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 4

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.3847/1538-3881/ad434d

More information

Latest update

8/7/2024 1