The Phase-Dependent Infrared Brightness of the Extrasolar Planet ʊ Andromedae b

Abstract. We present new observations of the emission spectrum of the hot Jupiter TrES-4 designed to test the theory that the presence of temperature inversions in the atmospheres of these planets are correlated with the amount of radiation received by the planet. Our observations reveal that TrES-4 has an emission spectrum similar to that of HD 209458b, which requires the presence of an inversion layer high in the atmosphere and water emission bands in order to explain the observed features, providing additional support for that theory. We also present new observations of the thermal phase curve of HD 189733b at 24 μm, which we combine with our previous observations at 8 μm to examine how circulation in this planet's atmosphere varies as a function of depth. We discuss the relationship between the strength of the day-night circulation on both planets and their other observable properties, in particular their emission spectra.

Section: μM Phase Curve For Hd 189733bmentioning

confidence: 99%

Characterizing the Atmospheres of Hot Jupiters: From Spectra to Multi-Color Maps

Knutson

2008

“…We note that the relatively homogenized atmospheric temperatures of HD 189733b , contrasted with the large day/night contrasts of HD 179949b (Cowan et al 2007) and υ And b (Harrington et al 2006) seem to reinforce the connection between temperature inversions and larger day/night contrasts. Additional light curve data will be important.…”

mentioning

confidence: 99%

Two Classes of Hot Jupiter Atmospheres

Fortney¹

2008

Abstract. We highlight the potential importance of gaseous TiO and VO opacity on the highly irradiated close-in giant planets. The day-side atmospheres of these planets may naturally fall into two classes that are somewhat analogous to the M-and L-type dwarfs. Those that are warm enough to have appreciable opacity due to TiO and VO gases we term the "pM Class" planets, and those that are cooler, such that Ti and V are predominantly in solid condensates, we term "pL Class" planets. The optical spectra of pL Class planets are dominated by neutral atomic Na and K absorption. We discuss a connection between temperature inversions and large day/night temperature contrasts for the pM Class planets. Around a Sun-like primary, for solar composition, this boundary likely occurs at ∼0.04-0.05 AU, but we discuss important uncertainties. The difference in the observed day/night contrast between υ And b (pM Class) and HD 189733b (pL Class) is naturally explained in this scenario.

“…In addition to primary transit measurements (Charbonneau et al 2000), these tools include secondary eclipse (Deming et al 2005), differential spectroscopy , phase-curve monitoring (Harrington et al 2006, Cowan et al 2007, Doppler absorption spectroscopy (Snellen et al 2010), and transmission spectra . These observations have motivated many groups to study the atmospheric dynamics of these planets and its role in both redistributing incident stellar energy throughout the atmosphere and (potentially) in influencing the overall evolution of the interior.…”

Section: Introductionmentioning

confidence: 99%

3D Models of Exoplanet Atmospheres

Dobbs-Dixon¹

2011

Abstract. Dynamical models of strongly irradiated gas-giant atmospheres exhibit a range of behavior, the nature of which depends on both the adopted parameters and the adopted numerical model. Discerning the correct choice of physical parameters and modeling philosophy can be difficult. Here, I present a series of wavelength-dependent transmission spectra for the giant planet HD209458b based on 3D radiative hydrodynamical models for a range of kinematic viscosities. While flow patterns and temperature distributions can vary significantly, disk-averaged phase curves mask much of this information. Transmission spectra, on the other hand, probe the day-night transition where advective contributions dominate and differences are often most pronounced. Transmission spectra illustrate noticeable changes, especially when comparing the differences between transmission spectra of eastern and western hemispheres, as might be seen during ingress and egress.