Early Release Science of the exoplanet WASP-39b with JWST NIRSpec G395H
Abstract
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 an exoplanet’s chemical inventory 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 3–5 μm covering multiple absorption features for the Saturn-mass exoplanet WASP-39b9, obtained with JWST NIRSpec G395H. Our observations achieve 1.46× 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 μ m (4.8σ ). Best-fit atmospheric models range between 3× and 10× solar metallicity, with sub-solar to solar C/O ratios. These results, including the detection of SO2, underscore the importance of characterising the chemistry in exoplanet atmospheres, and showcase NIRSpec G395H as an excellent mode for time series observations over this critical wavelength range10.
Citation
Alderson , L , Wakeford , H R , Alam , M K , Batalha , N E , Lothringer , J D , Redai , J A , Barat , S , Brande , J , Damiano , M , Daylan , T , Espinoza , N , Flagg , L , Goyal , J M , Grant , D , Hu , R , Inglis , J , Lee , E K H , Mikal-Evans , T , Ramos-Rosado , L , Roy , P-A , Wallack , N L , Batalha , N M , Bean , J L , Benneke , B , Berta-Thompson , Z K , Carter , A L , Changeat , Q , Colón , K D , Crossfield , I J M , Désert , J-M , Foreman-Mackey , D , Gibson , N P , Kreidberg , L , Line , M R , López-Morales , M , Molaverdikhani , K , Moran , S E , Morello , G , Moses , J I , Mukherjee , S , Schlawin , E , Sing , D K , Stevenson , K B , Taylor , J , Aggarwal , K , Ahrer , E-M , Allen , N H , Barstow , J K , Bell , T J , Blecic , J , Casewell , S L , Chubb , K L , Crouzet , N , Cubillos , P E , Decin , L , Feinstein , A D , Fortney , J J , Harrington , J , Heng , K , Iro , N , Kempton , E M -R , Kirk , J , Knutson , H A , Krick , J , Leconte , J , Lendl , M , MacDonald , R J , Mancini , L , Mansfield , M , May , E M , Mayne , N J , Miguel , Y , Nikolov , N K , Ohno , K , Palle , E , Parmentier , V , Petit dit de la Roche , D J M , Piaulet , C , Powell , D , Rackham , B V , Redfield , S , Rogers , L K , Rustamkulov , Z , Tan , X , Tremblin , P , Tsai , S-M , Turner , J D , de Val-Borro , M , Venot , O , Welbanks , L , Wheatley , P J & Zhang , X 2023 , ' Early Release Science of the exoplanet WASP-39b with JWST NIRSpec G395H ' , Nature , vol. 614 , no. 7949 , pp. 664-669 . https://doi.org/10.1038/s41586-022-05591-3
Publication
Nature
Status
Peer reviewed
ISSN
0028-0836Type
Journal article
Description
Funding: Support for program JWSTERS-01366 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127. LA acknowledges funding from STFC grant ST/W507337/1 and from the University of Bristol School of Physics PhD Scholarship Fund.Collections
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