Early Release Science of the exoplanet WASP-39b with JWST NIRSpec G395H
Creators: name: Alderson, Lili
name: Wakeford, Hannah R.
name: Alam, Munazza K.
name: Batalha, Natasha E.
name: Lothringer, Joshua D.
name: Adams Redai, Jea
name: Barat, Saugata
name: Brande, Jonathan
name: Damiano, Mario
name: Daylan, Tansu
name: Espinoza, Néstor
name: Flagg, Laura
name: Goyal, Jayesh M.
name: Grant, David
name: Hu, Renyu
name: Inglis, Julie
name: Lee, Elspeth K. H.
name: Mikal-Evans, Thomas
name: Ramos-Rosado, Lakeisha
name: Roy, Pierre-Alexis
name: Wallack, Nicole L.
name: Batalha, Natalie M.
name: Bean, Jacob L.
name: Benneke, Björn
name: Berta-Thompson, Zachory K.
name: Carter, Aarynn L.
name: Changeat, Quentin
name: Colón, Knicole D.
name: Crossfield, Ian J. M.
name: Désert, Jean-Michel
name: Foreman-Mackey, Daniel
name: Gibson, Neale P.
name: Kreidberg, Laura
name: Line, Michael R.
name: López-Morales, Mercedes
name: Molaverdikhani, Karan
name: Moran, Sarah E.
name: Morello, Giuseppe
name: Moses, Julianne I.
name: Mukherjee, Sagnick
name: Schlawin, Everett
name: Sing, David K.
name: Stevenson, Kevin B.
name: Taylor, Jake
name: Aggarwal, Keshav
name: Ahrer, Eva-Maria
name: Allen, Natalie H.
name: Barstow, Joanna K.
name: Bell, Taylor J.
name: Blecic, Jasmina
name: Casewell, Sarah L.
name: Chubb, Katy L.
name: Crouzet, Nicolas
name: Cubillos, Patricio E.
name: Decin, Leen
name: Feinstein, Adina D.
name: Fortney, Joanthan J.
name: Harrington, Joseph
name: Heng, Kevin
name: Iro, Nicolas
name: Kempton, Eliza M.-R.
name: Kirk, James
name: Knutson, Heather A.
name: Krick, Jessica
name: Leconte, Jérémy
name: Lendl, Monika
name: MacDonald, Ryan J.
name: Mancini, Luigi
name: Mansfield, Megan
name: May, Erin M.
name: Mayne, Nathan J.
name: Miguel, Yamila
name: Nikolov, Nikolay K.
name: Ohno, Kazumasa
name: Palle, Enric
name: Parmentier, Vivien
name: Petit Dit De La Roche, Dominique J. M.
name: Piaulet, Caroline
name: Powell, Diana
name: Rackham, Benjamin V.
name: Redfield, Seth
name: Rogers, Laura K.
name: Rustamkulov, Zafar
name: Tan, Xianyu
name: Tremblin, P.
name: Tsai, Shang-Min
name: Turner, Jake D.
name: De Val-Borro, Miguel
name: Venot, Olivia
name: Welbanks, Luis
name: Wheatley, Peter J.
name: Zhang, Xi
Publisher: name: Apollo - University of Cambridge Repository
Year: 2023
Subjects: Article
/639/33/34/862
/639/33/34/2810
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article

description: Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking the formation and evolution of exoplanetary systems1, 2. Access to the chemical inventory of an exoplanet requires high-precision observations, often inferred from individual molecular detections with low-resolution space-based3–5 and high-resolution ground-based6–8 facilities. Here we report the medium-resolution (R ≈ 600) transmission spectrum of an exoplanet atmosphere between 3 and 5 μm covering several absorption features for the Saturn-mass exoplanet WASP-39b (ref. 9), obtained with the Near Infrared Spectrograph (NIRSpec) G395H grating of JWST. Our observations achieve 1.46 times photon precision, providing an average transit depth uncertainty of 221 ppm per spectroscopic bin, and present minimal impacts from systematic effects. We detect significant absorption from CO2 (28.5σ) and H2O (21.5σ), and identify SO2 as the source of absorption at 4.1 μm (4.8σ). Best-fit atmospheric models range between 3 and 10 times solar metallicity, with sub-solar to solar C/O ratios. These results, including the detection of SO2, underscore the importance of characterizing the chemistry in exoplanet atmospheres and showcase NIRSpec G395H as an excellent mode for time-series observations over this critical wavelength range10.