scholarly journals Optical phase curve of the ultra-hot Jupiter WASP-121b

2020 ◽  
Vol 637 ◽  
pp. A36 ◽  
Author(s):  
V. Bourrier ◽  
D. Kitzmann ◽  
T. Kuntzer ◽  
V. Nascimbeni ◽  
M. Lendl ◽  
...  
Keyword(s):  
Emission Spectrum ◽  
Heat Transport ◽  
Temperature Inversion ◽  
Phase Curve ◽  
Optical Photometry ◽  
Optical Phase ◽  
Strong Deviation ◽  
Hot Jupiter

We present the analysis of TESS optical photometry of WASP-121b, which reveals the phase curve of this transiting ultra-hot Jupiter. Its hotspot is located at the sub-stellar point, showing inefficient heat transport from the dayside (2870 ± 50 K) to the nightside (<2500 K at 3σ) at the altitudes probed by TESS. The TESS eclipse depth, measured at the shortest wavelength to date for WASP-121b, confirms the strong deviation from blackbody planetary emission. Our atmospheric retrieval on the complete emission spectrum supports the presence of a temperature inversion, which can be explained by the presence of VO and possibly TiO and FeH. The strong planetary emission at short wavelengths could arise from an H− continuum.

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

2008 ◽  
Vol 4 (S253) ◽  
pp. 255-261
Author(s):  
Heather A. Knutson
Keyword(s):  
Emission Spectrum ◽  
Inversion Layer ◽  
Emission Spectra ◽  
Phase Curve ◽  
Hot Jupiters ◽  
Thermal Phase ◽  
Additional Support ◽  
Temperature Inversions ◽  
The Relationship ◽  
Hot Jupiter

AbstractWe 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.

scholarly journals The ultra-hot-Jupiter KELT-16 b: Dynamical Evolution and Atmospheric Properties

2021 ◽  
Author(s):  
L Mancini ◽  
J Southworth ◽  
L Naponiello ◽  
Ö Baştürk ◽  
D Barbato ◽  
...  
Keyword(s):  
Lower Limit ◽  
Broad Band ◽  
Flux Ratio ◽  
Dynamical Evolution ◽  
Emission Spectra ◽  
Temperature Inversion ◽  
Period Change ◽  
Phase Curve ◽  
Night Side ◽  
Hot Jupiter

Abstract We present broad-band photometry of 30 planetary transits of the ultra-hot Jupiter KELT-16 b, using five medium-class telescopes. The transits were monitored through standard B, V, R, I filters and four were simultaneously observed from different places, for a total of 36 new light curves. We used these new photometric data and those from the TESS space telescope to review the main physical properties of the KELT-16 planetary system. Our results agree with previous measurements but are more precise. We estimated the mid-transit times for each of these transits and combined them with others from the literature to obtain 69 epochs, with a time baseline extending over more than four years, and searched for transit time variations. We found no evidence for a period change, suggesting a lower limit for orbital decay at 8 Myr, with a lower limit on the reduced tidal quality factor of $Q^{\prime }_{\star }&gt;(1.9 \pm 0.8) \times 10^5$ with $95\%$ confidence. We built up an observational, low-resolution transmission spectrum of the planet, finding evidence of the presence of optical absorbers, although with a low significance. Using TESS data, we reconstructed the phase curve finding that KELT-16 b has a phase offset of 25.25 ± 14.03 ○E, a day- and night-side brightness temperature of 3190 ± 61 K and 2668 ± 56 K, respectively. Finally, we compared the flux ratio of the planet over its star at the TESS and Spitzer wavelengths with theoretical emission spectra, finding evidence of a temperature inversion in the planet’s atmosphere, the chemical composition of which is preferably oxygen-rich rather than carbon-rich.

