skip to main content

Title: Spitzer observations of the thermal emission from WASP-43b

WASP-43b is one of the closest-orbiting hot Jupiters, with a semimajor axis of a = 0.01526 ± 0.00018 AU and a period of only 0.81 days. However, it orbits one of the coolest stars with a hot Jupiter (T {sub *} = 4520 ± 120 K), giving the planet a modest equilibrium temperature of T {sub eq} = 1440 ± 40 K, assuming zero Bond albedo and uniform planetary energy redistribution. The eclipse depths and brightness temperatures from our jointly fit model are 0.347% ± 0.013% and 1670 ± 23 K at 3.6 μm and 0.382% ± 0.015% and 1514 ± 25 K at 4.5 μm. The eclipse timings improved the estimate of the orbital period, P, by a factor of three (P = 0.81347436 ± 1.4 × 10{sup –7} days) and put an upper limit on the eccentricity (e=0.010{sub −0.007}{sup +0.010}). We use our Spitzer eclipse depths along with four previously reported ground-based photometric observations in the near-infrared to constrain the atmospheric properties of WASP-43b. The data rule out a strong thermal inversion in the dayside atmosphere of WASP-43b. Model atmospheres with no thermal inversions and fiducial oxygen-rich compositions are able to explain all the available data. However, amore » wide range of metallicities and C/O ratios can explain the data. The data suggest low day-night energy redistribution in the planet, consistent with previous studies, with a nominal upper limit of about 35% for the fraction of energy incident on the dayside that is redistributed to the nightside.« less
Authors:
; ; ; ; ; ; ;  [1] ;  [2] ; ; ;  [3] ;  [4]
  1. Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States)
  2. Department of Physics and Department of Astronomy, Yale University, New Haven, CT 06511 (United States)
  3. Astrophysics Group, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom)
  4. SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom)
Publication Date:
OSTI Identifier:
22348077
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 781; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BRIGHTNESS; ECLIPSE; EMISSION; EQUILIBRIUM; JUPITER PLANET; METALLICITY; ORBITS; OXYGEN; SATELLITE ATMOSPHERES; SATELLITES; STARS; TEMPERATURE INVERSIONS; WASPS