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Trends in Spitzer Secondary Eclipses

Wallack, Nicole L. and Knutson, Heather A. and Deming, Drake (2021) Trends in Spitzer Secondary Eclipses. Astronomical Journal, 162 (1). Art. No. 36. ISSN 0004-6256. doi:10.3847/1538-3881/abdbb2.

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It is well established that the magnitude of the incident stellar flux is the single most important factor in determining the day–night temperature gradients and atmospheric chemistries of short-period gas giant planets. However, it is likely that other factors, such as planet-to-planet variations in atmospheric metallicity, C/O ratio, and cloud properties, also contribute to the observed diversity of infrared spectra for this population of planets. In this study, we present new 3.6 and 4.5 μm secondary eclipse measurements for five transiting gas giant planets: HAT-P-5b, HAT-P-38b, WASP-7b, WASP-72b, and WASP-127b. We detect eclipses in at least one bandpass for all five planets and confirm circular orbits for all planets except WASP-7b, which shows evidence for a nonzero eccentricity. Building on the work of Garhart et al., we place these new planets into a broader context by comparing them with the sample of all planets with measured Spitzer secondary eclipses. We find that incident flux is the single most important factor for determining the atmospheric chemistry and circulation patterns of short-period gas giant planets. Although we might also expect surface gravity and host star metallicity to play a secondary role, we find no evidence for correlations with either of these two variables.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Wallack, Nicole L.0000-0003-0354-0187
Knutson, Heather A.0000-0002-0822-3095
Deming, Drake0000-0001-5727-4094
Additional Information:© 2021. The American Astronomical Society. Received 2020 February 27; revised 2021 January 1; accepted 2021 January 12; published 2021 June 29. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.
Funding AgencyGrant Number
Subject Keywords:Exoplanet atmospheres; Exoplanet atmospheric composition; Exoplanets; Broad band photometry; Infrared photometry
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Exoplanet atmospheres (487); Exoplanet atmospheric composition (2021); Exoplanets (498); Broad band photometry (184); Infrared photometry (792)
Record Number:CaltechAUTHORS:20210416-095221107
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108755
Deposited By: Tony Diaz
Deposited On:16 Apr 2021 18:42
Last Modified:08 Jul 2021 21:13

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