scholarly journals SPECTROSCOPIC EVIDENCE FOR A TEMPERATURE INVERSION IN THE DAYSIDE ATMOSPHERE OF HOT JUPITER WASP-33b

2015 ◽  
Vol 806 (2) ◽  
pp. 146 ◽  
Author(s):  
Korey Haynes ◽  
Avi M. Mandell ◽  
Nikku Madhusudhan ◽  
Drake Deming ◽  
Heather Knutson
Keyword(s):  
Temperature Inversion ◽  
Spectroscopic Evidence ◽  
Hot Jupiter

scholarly journals The Hubble WFC3 Emission Spectrum of the Extremely Hot Jupiter KELT-9b

2021 ◽  
Vol 907 (1) ◽  
pp. L22
Author(s):  
Quentin Changeat ◽  
Billy Edwards
Keyword(s):  
Emission Spectrum ◽  
Hot Jupiter

scholarly journals Stellar impact on disequilibrium chemistry and observed spectra of hot Jupiter atmospheres

2020 ◽  
Vol 639 ◽  
pp. A48 ◽  
Author(s):  
D. Shulyak ◽  
L. M. Lara ◽  
M. Rengel ◽  
N.-E. Nèmec
Keyword(s):  
Extreme Ultraviolet ◽  
Chemical Species ◽  
Pressure Profile ◽  
Temperature Inversion ◽  
Chemical Kinetic ◽  
Mixing Ratio ◽  
Stellar Activity ◽  
Hot Jupiters ◽  
The Impact ◽  
Hot Jupiter

Aims. We study the effect of disequilibrium processes (photochemistry and vertical transport) on mixing ratio profiles of neutral species and on the simulated spectra of a hot Jupiter exoplanet that orbits stars of various spectral types. We additionally address the impact of stellar activity that should be present, to various degrees, in all stars with convective envelopes. Methods. We used the VULCAN chemical kinetic code to compute number densities of species in irradiated planetary atmospheres. The temperature-pressure profile of the atmosphere was computed with the HELIOS code. We also utilized the τ-REx forward model to predict the spectra of planets in primary and secondary eclipses. In order to account for the stellar activity, we made use of the observed solar extreme ultraviolet (XUV) spectrum taken from Virtual Planetary Laboratory as a proxy for an active sun-like star. Results. We find large changes in the mixing ratios of most chemical species in planets orbiting A-type stars, which radiate strong XUV flux thereby inducing a very effective photodissociation. For some species, these changes can propagate very deep into the planetary atmosphere to pressures of around 1 bar. To observe disequilibrium chemistry we favor hot Jupiters with temperatures Teq = 1000 K and ultra-hot Jupiters, with Teq ≈ 3000 K,which also have temperature inversion in their atmospheres. On the other hand, disequilibrium calculations predict no noticeable changes in spectra of planets with intermediate temperatures. We also show that stellar activity similar to that of the modern Sun drives important changes in mixing ratio profiles of atmospheric species. However, these changes take place at very high atmospheric altitudes and thus do not affect predicted spectra. Finally, we estimate that the effect of disequilibrium chemistry in planets orbiting nearby bright stars could be robustly detected and studied with future missions with spectroscopic capabilities in infrared such as James Webb Space Telescope and ARIEL.

scholarly journals Probing exoplanet clouds with optical phase curves

2015 ◽  
Vol 112 (44) ◽  
pp. 13461-13466 ◽  
Author(s):  
Antonio García Muñoz ◽  
Kate G. Isaak
Keyword(s):  
General Circulation ◽  
Model Fitting ◽  
Giant Planet ◽  
General Circulation Models ◽  
Phase Curve ◽  
Optical Phase ◽  
Orbital Phase ◽  
Study Case ◽  
Synthetic Phase ◽  
Unique Study

