Hot nights on extrasolar planets: mid‐infrared phase variations of hot Jupiters

By N. Cowan, E. Agol, D. Charbonneau. 2007

141 citations recorded by the source corpus.

We present results from Spitzer Space Telescope observations of the mid-infrared phase variations of three short-period extrasolar planetary systems: HD 209458, HD 179949 and 51 Peg. We gathered Infrared Array Camera (IRAC) images in multiple wavebands (3.6 or 4.5 and 8 μm) at eight phases of each planet's orbit. We find the uncertainty in relative photometry from one epoch to the next to be significantly larger than the photon counting error at 3.6 and 4.5 μm. We are able to place 2σ upper limits of only ∼2 per cent on the phase variations at these wavelengths. At 8 μm, the epoch-to-epoch systematic uncertainty is comparable to the photon counting noise and we detect a phase function for HD 179949 which is in phase with the planet's orbit and with a relative peak-to-trough amplitude of 0.001 41 (33). Assuming that HD 179949b has a radius R j < R p < 1.2R j , it must recirculate less than 21 per cent of incident stellar energy to its night side at the 1 σ level (less than 26 per cent at the 2σ level, where 50 per cent signifies full recirculation). If the planet has a small Bond albedo, it must have a mass less than 2.4M j (1σ). We do not detect phase variations for the other two systems but we do place the following 2σ upper limits: 0.0007 for 51 Peg and 0.0015 for HD 209458. Due to its edge-on configuration, the upper limit for HD 209458 translates, with appropriate assumptions about Bond albedo, into a lower limit on the recirculation occuring in the planet's atmosphere. HD 209458b must recirculate at least 32 per cent of incident stellar energy to its night side, at the 1σ level (at least 16 per cent at the 2σ level), which is consistent with other constraints on recirculation from the depth of secondary eclipse depth at 8 μm and the low optical albedo. These data indicate that different hot Jupiter planets may experience different recirculation efficiencies.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/aeae3317a44d3ef5cfe72e960227643ce67ac423

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In Astronomy and Astrophysics

