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, SL
name: Chubb, Katy L
name: Crossfield, Ian JM
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, EM
name: Mayne, NJ
name: Nikolov, Nikolay K
name: Palle, Enric
name: Petit Dit De La Roche, Dominique JM
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.