J/A+A/633/A110ivo://CDS.VizieR/J/A+A/633/A110doi:10.26093/cds/vizier.36330110CDSGRAVITY CollaborationNowak M.Lacour S.Molliere P.Wang J.,Charnay B.van Dishoeck E.F.Abuter R.Amorim A.Berger J.P.Beust H.,Bonnefoy M.Bonnet H.Brandner W.Buron A.Cantalloube F.Collin C.,Chapron F.Clenet Y.Coude du Foresto V.de Zeeuw P.T.Dembet R.,Dexter J.Duvert G.Eckart A.Eisenhauer F.Forster Schreiber N.M.,Fedou P.Garcia Lopez R.Gao F.Gendron E.Genzel R.Gillessen S.,Haussmann F.Henning T.Hippler S.Hubert Z.Jocou L.Kervella P.,Lagrange A.-M.Lapeyrere V.Le Bouquin J.-B.Lena P.Maire A.-L.,Ott T.Paumard T.Paladini C.Perraut K.Perrin G.Pueyo L.Pfuhl O.,Rabien S.Rau C.Rodriguez-Coira G.Rousset G.Scheithauer S.,Shangguan J.Straub O.Straubmeier C.Sturm E.Tacconi L.J.,Vincent F.Widmann F.Wieprecht E.Wiezorrek E.Woillez J.Yazici S.,Ziegler D.2020-04-27T12:58:03Z2020-01-20T09:14:43ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsinfrared-astronomyspectroscopyBeta Pictoris is arguably one of the most studied stellar systems outside of our own. Some 30 years of observations have revealed a highly-structured circumstellar disk, with rings, belts, and a giant planet: beta Pictoris b. However very little is known about how this system came into being. Our objective is to estimate the C/O ratio in the atmosphere of {beta} Pictoris b and obtain an estimate of the dynamical mass of the planet, as well as to refine its orbital parameters using high-precision astrometry. We used the GRAVITY instrument with the four 8.2m telescopes of the Very Large Telescope Interferometer to obtain K-band spectro-interferometric data on {beta} Pic b. We extracted a medium resolution (R=500) K-band spectrum of the planet and a high- precision astrometric position. We estimated the planetary C/O ratio using two different approaches (forward modeling and free retrieval) from two different codes (ExoREM and petitRADTRANS, respectively). Finally, we used a simplified model of two formation scenarios (gravitational collapse and core-accretion) to determine which can best explain the measured C/O ratio. Our new astrometry disfavors a circular orbit for beta Pic b (e=0.15^+0.05^_-0.04_). Combined with previous results and with Hipparcos/GAIA measurements, this astrometry points to a planet mass of M=12.7+/-2.2M_{Jup}_. This value is compatible with the mass derived with the free-retrieval code petitRADTRANS using spectral data only. The forward modeling and free-retrieval approches yield very similar results regarding the atmosphere of beta Pic b. In particular, the C/O ratios derived with the two codes are identical (0.43+/-0.05 vs $0.43^+0.04^_-0.03_). We argue that if the stellar C/O in beta Pic is Solar, then this combination of a very high mass and a low C/O ratio for the planet suggests a formation through core-accretion, with strong planetesimal enrichment.2020A&A...633A.110Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/633/A110CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/542/A18 : {beta} Pic Harps radial velocity data (Lagrange+, 2012)J/A+A/607/A25 : beta Pic HARPS spectrum (Vidal-Madjar+, 2017)J/A+A/627/A28 : beta Pic BRITE, bRing, SMEI light curves (Zwintz+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/633/A110https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/633/A110http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/633/A110https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/633/A110https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/633/A110http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/633/A110GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/633/A110/list (Information on fits files)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/633/A110/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/633/A110/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/633/A110/list?GETtext/xml+votable180.050000true86.8212083-51.06651110.0055555555555555566/34054https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/633/A110?format=asciiInfrareddefaultJ/A+A/633/A110/listInformation on fits filesFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainObs.dateObservation datetime.epoch;obsnullableExt[6] Number of extensions in fits filemeta.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintJ/A+A/633/A110/spectrumbeta Pic GRAVITY spectrumrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelengthumem.wlcharFluxK-band flux1e-15W.m**-2.um**-1phot.fluxdouble