...946L...6Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/946/L6CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/350 : Gaia EDR3 (Gaia Collaboration, 2020)J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)J/ApJ/651/502 : Spitzer IRAC phot. of M, L, and T dwarfs (Patten+, 2006)J/ApJS/201/19 : Hawaii Infrared Parallax Program. I. (Dupuy+, 2012)J/ApJ/810/158 : M,L,T dwarfs fundamental param. and SEDs (Filippazzo+, 2015)J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)J/ApJ/833/96 : Hawaii infrared plx prog. II. Ultracool dwarfs (Liu+, 2016)J/ApJS/234/1 : Cat. of M, L, & T dwarfs from PS1 3{pi} Survey (Best+, 2018)J/AJ/161/42 : Volume-limited sample of cool dwarfs. I. L0-T8 (Best+, 2021)J/AJ/164/155 : K-band sp. of substellar companion VHS1256b (Hoch+, 2022)J/MNRAS/513/5701 : Silicate clouds in ultracool dwarfs (Suarez+, 2022)J/AJ/164/239 : IR LC of VHS1256-1257b in 2018 & 2020 epochs (Zhou+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/946/L6https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/946/L6http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/946/L6https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/946/L6https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/946/L6http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/946/L6GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/ApJ/946/L6/spJWST spectrum of VHS 1256 b (Data behind Figure 8)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[0.96/19.8] Wavelengthumem.wl;em.IRdoubleFlux[1.94e-18/8.62e-16]? FluxW.m**-2.um**-1phot.flux;em.IRdoublenullablee_Flux[7.41e-19/1.46e-17]? Uncertainty in FluxW.m**-2.um**-1stat.error;phot.flux;em.IRdoublenullableModeJWST Observing Mode (1)instr.setupcharJ/ApJ/946/L6/modelBest fit model atmospheric model (Data behind Figure 8)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[0.5/20] Wavelengthumem.wl;em.IRdoubleFlux[1.83e-24/6.11e-16] FluxW.m**-2.um**-1phot.flux;em.IRdouble