Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM
Zafar Rustamkulov, David K. Sing, S. Mukherjee, Erin May, James Kirk, Everett Schlawin, Michael Line, Caroline Piaulet, Aarynn L. Carter, N. E. Batalha, Jayesh Goyal, Mercedes López‐Morales, Joshua D. Lothringer, Ron MacDonald, Sarah E. Moran, Kevin B. Stevenson, Hannah R. Wakeford, N. Espinoza, J. L. Bean, N. M. Batalha, Björn Benneke, Zachory K. Berta-Thompson, Ian J. M. Crossfield, Peter Gao, Laura Kreidberg, Diana Powell, P. E. Cubillos, Neale P. Gibson, J. Leconte, Karan Molaverdikhani, Nikolay Nikolov, Vivien Parmentier, P. Roy, Jake Taylor, J. D. Turner, P. J. Wheatley, Keshav Aggarwal, Eva-Maria Ahrer, Munazza K. Alam, Lili Alderson, Natalie H. Allen, Agnibha Banerjee, Saugata Barat, D. Barrado, J. K. Barstow, Taylor J. Bell, J. Blecic, J. Brande, S. L. Casewell, Q. Changeat, K. L. Chubb, Nicolas Crouzet, Tansu Daylan, L. Decin, Jean-Michel Désert, T. M. Evans, Adina D. Feinstein, Laura Flagg, J. J. Fortney, Joseph Harrington, Kevin Heng, Y. Hong, Renyu Hu, Nicolas Iro, Tiffany Kataria, Eliza M.-R. Kempton, Jessica Krick, M. Lendl, J. Lillo-Box, A. Louca, Jacob Lustig‐Yaeger, L. Mancini, Megan Mansfield, Nathan J. Mayne, Yamila Miguel, Giuseppe Morello, Kazumasa Ohno, Ε. Πάλλη, D. J. M. Petit dit de la Roche, Benjamin V. Rackham, Michael Radica, L. Ramos-Rosado, Seth Redfield, Laura K. Rogers, Evgenya L. Shkolnik, J. Southworth, Johanna Teske, Pascal Tremblin, G. S. Tucker, Olivia Vénot, William C. Waalkes, Luis Welbanks, Xi Zhang, Sebastian Zieba
Abstract
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 Community Early Release Science Team Program 10–12 . We robustly detect several chemical species at high significance, including Na (19 σ ), H 2 O (33 σ ), CO 2 (28 σ ) and CO (7 σ ). The non-detection of CH 4 , combined with a strong CO 2 feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4 µm is best explained by SO 2 (2.7 σ ), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST’s sensitivity to a rich diversity of exoplanet compositions and chemical processes.