J/AJ/167/64ivo://CDS.VizieR/J/AJ/167/64doi:10.26093/cds/vizier.51670064CDSBalmer W.O.Pueyo L.Lacour S.Wang J.J.Stolker T.Kammerer J.,Pourre N.Nowak M.Rickman E.Blunt S.Sivaramakrishnan A.Sing D.,Wagner K.Marleau G.-D.Lagrange A.-M.Abuter R.Amorim A.,Asensio-Torres R.Berger J.-P.Beust H.Boccaletti A.Bohn A.,Bonnefoy M.Bonnet H.Bordoni M.S.Bourdarot G.Brandner W.,Cantalloube F.Caselli P.Charnay B.Chauvin G.Chavez A.Choquet E.,Christiaens V.Clenet Y.du Foresto V.C.Cridland A.Davies R.,Dembet R.Drescher A.Duvert G.Eckart A.Eisenhauer F.,Schreiber N.M.F.Garcia P.Garcia Lopez R.Gendron E.Genzel R.,Gillessen S.Girard J.H.Grant S.Haubois X.Heissel G.Henning T.,Hinkley S.Hippler S.Houlle M.Hubert Z.Jocou L.Keppler M.,Kervella P.Kreidberg L.Kurtovic N.T.Lapeyrere V.Le Bouquin J.-B.,Lena P.Lutz D.Maire A.-L.Mang F.Merand A.Molliere P.,Mordasini C.Mouillet D.Nasedkin E.Ott T.Otten G.P.P.L.,Paladini C.Paumard T.Perraut K.Perrin G.Pfuhl O.Ribeiro D.C.,Rodet L.Rustamkulov Z.Shangguan J.Shimizu T.Straubmeier C.,Sturm E.Tacconi L.J.Vigan A.Vincent F.Ward-Duong K.Widmann F.,Winterhalder T.Woillez J.Yazici S.the GRAVITY Collaboration2024-11-06T20:20:42Z2024-05-13T11:43:34ZCDS support team

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

cds-question@unistra.frbrown-dwarfsexoplanetsinfrared-astronomyspectroscopyYoung, low-mass brown dwarfs orbiting early-type stars, with low mass ratios (q<~0.01), appear to be intrinsically rare and present a formation dilemma: could a handful of these objects be the highest-mass outcomes of "planetary" formation channels (bottom up within a protoplanetary disk), or are they more representative of the lowest-mass "failed binaries" (formed via disk fragmentation or core fragmentation)? Additionally, their orbits can yield model-independent dynamical masses, and when paired with wide wavelength coverage and accurate system age estimates, can constrain evolutionary models in a regime where the models have a wide dispersion depending on the initial conditions. We present new interferometric observations of the 16Myr substellar companion HD136164Ab (HIP75056Ab) made with the Very Large Telescope Interferometer (VLTI)/GRAVITY and an updated orbit fit including proper motion measurements from the Hipparcos-Gaia Catalog of Accelerations. We estimate a dynamical mass of 35{+/-}10MJ (q~0.02), making HD136164Ab the youngest substellar companion with a dynamical mass estimate. The new mass and newly constrained orbital eccentricity (e=0.44{+/-}0.03) and separation (22.5{+/-}1au) could indicate that the companion formed via the low-mass tail of the initial mass function. Our atmospheric fit to a SPHINX M-dwarf model grid suggests a subsolar C/O ratio of 0.45 and 3 x solar metallicity, which could indicate formation in a circumstellar disk via disk fragmentation. Either way, the revised mass estimate likely excludes bottom-up formation via core accretion in a circumstellar disk. HD136164Ab joins a select group of young substellar objects with dynamical mass estimates; epoch astrometry from future Gaia data releases will constrain the dynamical mass of this crucial object further.2024AJ....167...64Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/167/64CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/259 : The Tycho-2 Catalogue (Hog+ 2000)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/A+AS/141/371 : Low-mass stars evolution tracks & isochrones (Girardi+, 2000)J/A+A/464/581 : Sco OB2 intermediate-mass stars (Kouwenhoven+, 2007)J/AJ/144/64 : Solar neighborhood XXVIII. Substellar comp (Dieterich+, 2012)J/A+A/547/A105 : D-burning in core accretion objects (Molliere+, 2012)J/A+A/564/A125 : AGN Torus model comparison of AGN in CDFS (Buchner+, 2014)J/MNRAS/461/794 : Scorpius-Centaurus K-Type Stars (Pecaut+, 2016)J/A+A/605/L9 : NIR spectrum of exoplanet HIP 65426b (Chauvin+, 2017)J/ApJS/231/15 : Astrometric monito of ultracool dwarf binaries (Dupuy+, 2017)J/AJ/155/149 : Properties of comoving stars obs by Gaia (Bochanski+, 2018)J/ApJ/856/23 : BANYAN. XI. The BANYAN {Sigma} algorithm (Gagne+, 2018)J/AJ/155/226 : Gemini Planet Imager spectra HR8799 c/d/e (Greenbaum+, 2018)J/A+A/623/A72 : Bin of Hipparcos stars from Gaia pm anomaly (Kervella+, 2019)J/AJ/158/13 : The first 300 stars observed by the GPIES (Nielsen+, 2019)J/AJ/159/63 : AO obs of exoplanets & brown dwarf companions (Bowler+, 2020)J/A+A/633/A110 : K band spectrum of beta Pictoris b (GRAVITY+, 2020)J/AJ/160/215 : Sun neighborhood.XLVI. New M dwarf binaries (Vrijmoet+, 2020)J/ApJS/254/42 : Hipparcos-Gaia (EDR3) Catalog of Accelerations (Brandt, 2021)J/AJ/161/172 : Sun Neighborhood. XLVII. Mdwarfs with STIS (Dieterich+, 2021)J/A+A/657/A53 : Wideorbit companions to K-type stars in Sco-Cen (Bohn+, 2022)J/A+A/657/A7 : Stellar & substellar companions Gaia EDR3 (Kervella+, 2022)J/AJ/163/178 : Solar Neighborhood XLIV. M dwarfs with SOAR (Vrijmoet+, 2022)J/AJ/163/80 : The Scorpion Planet Survey; A-stars IR spectr (Wagner+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/167/64https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/167/64http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/167/64https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/167/64https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/167/64http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/167/64GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/AJ/167/64/fig4*The spectrum of HD 136164 AbrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintWave[1.02/2.43] Wavelengthumem.wlfloatFlux[5e-16/5e-15] Flux densityW.m**-2.um**-1phot.flux.density;em.IRdoublee_Flux[1e-17/4e-16]? Uncertainty in FluxW.m**-2.um**-1stat.error;phot.fluxdoublenullable