J/AJ/166/181ivo://CDS.VizieR/J/AJ/166/181doi:10.26093/cds/vizier.51660181CDSYoshida S.Vissapragada S.Latham D.W.Bieryla A.Thorngren D.P.,Eastman J.D.Lopez-Morales M.Barkaoui K.Beichman C.Berlind P.,Buchave L.A.Calkins M.L.Ciardi D.R.Collins K.A.Cosentino R.,Crossfield I.J.M.Dai F.DiTomasso V.Dowling N.Esquerdo G.A.,Fores-Toribio R.Ghedina A.Goliguzova M.V.Golub E.Gonzales E.J.,Horta F.G.Higuera J.Hoch N.Horne K.Howell S.B.Jenkins J.M.,Klusmeyer J.Laloum D.Lissauer J.J.Logsdon S.E.Malavolta L.,Matson R.A.Matthews E.C.McLeod K.K.Medina J.V.Munoz J.A.,Osborn H.P.Safonov B.Schlieder J.Schmidt M.Schweiker H.,Seager S.Sozzetti A.Srdoc G.Stefansson G.Strakhov I.A.,Striegel S.Villasenor J.Winn J.N.2024-11-06T20:18:06Z2024-04-24T08:11:23ZCDS support team

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

cds-question@unistra.frexoplanetsg-starsvisible-astronomyspectroscopyradial-velocityWe present the discovery of TOI-1420b, an exceptionally low-density ({rho}=0.08{+/-}0.02g/cm^3^) transiting planet in a P=6.96days orbit around a late G-dwarf star. Using transit observations from TESS, LCOGT, Observatoire Prive du Mont, Whitin, Wendelstein, OAUV, Ca l'Ou, and KeplerCam, along with radial velocity observations from HARPS-N and NEID, we find that the planet has a radius of Rp=11.9{+/-}0.3R{Earth} and a mass of Mp=25.1{+/-}3.8M{Earth}. TOI-1420b is the largest known planet with a mass less than 50M{Earth}, indicating that it contains a sizeable envelope of hydrogen and helium. We determine TOI-1420b's envelope mass fraction to be f~=82_-6_^+7^% , suggesting that runaway gas accretion occurred when its core was at most four to five times the mass of the Earth. TOI-1420b is similar to the planet WASP-107b in mass, radius, density, and orbital period, so a comparison of these two systems may help reveal the origins of close-in low-density planets. With an atmospheric scale height of 1950km, a transmission spectroscopy metric of 580, and a predicted Rossiter-McLaughlin amplitude of about 17m/s, TOI-1420b is an excellent target for future atmospheric and dynamical characterization.2023AJ....166..181Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/166/181CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/259 : The Tycho-2 Catalogue (Hog+ 2000)J/ApJ/757/18 : Radial velocities 16 hot Jupiter host stars (Albrecht+, 2012)J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/ApJ/831/64 : Mass-metallicity relation for giant planets (Thorngren+, 2016)J/A+A/599/A3 : WASP 127, 136 and 138 RV and light curves (Lam+, 2017)J/AJ/153/215 : Photometry and spectroscopy of KELT-11 (Pepper+, 2017)J/AJ/153/142 : Radial velocities systems hosting sub-Saturns (Petigura+, 2017)J/AJ/155/89 : California-Kepler Survey (CKS). IV. Planets (Petigura+, 2018)J/AJ/156/102 : TESS Input Catalog and Candidate Target List (Stassun+, 2018)J/ApJ/874/L31 : Giant planet bulk & atmosphere metallicities (Thorngren+, 2019)J/ApJS/254/39 : Exoplanet candidates from TESS first 2yr obs (Guerrero+, 2021)J/AJ/161/70 : RVvel for WASP-107 with HIRES & CORALIE (Piaulet+, 2021)J/AJ/161/119 : The TESS-Keck survey. IV. Rvel for WASP-107 (Rubenzahl+, 2021)J/ApJS/258/16 : TESS Eclipsing Binary stars. I. Sectors 1-26 (Prsa+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/166/181https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/166/181http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/166/181https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/166/181https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/166/181http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/166/181GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/166/181/table3TOI-1420 radial velocity measurements from HARPS-N and NEIDrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrument identifiermeta.id;instrcharBJD[2459513/2459829] Barycentric Julian Date; TDBdtime.epochdoubleRVel[-10354/-10228] Radial velocitym/sspect.dopplerVelocdoublee_RVel[1/8] Uncertainty in RVelm/sstat.error;spect.dopplerVelocfloat