Kepler-7b is to date the only exoplanet for which clouds have been inferred from the optical phase curve—from visible-wavelength whole-disk brightness measurements as a function of orbital phase. Added to this, the fact that the phase curve appears dominated by reflected starlight makes this close-in giant planet a unique study case. Here we investigate the information on coverage and optical properties of the planet clouds contained in the measured phase curve. We generate cloud maps of Kepler-7b and use a multiple-scattering approach to create synthetic phase curves, thus connecting postulated clouds with measurements. We show that optical phase curves can help constrain the composition and size of the cloud particles. Indeed, model fitting for Kepler-7b requires poorly absorbing particles that scatter with low-to-moderate anisotropic efficiency, conclusions consistent with condensates of silicates, perovskite, and silica of submicron radii. We also show that we are limited in our ability to pin down the extent and location of the clouds. These considerations are relevant to the interpretation of optical phase curves with general circulation models. Finally, we estimate that the spherical albedo of Kepler-7b over the Kepler passband is in the range 0.4–0.5.

scholarly journals The 3.6–8.0 μm Broadband Emission Spectrum of HD 209458b: Evidence for an Atmospheric Temperature Inversion

2008 ◽  
Vol 673 (1) ◽  
pp. 526-531 ◽  
Author(s):  
Heather A. Knutson ◽  
David Charbonneau ◽  
Lori E. Allen ◽  
Adam Burrows ◽  
S. Thomas Megeath
Keyword(s):  
Emission Spectrum ◽  
Temperature Inversion ◽  
Atmospheric Temperature ◽  
Broadband Emission

scholarly journals THE 4.5 μm FULL-ORBIT PHASE CURVE OF THE HOT JUPITER HD 209458b

2014 ◽  
Vol 790 (1) ◽  
pp. 53 ◽  
Author(s):  
Robert T. Zellem ◽  
Nikole K. Lewis ◽  
Heather A. Knutson ◽  
Caitlin A. Griffith ◽  
Adam P. Showman ◽  
...  
Keyword(s):  
Phase Curve ◽  
Hot Jupiter

scholarly journals Thermal Phase Curves of XO-3b: An Eccentric Hot Jupiter at the Deuterium Burning Limit

2021 ◽  
Vol 163 (1) ◽  
pp. 32
Author(s):  
Lisa Dang ◽  
Taylor J. Bell ◽  
Nicolas B. Cowan ◽  
Daniel Thorngren ◽  
Tiffany Kataria ◽  
...  
Keyword(s):  
Energy Balance ◽  
Wind Speed ◽  
Mixed Layer ◽  
Energy Balance Model ◽  
Phase Curve ◽  
Balance Model ◽  
Model Predictions ◽  
M Phase ◽  
Averaged Model ◽  
Hot Jupiter

Abstract We report Spitzer full-orbit phase observations of the eccentric hot Jupiter XO-3b at 3.6 and 4.5 μm. Our new eclipse depth measurements of 1770 ± 180 ppm at 3.6 μm and 1610 ± 70 ppm at 4.5 μm show no evidence of the previously reported dayside temperature inversion. We also empirically derive the mass and radius of XO-3b and its host star using Gaia DR3's parallax measurement and find a planetary mass M p = 11.79 ± 0.98 M Jup and radius R p = 1.295 ± 0.066 R Jup. We compare our Spitzer observations with multiple atmospheric models to constrain the radiative and advective properties of XO-3b. While the decorrelated 4.5 μm observations are pristine, the 3.6 μm phase curve remains polluted with detector systematics due to larger amplitude intrapixel sensitivity variations in this channel. We focus our analysis on the more reliable 4.5 μm phase curve and fit an energy balance model with solid body rotation to estimate the zonal wind speed and the pressure of the bottom of the mixed layer. Our energy balance model fit suggests an eastward equatorial wind speed of 3.13 − 0.83 + 0.26 km s−1, an atmospheric mixed layer down to 2.40 − 0.16 + 0.92 bars, and a Bond albedo of 0.106 − 0.106 + 0.008 . We assume that the wind speed and mixed layer depth are constant throughout the orbit. We compare our observations with 1D planet-averaged model predictions at apoapse and periapse and 3D general circulation model predictions for XO-3b. We also investigate the inflated radius of XO-3b and find that it would require an unusually large amount of internal heating to explain the observed planetary radius.

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