Early Release Science of the exoplanet WASP-39b with JWST NIRCam.
Creators: name: Ahrer, Eva-Maria
name: Stevenson, Kevin B
name: Mansfield, Megan
name: Moran, Sarah E
name: Brande, Jonathan
name: Morello, Giuseppe
name: Murray, Catriona A
name: Nikolov, Nikolay K
name: Petit Dit De La Roche, Dominique JM
name: Schlawin, Everett
name: Wheatley, Peter J
name: Zieba, Sebastian
name: Batalha, Natasha E
name: Damiano, Mario
name: Goyal, Jayesh M
name: Lendl, Monika
name: Lothringer, Joshua D
name: Mukherjee, Sagnick
name: Ohno, Kazumasa
name: Batalha, Natalie M
name: Battley, Matthew P
name: Bean, Jacob L
name: Beatty, Thomas G
name: Benneke, Björn
name: Berta-Thompson, Zachory K
name: Carter, Aarynn L
name: Cubillos, Patricio E
name: Daylan, Tansu
name: Espinoza, Néstor
name: Gao, Peter
name: Gibson, Neale P
name: Gill, Samuel
name: Harrington, Joseph
name: Hu, Renyu
name: Kreidberg, Laura
name: Lewis, Nikole K
name: Line, Michael R
name: López-Morales, Mercedes
name: Parmentier, Vivien
name: Powell, Diana K
name: Sing, David K
name: Tsai, Shang-Min
name: Wakeford, Hannah R
name: Welbanks, Luis
name: Alam, Munazza K
name: Alderson, Lili
name: Allen, Natalie H
name: Anderson, David R
name: Barstow, Joanna K
name: Bayliss, Daniel
name: Bell, Taylor J
name: Blecic, Jasmina
name: Bryant, Edward M
name: Burleigh, Matthew R
name: Carone, Ludmila
name: Casewell, SL
name: Changeat, Quentin
name: Chubb, Katy L
name: Crossfield, Ian JM
name: Crouzet, Nicolas
name: Decin, Leen
name: Désert, Jean-Michel
name: Feinstein, Adina D
name: Flagg, Laura
name: Fortney, Jonathan J
name: Gizis, John E
name: Heng, Kevin
name: Iro, Nicolas
name: Kempton, Eliza M-R
name: Kendrew, Sarah
name: Kirk, James
name: Knutson, Heather A
name: Komacek, Thaddeus D
name: Lagage, Pierre-Olivier
name: Leconte, Jérémy
name: Lustig-Yaeger, Jacob
name: MacDonald, Ryan J
name: Mancini, Luigi
name: May, EM
name: Mayne, NJ
name: Miguel, Yamila
name: Mikal-Evans, Thomas
name: Molaverdikhani, Karan
name: Palle, Enric
name: Piaulet, Caroline
name: Rackham, Benjamin V
name: Redfield, Seth
name: Rogers, Laura K
name: Roy, Pierre-Alexis
name: Rustamkulov, Zafar
name: Shkolnik, Evgenya L
name: Sotzen, Kristin S
name: Taylor, Jake
name: Tremblin, P
name: Tucker, Gregory S
name: Turner, Jake D
name: De Val-Borro, Miguel
name: Venot, Olivia
name: Zhang, Xi
Publisher: name: Apollo - University of Cambridge Repository
Year: 2023
Subjects: Article
/639/33/34/862
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article

description: Measuring 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 spectroscopy (for example, refs. 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, which, 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 micrometres, exhibit minimal systematics and reveal well defined molecular absorption features in the planet's spectrum. Specifically, we detect gaseous water in the atmosphere and place an upper limit on the abundance of methane. The otherwise prominent carbon dioxide feature at 2.8 micrometres is largely masked by water. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1-100-times solar (that is, an enrichment of elements heavier than helium relative to the Sun) and a substellar C/O ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formation (for example, refs. 3,4,) or disequilibrium processes in the upper atmosphere (for example, refs. 5,6).