title: Exoplanet atmosphere. Thermal structure of an exoplanet atmosphere from phase-resolved emission spectroscopy.
abstract: Exoplanets that orbit close to their host stars are much more highly irradiated than their solar system counterparts. Understanding the thermal structures and appearances of these planets requires investigating how their atmospheres respond to such extreme stellar forcing. We present spectroscopic thermal emission measurements as a function of orbital phase ("phase-curve observations") for the highly irradiated exoplanet WASP-43b spanning three full planet rotations using the Hubble Space Telescope. With these data, we construct a map of the planet's atmospheric thermal structure, from which we find large day-night temperature variations at all measured altitudes and a monotonically decreasing temperature with pressure at all longitudes. We also derive a Bond albedo of 0.18(-0.12)(+0.07) and an altitude dependence in the hot-spot offset relative to the substellar point.
authors.affiliation: Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA. NASA Sagan Fellow. kbs@uchicago.edu.
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Stevenson
authors.affiliation: CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309, USA.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Désert
authors.affiliation: Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Line
authors.affiliation: Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA.
authors.forename: Jacob L
authors.initials: JL
authors.lastname: Bean
authors.affiliation: Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Fortney
authors.affiliation: Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Adam P
authors.initials: AP
authors.lastname: Showman
authors.affiliation: Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Kataria
authors.affiliation: Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Kreidberg
authors.affiliation: Space Telescope Science Institute, Baltimore, MD 21218, USA. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA.
authors.forename: Peter R
authors.initials: PR
authors.lastname: McCullough
authors.affiliation: Center for Excellence in Information Systems, Tennessee State University, Nashville, TN 37209, USA.
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Henry
authors.affiliation: Department of Astronomy, Harvard University, Cambridge, MA 02138, USA.
authors.forename: David
authors.initials: D
authors.lastname: Charbonneau
authors.affiliation: Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Burrows
authors.affiliation: Department of Earth, Atmospheric, and Planetary Sciences, Department of Physics, Massachusetts Institute of Technology, 54-1718, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Seager
authors.affiliation: Institute of Astronomy, University of Cambridge, Cambridge CB3 OHA, UK.
authors.forename: Nikku
authors.initials: N
authors.lastname: Madhusudhan
authors.affiliation: Center for Excellence in Information Systems, Tennessee State University, Nashville, TN 37209, USA.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Williamson
authors.affiliation: Centre de Recherche Astrophysique de Lyon, UMR 5574, CNRS, Université de Lyon, École Normale Supérieure de Lyon, 46 Allée d'Italie, F-69364 Lyon Cedex 07, France.
authors.forename: Derek
authors.initials: D
authors.lastname: Homeier