1. Jon Fortney
2. N. Madhusudhan
3. A. Showman
4. M. Marley
5. H. Knutson
6. D. Deming
7. M. Line
8. D. Charbonneau

In Instrumentation

1. Jon Fortney
2. N. Madhusudhan
3. A. Showman
4. M. Marley
5. H. Knutson
6. M. Line
7. D. Deming
8. D. Charbonneau

Citations in the corpus

• A SYSTEMATIC RETRIEVAL ANALYSIS OF SECONDARY ECLIPSE SPECTRA. II. A UNIFORM ANALYSIS OF NINE PLANETS AND THEIR C TO O RATIOS (2013, methodology): “Multiple groups have obtained secondary eclipse observations using broadband photometry (Cowan et al. 2007; Knutson et al. 2008; Crossfield et al. 2012a), NICMOS spectroscopy (Swain et al. 2009b), and Spitzer IRS spectroscopy (Richardson et al. 2007; Swain et al. 2008).”
• ROTATION AND WINDS OF EXOPLANET HD 189733 b MEASURED WITH HIGH-DISPERSION TRANSMISSION SPECTROSCOPY (2015, background): “Other work either lacks the continuous phase coverage for assessing such a trend (Harrington et al. 2006; Cowan et al. 2007), or show no evidence for a displacement (Knutson et al. 2009a; Crossfield et al. 2012).”
• MULTIWAVELENGTH CONSTRAINTS ON THE DAY–NIGHT CIRCULATION PATTERNS OF HD 189733b (2008, background): “Both the observations by Harrington et al. (2006) and Cowan et al. (2007) are sparsely sampled, consisting of a series of brief visits with the Spitzer Space Telescope spread out over the planet’s orbit, and thus do not place any strong constraints on the timing of minima or maxima in the light…”
• ATMOSPHERIC HEAT REDISTRIBUTION ON HOT JUPITERS (2013, unknown): “Colored symbols with error bars are from published observations (Knutson et al. 2007, 2009a,b, 2012; Cowan et al. 2007, 2012; Borucki et al. 2009; Maxted et al. 2013).”
• Inverting Phase Functions to Map Exoplanets (2008, background): “The first successful observations of this sort were reported by Harrington et al. (2006), Knutson et al. (2007) and Cowan et al. (2007).”
• Design Considerations for a Ground-Based Transit Search for Habitable Planets Orbiting M Dwarfs (2007, background): “Most recently, infrared observations gathered at a variety of orbital phases have allowed the characterization of the longitudinal temperature profiles for several Hot Jupiters (Harrington et al. 2006; Knutson et al. 2007; Cowan et al. 2007).”
• 3.6 AND 4.5 μm PHASE CURVES AND EVIDENCE FOR NON-EQUILIBRIUM CHEMISTRY IN THE ATMOSPHERE OF EXTRASOLAR PLANET HD 189733b (2012, background): “…et al. 2009c), HD 80606b Laughlin et al. (2009), HAT-P-7b (Borucki et al. 2009; Welsh et al. 2010), CoRoT-1b (Snellen et al. 2009), and WASP-12b (Cowan et al. 2012), with more sparsely sampled phase curves for three additional planets (51 Peg b, HD 209458b, and HD 179949b) from Cowan et al. (2007).”
• Theoretical Spectral Models of the Planet HD 209458b with a Thermal Inversion and Water Emission Bands (2007, methodology): “…the direct detection of planetary atmospheres via lowresolution spectroscopy and precision IR photometry is now a reality (Charbonneau et al. 2005; Deming et al. 2005,2006,2007; Grillmair et al. 2007; Richardson et al. 2007; Harrington et al. 2006,2007; Knutson et al. 2007b,c; Cowan et al. 2007).”
• The 3.6-8.0 μm Broadband Emission Spectrum of HD 209458b: Evidence for an Atmospheric Temperature Inversion (2007, background): “Cowan et al. (2007) placed a 2σ upper limit of 0.0015 on the size of the phase variation for this planet at 8 µm; when compared to the eclipse depth of 0.00240± 0.00026 described in this paper, this indicates that the flux from the night side must be at least 60% of the flux from the day side,…”
• THE STATISTICS OF ALBEDO AND HEAT RECIRCULATION ON HOT EXOPLANETS (2009, background): “The uniform study presented in Cowan et al. (2007), on the other hand, showed that HD 179949b and HD 209458b exhibit significantly different degrees of heat recirculation, confirming suspicions.”
• ATMOSPHERIC CIRCULATION OF HOT JUPITERS: COUPLED RADIATIVE-DYNAMICAL GENERAL CIRCULATION MODEL SIMULATIONS OF HD 189733b and HD 209458b (2008, unknown): “From several briefSpitzer observations at different phases, Cowan et al. (2007) placed a 2-σ upper limit of 0.0015 on the peak-to-peak phase variation in the planet/star flux ratio at 8µm.”
• THERMAL PHASE VARIATIONS OF WASP-12b: DEFYING PREDICTIONS (2011, unknown): “Such observations have been made for non-transiting short-period planets (Cowan et al. 2007; Crossfield et al. 2010), but are most potent when combined with transit and eclipse observations for edge-on systems, because of the additional knowledge of the planet’s inclination, mass, and radius…”
• DISEQUILIBRIUM CARBON, OXYGEN, AND NITROGEN CHEMISTRY IN THE ATMOSPHERES OF HD 189733b AND HD 209458b (2011, background): “…lags (e.g., Knutson et al. 2007, 2009; Cooper & Showman 2006; Fortney et al. 2006a, 2008a, 2010; Richardson et al. 2007; Burrows et al. 2007, 2008; Cowan et al. 2007; Showman et al. 2008, 2009; Madhusudhan & Seager 2009, 2010a), and (4) the inferred presence of hazes, clouds, and Rayleigh…”
• THE CLIMATE OF HD 189733b FROM FOURTEEN TRANSITS AND ECLIPSES MEASURED BY SPITZER (2010, methodology): “We chose IRAC channel 4 (8 µm) as it has been demonstrated to be the most stable IRAC band (e.g. Cowan et al. 2007, and references therein).”
• Atmospheric Circulation of Hot Jupiters: Three-dimensional Circulation Models of HD 209458b and HD 189733b with Simplified Forcing (2008, unknown): “By lessening the predicted day-night flux variation, this disequilibrium effect allows us to fit the upper limit of 0.0015 on the peak-to-peak planet/star flux variation of HD209458b at 8 µ m (Cowan et al. 2007).”
• Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b (2014, methodology): “Cowan et al. (2007) observed the phase curve of HD 179949 with Spitzer/IRAC at 3.6 µm and 8.0 µm.”