Ahrer, Eva-MariaEva-MariaAhrerStevenson, Kevin BKevin BStevensonMansfield, MeganMeganMansfieldMoran, Sarah ESarah EMoranBrande, JonathanJonathanBrandeMorello, GiuseppeGiuseppeMorelloMurray, Catriona ACatriona AMurrayNikolov, Nikolay KNikolay KNikolovPetit Dit de la Roche, Dominique J MDominique J MPetit Dit de la RocheSchlawin, EverettEverettSchlawinWheatley, Peter JPeter JWheatleyZieba, SebastianSebastianZiebaBatalha, Natasha ENatasha EBatalhaDamiano, MarioMarioDamianoGoyal, Jayesh MJayesh MGoyalLendl, MonikaMonikaLendlLothringer, Joshua DJoshua DLothringerMukherjee, SagnickSagnickMukherjeeOhno, KazumasaKazumasaOhnoBatalha, Natalie MNatalie MBatalhaBattley, Matthew PMatthew PBattleyBean, Jacob LJacob LBeanBeatty, Thomas GThomas GBeattyBenneke, BjörnBjörnBennekeBerta-Thompson, Zachory KZachory KBerta-ThompsonCarter, Aarynn LAarynn LCarterCubillos, Patricio EPatricio ECubillosDaylan, TansuTansuDaylanEspinoza, NéstorNéstorEspinozaGao, PeterPeterGaoGibson, Neale PNeale PGibsonGill, SamuelSamuelGillHarrington, JosephJosephHarringtonHu, RenyuRenyuHuKreidberg, LauraLauraKreidbergLewis, Nikole KNikole KLewisLine, Michael RMichael RLineLópez-Morales, MercedesMercedesLópez-MoralesParmentier, VivienVivienParmentierPowell, Diana KDiana KPowellSing, David KDavid KSingTsai, Shang-MinShang-MinTsaiWakeford, Hannah RHannah RWakefordWelbanks, LuisLuisWelbanksAlam, Munazza KMunazza KAlamAlderson, LiliLiliAldersonAllen, Natalie HNatalie HAllenAnderson, David RDavid RAndersonBarstow, Joanna KJoanna KBarstowBayliss, DanielDanielBaylissBell, Taylor JTaylor JBellBlecic, JasminaJasminaBlecicBryant, Edward MEdward MBryantBurleigh, Matthew RMatthew RBurleighCarone, LudmilaLudmilaCaroneCasewell, S LS LCasewellChangeat, QuentinQuentinChangeatChubb, Katy LKaty LChubbCrossfield, Ian J MIan J MCrossfieldCrouzet, NicolasNicolasCrouzetDecin, LeenLeenDecinDésert, Jean-MichelJean-MichelDésertFeinstein, Adina DAdina DFeinsteinFlagg, LauraLauraFlaggFortney, Jonathan JJonathan JFortneyGizis, John EJohn EGizisHeng, KevinKevinHengIro, NicolasNicolasIroKempton, Eliza M-REliza M-RKemptonKendrew, SarahSarahKendrewKirk, JamesJamesKirkKnutson, Heather AHeather AKnutsonKomacek, Thaddeus DThaddeus DKomacekLagage, Pierre-OlivierPierre-OlivierLagageLeconte, JérémyJérémyLeconteLustig-Yaeger, JacobJacobLustig-YaegerMacDonald, Ryan JRyan JMacDonaldMancini, LuigiLuigiManciniMay, E ME MMayMayne, N JN JMayneMiguel, YamilaYamilaMiguelMikal-Evans, ThomasThomasMikal-EvansMolaverdikhani, KaranKaranMolaverdikhaniPalle, EnricEnricPallePiaulet, CarolineCarolinePiauletRackham, Benjamin VBenjamin VRackhamRedfield, SethSethRedfieldRogers, Laura KLaura KRogersRoy, Pierre-AlexisPierre-AlexisRoyRustamkulov, ZafarZafarRustamkulovShkolnik, Evgenya LEvgenya LShkolnikSotzen, Kristin SKristin SSotzenTaylor, JakeJakeTaylorTremblin, PPTremblinTucker, Gregory SGregory STuckerTurner, Jake DJake DTurnerde Val-Borro, MiguelMiguelde Val-BorroVenot, OliviaOliviaVenotZhang, XiXiZhang2024-10-152024-10-152023-02https://boris-portal.unibe.ch/handle/20.500.12422/120320Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories. Transmission spectroscopye.g., 1,2 provides the necessary means by constraining the abundances of oxygen- and carbon-bearing species; however, this requires broad wavelength coverage, moderate spectral resolution, and high precision that, together, are not achievable with previous observatories. Now that JWST has commenced science operations, we are able to observe exoplanets at previously uncharted wavelengths and spectral resolutions. Here we report time-series observations of the transiting exoplanet WASP-39b using JWST's Near InfraRed Camera (NIRCam). The long-wavelength spectroscopic and short-wavelength photometric light curves span 2.0 - 4.0 µm, exhibit minimal systematics, and reveal well-defined molecular absorption features in the planet's spectrum. Specifically, we detect gaseous H2O in the atmosphere and place an upper limit on the abundance of CH4. The otherwise prominent CO2 feature at 2.8 µm is largely masked by H2O. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1-100× solar (i.e., an enrichment of elements heavier than helium relative to the Sun) and a sub-stellar carbon-to-oxygen (C/O) ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formatione.g., 3,4 or disequilibrium processes in the upper atmospheree.g., 5,6.en500 - Science::570 - Life sciences; biology600 - Technology::610 - Medicine & healtharticle10.48350/1771333662355110.1038/s41586-022-05590-4