Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM

Abstract Transmission spectroscopy 1–3 of exoplanets has revealed signatures of water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres 4,5 . However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations’ relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species—in particular the primary carbon-bearing molecules 6,7 . Here we report a broad-wavelength 0.5–5.5 µm atmospheric transmission spectrum of WASP-39b 8 , a 1,200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with the JWST NIRSpec’s PRISM mode 9 as part of the JWST Transiting Exoplanet…

• NA
  National Aeronautics and Space Administration

  Awards: 5-03127, NAS 5-03127, JWST-ERS-01366
• UO
  University of California, Santa Cruz
• ST
  Space Telescope Science Institute

  Awards: 5-03127, NAS 5-03127
• HF
  Heising-Simons Foundation
• SA
  Science and Technology Facilities Council

  Awards: ST/T004479/1, ST/P000495/1, ST/X001121/1, ST/R003726/1, ST/R000395/1, ST/V000861/1, ST/T000406/1