skip to main content

Title: Warm Spitzer and Palomar near-IR secondary eclipse photometry of two hot Jupiters: WASP-48b and HAT-P-23b

We report secondary eclipse photometry of two hot Jupiters, WASP-48b and HAT-P-23b, at 3.6 and 4.5 μm taken with the InfraRed Array Camera aboard the Spitzer Space Telescope during the warm Spitzer mission and in the H and K{sub S} bands with the Wide Field IR Camera at the Palomar 200 inch Hale Telescope. WASP-48b and HAT-P-23b are Jupiter-mass and twice Jupiter-mass objects orbiting an old, slightly evolved F star and an early G dwarf star, respectively. In the H, K{sub S} , 3.6 μm, and 4.5 μm bands, respectively, we measure secondary eclipse depths of 0.047% ± 0.016%, 0.109% ± 0.027%, 0.176% ± 0.013%, and 0.214% ± 0.020% for WASP-48b. In the K{sub S} , 3.6 μm, and 4.5 μm bands, respectively, we measure secondary eclipse depths of 0.234% ± 0.046%, 0.248% ± 0.019%, and 0.309% ± 0.026% for HAT-P-23b. For WASP-48b and HAT-P-23b, respectively, we measure delays of 2.6 ± 3.9 minutes and 4.0 ± 2.4 minutes relative to the predicted times of secondary eclipse for circular orbits, placing 2σ upper limits on |ecos ω| of 0.0053 and 0.0080, both of which are consistent with circular orbits. The dayside emission spectra of these planets are well-described by blackbodiesmore » with effective temperatures of 2158 ± 100 K (WASP-48b) and 2154 ± 90 K (HAT-P-23b), corresponding to moderate recirculation in the zero albedo case. Our measured eclipse depths are also consistent with one-dimensional radiative transfer models featuring varying degrees of recirculation and weak thermal inversions or no inversions at all. We discuss how the absence of strong temperature inversions on these planets may be related to the activity levels and metallicities of their host stars.« less
Authors:
; ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [10]
  1. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)
  2. Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States)
  3. Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)
  4. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 05844 (United States)
  5. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States)
  6. Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)
  7. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
  8. Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)
  9. Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)
  10. Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland)
Publication Date:
OSTI Identifier:
22348093
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; DWARF STARS; ECLIPSE; EMISSION SPECTRA; JUPITER PLANET; MASS; METALLICITY; NEAR INFRARED RADIATION; ONE-DIMENSIONAL CALCULATIONS; ORBITS; PHOTOMETRY; RADIANT HEAT TRANSFER; SPACE; TELESCOPES; TEMPERATURE INVERSIONS; WASPS