Nightside clouds and disequilibrium chemistry on the hot Jupiter WASP-43b
Journal article, 2024
Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models predict that clouds may condense on the nightside and that molecular abundances can be driven out of equilibrium by zonal winds. Here we report a phase-resolved emission spectrum of the hot Jupiter WASP-43b measured from 5 μm to 12 μm with the JWST’s Mid-Infrared Instrument. The spectra reveal a large day–night temperature contrast (with average brightness temperatures of 1,524 ± 35 K and 863 ± 23 K, respectively) and evidence for water absorption at all orbital phases. Comparisons with three-dimensional atmospheric models show that both the phase-curve shape and emission spectra strongly suggest the presence of nightside clouds that become optically thick to thermal emission at pressures greater than ~100 mbar. The dayside is consistent with a cloudless atmosphere above the mid-infrared photosphere. Contrary to expectations from equilibrium chemistry but consistent with disequilibrium kinetics models, methane is not detected on the nightside (2σ upper limit of 1–6 ppm, depending on model assumptions). Our results provide strong evidence that the atmosphere of WASP-43b is shaped by disequilibrium processes and provide new insights into the properties of the planet’s nightside clouds. However, the remaining discrepancies between our observations and our predictive atmospheric models emphasize the importance of further exploring the effects of clouds and disequilibrium chemistry in numerical models.
Author
Taylor Bell
NASA Ames Research Center
N. Crouzet
Leiden University
P. E. Cubillos
Institut fur Weltraumforschung
Istituto nazionale di astrofisica (INAF)
L. Kreidberg
Max Planck Society
Anjali A.A. Piette
Carnegie Institution of Washington
Michael T. Roman
Adolfo Ibáñez University
University Of Leicester
J. Barstow
Open University
Jasmina Blecic
New York University Abu Dhabi
L. Carone
Institut fur Weltraumforschung
Louis Philippe Coulombe
Université de Montréal
E. Ducrot
University Paris-Saclay
Mark Hammond
University of Oxford
João M. Mendonça
Technical University of Denmark (DTU)
Julianne I. Moses
Space Science Institute
Vivien Parmentier
Observatoire de la Cote d'Azur
Kevin B. Stevenson
The Johns Hopkins University Applied Physics Laboratory
Lucas Teinturier
Paris Observatory
Pierre and Marie Curie University (UPMC)
Michael Zhang
University of Chicago
Natalie Batalha
University of California
Jacob L. Bean
University of Chicago
B. Benneke
Université de Montréal
Bejamin Charnay
Paris Observatory
Katy L. Chubb
University of St Andrews
B.O. Demory
Physics Institute
University of Bern
Peter Gao
Carnegie Institution of Washington
Elspeth K.H. Lee
University of Bern
Mercedes López-Morales
Harvard-Smithsonian Center for Astrophysics
Giuseppe Morello
Istituto nazionale di astrofisica (INAF)
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Instituto de Astrofísica de Canarias
Emily Rauscher
University of Michigan
David K. Sing
Johns Hopkins University
Xianyu Tan
Shanghai Jiao Tong University
University of Oxford
Olivia Venot
Université Paris-Est Créteil Val de Marne
Hannah R. Wakeford
University of Bristol
Keshav Aggarwal
Indian Institute of Technology
Eva Maria Ahrer
The University of Warwick
Munazza K. Alam
Carnegie Institution of Washington
Robin Baeyens
Anton Pannekoek Institute for Astronomy
D. Barrado
European Space Astronomy Centre (ESAC)
Claudio Caceres
Universidad Andrés Bello
Núcleo Milenio de Formación Planetaria (NPF)
Centro de Astrofísica y Tecnologías Afines (CATA),
Aarynn L. Carter
University of California
Sarah Casewell
University Of Leicester
Ryan C. Challener
University of Michigan
I. J.M. Crossfield
University of Kansas
L. Decin
KU Leuven
J. M. Desert
Anton Pannekoek Institute for Astronomy
Ian Dobbs-Dixon
New York University Abu Dhabi
A. Dyrek
University Paris-Saclay
Néstor Espinoza
Space Telescope Science Institute (STScI)
Johns Hopkins University
A. D. Feinstein
University of Colorado at Boulder
University of Chicago
Neale P. Gibson
Trinity College Dublin
Joseph Harrington
University of Central Florida
Ch. Helling
Institut fur Weltraumforschung
Renyu Hu
California Institute of Technology (Caltech)
Nicolas Iro
German Aerospace Center (DLR)
Eliza M.R. Kempton
University of Maryland
S. Kendrew
European Space Agency (ESA)
Thaddeus D. Komacek
University of Maryland
Jessica Krick
California Institute of Technology (Caltech)
P. O. Lagage
University Paris-Saclay
J. Leconte
Laboratoire d'Astrophysique de Bordeaux
M. Lendl
University of Geneva
Neil T. Lewis
University of Exeter
Joshua D. Lothringer
Utah Valley University
Isaac Malsky
University of Michigan
Luigi Mancini
University of Rome Tor Vergata
Max Planck Society
Istituto nazionale di astrofisica (INAF)
Megan Mansfield
University of Arizona
Nathan J. Mayne
University of Exeter
Thomas M. Evans-Soma
Max Planck Society
University of Newcastle
K. Molaverdikhani
Ludwig Maximilian University of Munich (LMU)
Nikolay K. Nikolov
Space Telescope Science Institute (STScI)
M. C. Nixon
University of Maryland
Enric Palle
Instituto de Astrofísica de Canarias
Dominique J.M. Petit dit de la Roche
University of Geneva
Caroline Piaulet
Université de Montréal
Diana Powell
Harvard-Smithsonian Center for Astrophysics
Benjamin V. Rackham
Massachusetts Institute of Technology (MIT)
Aaron D. Schneider
KU Leuven
Niels Bohr Institute
Maria E. Steinrueck
Max Planck Society
Jake Taylor
University of Oxford
Université de Montréal
Luis Welbanks
Arizona State University
Sergey N. Yurchenko
University College London (UCL)
Xi Zhang
University of California
Sebastian Zieba
Max Planck Society
Leiden University
Nature Astronomy
23973366 (eISSN)
Vol. In PressSubject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1038/s41550-024-02230-x