A Spitzer five-band analysis of the Jupiter-sized planet TrES-1

Journal Article · Wed Dec 10 00:00:00 EST 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/797/1/42· OSTI ID:22370046

Cubillos, Patricio; Harrington, Joseph; Foster, Andrew S. D.; Lust, Nate B.; Hardy, Ryan A.; Bowman, M. Oliver ^[1]; Madhusudhan, Nikku ^[2]

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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)

With an equilibrium temperature of 1200 K, TrES-1 is one of the coolest hot Jupiters observed by Spitzer. It was also the first planet discovered by any transit survey and one of the first exoplanets from which thermal emission was directly observed. We analyzed all Spitzer eclipse and transit data for TrES-1 and obtained its eclipse depths and brightness temperatures in the 3.6 μm (0.083% ± 0.024%, 1270 ± 110 K), 4.5 μm (0.094% ± 0.024%, 1126 ± 90 K), 5.8 μm (0.162% ± 0.042%, 1205 ± 130 K), 8.0 μm (0.213% ± 0.042%, 1190 ± 130 K), and 16 μm (0.33% ± 0.12%, 1270 ± 310 K) bands. The eclipse depths can be explained, within 1σ errors, by a standard atmospheric model with solar abundance composition in chemical equilibrium, with or without a thermal inversion. The combined analysis of the transit, eclipse, and radial-velocity ephemerides gives an eccentricity of e=0.033{sub −0.031}{sup +0.015}, consistent with a circular orbit. Since TrES-1's eclipses have low signal-to-noise ratios, we implemented optimal photometry and differential-evolution Markov Chain Monte Carlo (MCMC) algorithms in our Photometry for Orbits, Eclipses, and Transits pipeline. Benefits include higher photometric precision and ∼10 times faster MCMC convergence, with better exploration of the phase space and no manual parameter tuning.

• OSTI ID: 22370046
• Journal Information: Astrophysical Journal, Vol. 797, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCURACY
ALGORITHMS
BRIGHTNESS
COMPUTERIZED SIMULATION
ECLIPSE
ELEMENT ABUNDANCE
EMISSION
EQUILIBRIUM
MARKOV PROCESS
MONTE CARLO METHOD
ORBITS
PHASE SPACE
PHOTOMETRY
RADIAL VELOCITY
SIGNAL-TO-NOISE RATIO
STAR EVOLUTION
STARS
TEMPERATURE INVERSIONS