Early Release Science of the exoplanet WASP-39b with JWST NIRISS
Creators: name: Feinstein, Adina D.
name: Radica, Michael
name: Welbanks, Luis
name: Murray, Catriona Anne
name: Ohno, Kazumasa
name: Coulombe, Louis-Philippe
name: Espinoza, Néstor
name: Bean, Jacob L.
name: Teske, Johanna K.
name: Benneke, Björn
name: Line, Michael R.
name: Rustamkulov, Zafar
name: Saba, Arianna
name: Tsiaras, Angelos
name: Barstow, Joanna K.
name: Fortney, Jonathan J.
name: Gao, Peter
name: Knutson, Heather A.
name: MacDonald, Ryan J.
name: Mikal-Evans, Thomas
name: Rackham, Benjamin V.
name: Taylor, Jake
name: Parmentier, Vivien
name: Batalha, Natalie M.
name: Berta-Thompson, Zachory K.
name: Carter, Aarynn L.
name: Changeat, Quentin
name: Dos Santos, Leonardo A.
name: Gibson, Neale P.
name: Goyal, Jayesh M.
name: Kreidberg, Laura
name: López-Morales, Mercedes
name: Lothringer, Joshua D.
name: Miguel, Yamila
name: Molaverdikhani, Karan
name: Moran, Sarah E.
name: Morello, Giuseppe
name: Mukherjee, Sagnick
name: Sing, David K.
name: Stevenson, Kevin B.
name: Wakeford, Hannah R.
name: Ahrer, Eva-Maria
name: Alam, Munazza K.
name: Alderson, Lili
name: Allen, Natalie H.
name: Batalha, Natasha E.
name: Bell, Taylor J.
name: Blecic, Jasmina
name: Brande, Jonathan
name: Caceres, Claudio
name: Casewell, S. L.
name: Chubb, Katy L.
name: Crossfield, Ian J. M.
name: Crouzet, Nicolas
name: Cubillos, Patricio E.
name: Decin, Leen
name: Désert, Jean-Michel
name: Harrington, Joseph
name: Heng, Kevin
name: Henning, Thomas
name: Iro, Nicolas
name: Kempton, Eliza M.-R.
name: Kendrew, Sarah
name: Kirk, James
name: Krick, Jessica
name: Lagage, Pierre-Olivier
name: Lendl, Monika
name: Mancini, Luigi
name: Mansfield, Megan
name: May, E. M.
name: Mayne, N. J.
name: Nikolov, Nikolay K.
name: Palle, Enric
name: Petit Dit De La Roche, Dominique J. M.
name: Piaulet, Caroline
name: Powell, Diana
name: Redfield, Seth
name: Rogers, Laura K.
name: Roman, Michael T.
name: Roy, Pierre-Alexis
name: Nixon, Matthew C.
name: Schlawin, Everett
name: Tan, Xianyu
name: Tremblin, P.
name: Turner, Jake D.
name: Venot, Olivia
name: Waalkes, William C.
name: Wheatley, Peter J.
name: Zhang, Xi
Publisher: name: Apollo - University of Cambridge Repository
Year: 2023
Subjects: Article
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/639/33/445/862
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article

description: The Saturn-mass exoplanet WASP-39b has been the subject of extensive efforts to determine its atmospheric properties using transmission spectroscopy1–4. However, these efforts have been hampered by modelling degeneracies between composition and cloud properties that are caused by limited data quality5–9. Here we present the transmission spectrum of WASP-39b obtained using the Single-Object Slitless Spectroscopy (SOSS) mode of the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument on the JWST. This spectrum spans 0.6–2.8 μm in wavelength and shows several water-absorption bands, the potassium resonance doublet and signatures of clouds. The precision and broad wavelength coverage of NIRISS/SOSS allows us to break model degeneracies between cloud properties and the atmospheric composition of WASP-39b, favouring a heavy-element enhancement (‘metallicity’) of about 10–30 times the solar value, a sub-solar carbon-to-oxygen (C/O) ratio and a solar-to-super-solar potassium-to-oxygen (K/O) ratio. The observations are also best explained by wavelength-dependent, non-grey clouds with inhomogeneous coverageof the planet’s terminator.