Two-dimensional Eclipse Mapping of the Hot-Jupiter WASP-43b with JWST MIRI/LRS
Journal article, 2024
We present eclipse maps of the two-dimensional thermal emission from the dayside of the hot-Jupiter WASP-43b, derived from an observation of a phase curve with the JWST MIRI/LRS instrument. The observed eclipse shapes deviate significantly from those expected for a planet emitting uniformly over its surface. We fit a map to this deviation, constructed from spherical harmonics up to order ℓ max = 2 , alongside the planetary, orbital, stellar, and systematic parameters. This yields a map with a meridionally averaged eastward hot-spot shift of (7.75 ± 0.36)°, with no significant degeneracy between the map and the additional parameters. We show the latitudinal and longitudinal contributions of the dayside emission structure to the eclipse shape, finding a latitudinal signal of ∼200 ppm and a longitudinal signal of ∼250 ppm. To investigate the sensitivity of the map to the method, we fix the parameters not used for mapping and derive an “eigenmap” fitted with an optimized number of orthogonal phase curves, which yields a similar map to the ℓ max = 2 map. We also fit a map up to ℓ max = 3 , which shows a smaller hot-spot shift, with a larger uncertainty. These maps are similar to those produced by atmospheric simulations. We conclude that there is a significant mapping signal which constrains the spherical harmonic components of our model up to ℓ max = 2 . Alternative mapping models may derive different structures with smaller-scale features; we suggest that further observations of WASP-43b and other planets will drive the development of more robust methods and more accurate maps.
Author
Mark Hammond
University of Oxford
Taylor Bell
NASA Ames Research Center
Ryan C. Challener
University of Michigan
Cornell University
Neil T. Lewis
University of Exeter
Megan Weiner Mansfield
University of Arizona
Isaac Malsky
University of Michigan
Emily Rauscher
University of Michigan
Jacob L. Bean
University of Chicago
L. Carone
Institut fur Weltraumforschung
João M. Mendonça
Technical University of Denmark (DTU)
Lucas Teinturier
Pierre and Marie Curie University (UPMC)
Paris Observatory
Xianyu Tan
Shanghai Jiao Tong University
N. Crouzet
Leiden University
L. Kreidberg
Max Planck Society
Giuseppe Morello
Instituto de Astrofísica de Canarias
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Institute of Astrophysics of Andalusia (IAA)
Vivien Parmentier
Observatoire de la Cote d'Azur
Jasmina Blecic
New York University Abu Dhabi
J. M. Desert
Anton Pannekoek Institute for Astronomy
Ch. Helling
Institut fur Weltraumforschung
Technische Universität Graz
P. O. Lagage
University Paris-Saclay
K. Molaverdikhani
Ludwig Maximilian University of Munich (LMU)
M. C. Nixon
University of Maryland
Benjamin V. Rackham
Massachusetts Institute of Technology (MIT)
Jingxuan Yang
University of Oxford
Astronomical Journal
0004-6256 (ISSN) 1538-3881 (eISSN)
Vol. 168 1 4Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.3847/1538-3881/ad434d