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 +0.07,-0.12 and an altitude dependence in the hot-spot offset relative to the substellar point.

28 pages, 12 figures, 1 movie, includes supplementary materials, accepted for publication in Science. Also see two companion papers titled "A Precise Water Abundance Measurement for the Hot Jupiter WASP-43b" by Kreidberg et al. (2014b) and "The atmospheric circulation of the hot Jupiter WASP-43b: Comparing three-dimensional models to spectrophotometric data" by Kataria et al. (2014)

References in corpus (5)

• A Precise Water Abundance Measurement for the Hot Jupiter WASP-43b
• Inverting Phase Functions to Map Exoplanets
• Vertical Atmospheric Structure in a Variable Brown Dwarf: Pressure-dependent Phase Shifts in Simultaneous Hubble Space Telescope-Spitzer Light Curves
• A New 24 micron Phase Curve for upsilon Andromedae b
• Optical Albedo Theory of Strongly-Irradiated Giant Planets: The Case of HD 209458b

Cited by in corpus (9)

• Changing Phases of Alien Worlds: Probing Atmospheres of Kepler Planets with High-Precision Photometry
• The Atmospheric Circulation of the Hot Jupiter WASP-43b: Comparing Three-Dimensional Models to Spectrophotometric Data
• Balancing the Energy Budget of Short-Period Giant Planets: Evidence for Reflective Clouds and Optical Absorbers
• Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
• Evidence for a spectroscopic direct detection of reflected light from 51 Peg b
• HST PanCET program: A Cloudy Atmosphere for the promising JWST target WASP-101b
• A Hubble Space Telescope Search for a Sub-Earth-Sized Exoplanet in the GJ 436 System
• Challenges to Constraining Exoplanet Masses via Transmission Spectroscopy
• Illusion and Reality in the Atmospheres of Exoplanets