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

Author(s): Eva Maria Ahrer, Kevin B. Stevenson, Megan Mansfield, Sarah E. Moran, Jonathan Brande, Giuseppe Morello, Catriona A. Murray, Nikolay K. Nikolov, Dominique J.M. Petit dit de la Roche, Everett Schlawin, Peter J. Wheatley, Sebastian Zieba, Natasha E. Batalha, Mario Damiano, Jayesh M. Goyal, Monika Lendl, Joshua D. Lothringer, Sagnick Mukherjee, Kazumasa Ohno, Natalie M. Batalha, Matthew P. Battley, Jacob L. Bean, Thomas G. Beatty, Björn Benneke, Zachory K. Berta-Thompson, Aarynn L. Carter, Patricio E. Cubillos, Tansu Daylan, Néstor Espinoza, Peter Gao, Neale P. Gibson, Samuel Gill, Joseph Harrington, Renyu Hu, Laura Kreidberg, Nikole K. Lewis, Michael R. Line, Mercedes López-Morales, Vivien Parmentier, Diana K. Powell, David K. Sing, Shang Min Tsai, Hannah R. Wakeford, Luis Welbanks, Munazza K. Alam, Lili Alderson, Natalie H. Allen, David R. Anderson, Joanna K. Barstow, Daniel Bayliss, Taylor J. Bell, Jasmina Blecic, Edward M. Bryant, Matthew R. Burleigh, Ludmila Carone, S. L. Casewell, Quentin Changeat, Katy L. Chubb, Ian J.M. Crossfield, Nicolas Crouzet, Leen Decin, Jean Michel Désert, Adina D. Feinstein, Laura Flagg, Jonathan J. Fortney, John E. Gizis, Kevin Heng, Nicolas Iro, Eliza M.R. Kempton, Sarah Kendrew, James Kirk, Heather A. Knutson, Thaddeus D. Komacek, Pierre Olivier Lagage, Jérémy Leconte, Jacob Lustig-Yaeger, Ryan J. MacDonald, Luigi Mancini, E. M. May, N. J. Mayne, Yamila Miguel, Thomas Mikal-Evans, Karan Molaverdikhani, Enric Palle, Caroline Piaulet, Benjamin V. Rackham, Seth Redfield, Laura K. Rogers, Pierre Alexis Roy, Zafar Rustamkulov, Evgenya L. Shkolnik, Kristin S. Sotzen, Jake Taylor, P. Tremblin, Gregory S. Tucker, Jake D. Turner, Miguel de Val-Borro, Olivia Venot, Xi Zhang
Abstract: Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories. Transmission spectroscopy (for example, refs. ^1,2) provides the necessary means by constraining the abundances of oxygen- and carbon-bearing species; however, this requires broad wavelength coverage, moderate spectral resolution and high precision, which, together, are not achievable with previous observatories. Now that JWST has commenced science operations, we are able to observe exoplanets at previously uncharted wavelengths and spectral resolutions. Here we report time-series observations of the transiting exoplanet WASP-39b using JWST’s Near InfraRed Camera (NIRCam). The long-wavelength spectroscopic and short-wavelength photometric light curves span 2.0–4.0 micrometres, exhibit minimal systematics and reveal well defined molecular absorption features in the planet’s spectrum. Specifically, we detect gaseous water in the atmosphere and place an upper limit on the abundance of methane. The otherwise prominent carbon dioxide feature at 2.8 micrometres is largely masked by water. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1–100-times solar (that is, an enrichment of elements heavier than helium relative to the Sun) and a substellar C/O ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formation (for example, refs. ^3,4^,) or disequilibrium processes in the upper atmosphere (for example, refs. ^5,6).
Organisation(s): Department of Astrophysics
External organisation(s): University of Warwick, Johns Hopkins University, University of Arizona, University of Kansas, Institute of Astrophysics of the Canary Islands, University of La Laguna, INAF-Osservatorio Astrofisico di Torino, University of Colorado, Boulder, Space Telescope Science Institute, Université de Genève, Max-Planck-Institut für Astronomie, Leiden University, National Aeronautics & Space Administration (NASA), California Institute of Technology (Caltech), Utah Valley University, University of California, Santa Cruz, University of Chicago, University of Wisconsin, Madison, Österreichische Akademie der Wissenschaften (ÖAW), Princeton University, Carnegie Institution for Science, University of Dublin, University of Central Florida, Cornell University, Arizona State University, Harvard-Smithsonian Center for Astrophysics, University of Oxford, Université Côte d'Azur, Johns Hopkins University Krieger School of Arts and Sciences, University of Bristol, Open University, New York University Abu Dhabi, University College London, University of Leicester, European Space Astronomy Centre (ESA), University of St. Andrews, Katholieke Universiteit Leuven, University of Amsterdam (UvA), University of Delaware, Ludwig-Maximilians-Universität München, Universität Bern, University of Maryland, College Park, Imperial College London, Université Paris Saclay, Laboratoire d'Astrophysique de Bordeaux, University of Michigan, Università degli Studi di Roma "Tor Vergata", University of Exeter, SRON Netherlands Institute for Space Research , Massachusetts Institute of Technology, Wesleyan University, University of Cambridge, IRFU CEA-Saclay laboratory , Brown University, Université Paris VII - Paris-Diderot, National Institute of Science Education and Research, University of Montreal, Planetary Science Institute
Journal: Nature
Volume: 614
Pages: 653-658
No. of pages: 6
ISSN: 0028-0836
DOI: https://doi.org/10.1038/s41586-022-05590-4
Publication date: 02-2023
Peer reviewed: Yes
Austrian Fields of Science 2012: 103004 Astrophysics
ASJC Scopus subject areas: General
Portal url: https://ucrisportal.univie.ac.at/en/publications/f77eb06a-371a-41f8-ae1c-1181036b3dce

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