Spitzer IRAC Secondary Eclipse Photometry of the Transiting Extrasolar Planet HAT-P-1b

Abstract

We report Spitzer/IRAC photometry of the transiting giant exoplanet HAT-P-1b during its secondary eclipse. This planet lies near the postulated boundary between the pM and pL-class of hot Jupiters, and is important as a test of models for temperature inversions in hot Jupiter atmospheres. We derive eclipse depths for HAT-P-1b, in units of the stellar flux, that are: 0.080% +/- 0.008%,[3.6um], 0.135% +/- 0.022%,[4.5um],0.203% +/- 0.031%,[5.8um], and $0.238% +/- 0.040%,[8.0um]. These values are best fit using an atmosphere with a modest temperature inversion, intermediate between the archetype inverted atmosphere (HD209458b) and a model without an inversion. The observations also suggest that this planet is radiating a large fraction of the available stellar irradiance on its dayside, with little available for redistribution by circulation. This planet has sometimes been speculated to be inflated by tidal dissipation, based on its large radius in discovery observations, and on a non-zero orbital eccentricity allowed by the radial velocity data. The timing of the secondary eclipse is very sensitive to orbital eccentricity, and we find that the central phase of the eclipse is 0.4999 +/- 0.0005. The difference between the expected and observed phase indicates that the orbit is close to circular, with a 3-sigma limit of |e cosw| < 0.002.

5 pages, 6 figures, 1 table. Accepted by The Astrophysical Journal, 10 Nov 2009

References in corpus (18)

• Detection of Thermal Emission from an Extrasolar Planet
• Improved parameters for extrasolar transiting planets
• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• Atmospheric Sulfur Photochemistry on Hot Jupiters
• The Broadband Infrared Emission Spectrum of the Exoplanet HD 189733b
• Theoretical Spectra and Light Curves of Close-in Extrasolar Giant Planets and Comparison with Data
• Theoretical Spectral Models of the Planet HD 209458b with a Thermal Inversion and Water Emission Bands
• HAT-P-1b: A Large-Radius, Low-Density Exoplanet Transiting one Member of a Stellar Binary
• Strong Infrared Emission from the Extrasolar Planet HD189733b
• Search for Carbon Monoxide in the atmosphere of the Transiting Exoplanet HD189733b
• Spitzer Transit and Secondary Eclipse Photometry of GJ 436b
• Thermal Emission of Exoplanet XO-1b
• The Transit Light Curve Project. VII. The Not-So-Bloated Exoplanet HAT-P-1b
• A Sensitive Search for Variability in Late L Dwarfs: The Quest for Weather
• On the Presence of Water and Global Circulation in the Transiting Planet HD 189733b
• Characterization of the hot Neptune GJ 436b with Spitzer and ground-based observations
• Detection of Thermal Emission of XO-2b: Evidence for a Weak Temperature Inversion
• Measurement of the Spin-Orbit Angle of Exoplanet HAT-P-1b

Cited by in corpus (45)

• Exoplanet Atmospheres
• The Statistics of Albedo and Heat Recirculation on Hot Exoplanets
• The climate of HD 189733b from fourteen transits and eclipses measured by Spitzer
• 3.6 and 4.5 Micron Phase Curves and Evidence for Non-Equilibrium Chemistry in the Atmosphere of Extrasolar Planet HD 189733b
• A Correlation Between Stellar Activity and Hot Jupiter Emission Spectra
• HST hot Jupiter Transmission Spectral Survey: A detection of Na and strong optical absorption in HAT-P-1b
• The atmospheric circulation of a nine-hot Jupiter sample: Probing circulation and chemistry over a wide phase space
• Pseudo 2D chemical model of hot Jupiter atmospheres: application to HD 209458b and HD 189733b
• A Spitzer Transmission Spectrum for the Exoplanet GJ 436b, Evidence for Stellar Variability, and Constraints on Dayside Flux Variations
• Hubble Space Telescope hot Jupiter Transmission Spectral Survey: detection of water in HAT-P-1b from Wide Field Camera 3 near-infrared spatial scan observations
• Deciphering the Atmospheric Composition of WASP-12b: A Comprehensive Analysis of its Dayside Emission
• Ground-based near-UV observations of 15 transiting exoplanets: Constraints on their atmospheres and no evidence for asymmetrical transits
• Features in the Broadband Eclipse Spectra of Exoplanets: Signal or Noise?
• Near-Infrared Thermal Emission from the Hot Jupiter TrES-2b: Ground-Based Detection of the Secondary Eclipse
• Warm Spitzer Photometry of the Transiting Exoplanets CoRoT-1 and CoRoT-2 at Secondary Eclipse
• Searching for Thermal Inversion Agents in the Transmission Spectrum of MASCARA-2b/KELT-20b: Detection of Neutral Iron and Ionised Calcium H$\&$K Lines
• Warm Spitzer Photometry of XO-4b, HAT-P-6b and HAT-P-8b
• A temperature inversion with atomic iron in the ultra-hot dayside atmosphere of WASP-189b
• A transition between the hot and the ultra-hot Jupiter atmospheres
• Updated Spitzer Emission Spectroscopy of Bright Transiting Hot Jupiter HD189733b
• Identifying new opportunities for exoplanet characterisation at high spectral resolution
• Warm Spitzer Photometry of Three Hot Jupiters: HAT-P-3b, HAT-P-4b and HAT-P-12b
• Secondary eclipse observations for seven hot-Jupiters from the Anglo-Australian Telescope
• The atmospheres of the hot-Jupiters Kepler-5b and Kepler-6b observed during occultations with Warm-Spitzer and Kepler
• Thermal Emission and Tidal Heating of the Heavy and Eccentric Planet XO-3b
• Evidence for disequilibrium chemistry from vertical mixing in hot Jupiter atmospheres. A comprehensive survey of transiting close-in gas giant exoplanets with warm-Spitzer/IRAC
• The Dawes Review 3: The Atmospheres of Extrasolar Planets and Brown Dwarfs
• From cold to hot irradiated gaseous exoplanets: Toward an observation-based classification scheme
• Optical transmission photometry of the highly inflated exoplanet WASP-17b
• GTC OSIRIS transiting exoplanet atmospheric survey: detection of potassium in HAT-P-1b from narrowband spectrophotometry
• Colour-magnitude diagrams of transiting Exoplanets - II. A larger sample from photometric distances
• The GROUSE project II: Detection of the Ks-band secondary eclipse of exoplanet HAT-P-1b
• Further constraints on the optical transmission spectrum of HAT-P-1b
• Phase curve pollution of exoplanet transmission spectra
• Thermal emission from WASP-24b at 3.6 and 4.5 μm
• Relative photometry of HAT-P-1b occultations
• Characterization of Exoplanets: Secondary Eclipses
• Ground-based optical transmission spectrum of the hot Jupiter HAT-P-1b
• Hot exoplanetary atmospheres in 3D
• Trends in Spitzer Secondary Eclipses
• Detection of Na and K in the atmosphere of the hot Jupiter HAT-P-1b with P200/DBSP
• Warm Spitzer Occultation Photometry of WASP-26b at 3.6μm and 4.5μm
• Colour-colour and colour-magnitude diagrams for Hot Jupiters
• Reassessing Exoplanet Light Curves with a Thermal Model
• Precision Time-series Photometry in the Thermal Infrared with a 'Wall-Eyed' Pointing Mode at the Large Binocular Telescope