scholarly journals An optical transmission spectrum of the ultra-hot Jupiter WASP-33 b

2019 ◽  
Vol 622 ◽  
pp. A71 ◽  
Author(s):  
C. von Essen ◽  
M. Mallonn ◽  
L. Welbanks ◽  
N. Madhusudhan ◽  
A. Pinhas ◽  
...  
Keyword(s):  
Light Curves ◽  
Atmospheric Composition ◽  
Data Sets ◽  
Hot Jupiters ◽  
High Data ◽  
Trace Species ◽  
Exoplanetary Atmospheres ◽  
Combined Data ◽  
Hot Jupiter

There has been increasing progress toward detailed characterization of exoplanetary atmospheres, in both observations and theoretical methods. Improvements in observational facilities and data reduction and analysis techniques are enabling increasingly higher quality spectra, especially from ground-based facilities. The high data quality also necessitates concomitant improvements in models required to interpret such data. In particular, the detection of trace species such as metal oxides has been challenging. Extremely irradiated exoplanets (~3000 K) are expected to show oxides with strong absorption signals in the optical. However, there are only a few hot Jupiters where such signatures have been reported. Here we aim to characterize the atmosphere of the ultra-hot Jupiter WASP-33 b using two primary transits taken 18 orbits apart. Our atmospheric retrieval, performed on the combined data sets, provides initial constraints on the atmospheric composition of WASP-33 b. We report a possible indication of aluminum oxide (AlO) at 3.3-σ significance. The data were obtained with the long slit OSIRIS spectrograph mounted at the 10-m Gran Telescopio Canarias. We cleaned the brightness variations from the light curves produced by stellar pulsations, and we determined the wavelength-dependent variability of the planetary radius caused by the atmospheric absorption of stellar light. A simultaneous fit to the two transit light curves allowed us to refine the transit parameters, and the common wavelength coverage between the two transits served to contrast our results. Future observations with HST as well as other large ground-based facilities will be able to further constrain the atmospheric chemical composition of the planet.

Exoplanets: Atmospheres of Hot Jupiters

2019 ◽  
Author(s):  
Dmitry V. Bisikalo ◽  
Pavel V. Kaygorodov ◽  
Valery I. Shematovich
Keyword(s):  
Solar System ◽  
Alternative Hypothesis ◽  
Atmospheric Composition ◽  
Current Status ◽  
Hot Jupiters ◽  
History Of ◽  
Exoplanetary Atmospheres ◽  
Host Stars ◽  
Gaseous Envelopes ◽  
Hot Jupiter

The history of exoplanetary atmospheres studies is strongly based on the observations and investigations of the gaseous envelopes of hot Jupiters—exoplanet gas giants that have masses comparable to the mass of Jupiter and orbital semi-major axes shorter than 0.1 AU. The first exoplanet around a solar-type star was a hot Jupiter discovered in 1995. Researchers found an object that had completely atypical parameters compared to planets known in the solar system. According to their estimates, the object might have a mass about a half of the Jovian mass and a very short orbital period (four days), which means that it has an orbit roughly corresponding to the orbit of Mercury. Later, many similar objects were discovered near different stars, and they acquired a common name—hot Jupiters. It is still unclear what the mechanism is for their origin, because generally accepted theories of planetary evolution predict the formation of giant planets only at large orbital distances, where they can accrete enough matter before the protoplanetary disc disappears. If this is true, before arriving at such low orbits, hot Jupiters might have a long migration path, caused by interactions with other massive planets and/or with the gaseous disc. In favor of this model is the discovery of many hot Jupiters in elliptical and highly inclined orbits, but on the other hand several observed hot Jupiters have circular orbits with low inclination. An alternative hypothesis is that the cores of future hot Jupiters are super-Earths that may later intercept matter from the protoplanetary disk falling on the star. The scientific interest in hot Jupiters has two aspects. The first is the peculiarity of these objects: they have no analogues in the solar system. The second is that, until recently, only for hot Jupiters was it possible to obtain observational characteristics of their atmospheres. Many of the known hot Jupiters are eclipsing their host stars, so, from their light curve and spectral data obtained during an eclipse, it became possible to obtain information about their shape and their atmospheric composition. Thus it is possible to conclude that hot Jupiters are a common type of exoplanet, having no analogues in the solar system. Many aspects of their evolution and internal structure remain unclear. Being very close to their host stars, hot Jupiters must interact with the stellar wind and stellar magnetic field, as well as with stellar flares and coronal mass ejections, allowing researchers to gather information about them. According to UV observations, at least a fraction of hot Jupiters have extended gaseous envelopes, extending far beyond of their upper atmospheres. The envelopes are observable with current astronomical instruments, so it is possible to develop their astrophysical models. The history of hot Jupiter atmosphere studies during the past 20 years and the current status of modern theories describing the extended envelopes of hot Jupiters are excellent examples of the progress in understanding planetary atmospheres formation and evolution both in the solar system and in the extrasolar planetary systems.

scholarly journals Tidally induced stellar oscillations: converting modelled oscillations excited by hot Jupiters into observables

2020 ◽  
Vol 500 (2) ◽  
pp. 2711-2731
Author(s):  
Andrew Bunting ◽  
Caroline Terquem
Keyword(s):  
Radial Velocity ◽  
Orbital Period ◽  
Planetary Systems ◽  
Velocity Signal ◽  
Convective Flux ◽  
Hot Jupiters ◽  
Stellar Oscillations ◽  
Orbital Periods ◽  
Hot Jupiter

ABSTRACT We calculate the conversion from non-adiabatic, non-radial oscillations tidally induced by a hot Jupiter on a star to observable spectroscopic and photometric signals. Models with both frozen convection and an approximation for a perturbation to the convective flux are discussed. Observables are calculated for some real planetary systems to give specific predictions. The photometric signal is predicted to be proportional to the inverse square of the orbital period, P−2, as in the equilibrium tide approximation. However, the radial velocity signal is predicted to be proportional to P−1, and is therefore much larger at long orbital periods than the signal corresponding to the equilibrium tide approximation, which is proportional to P−3. The prospects for detecting these oscillations and the implications for the detection and characterization of planets are discussed.

scholarly journals WASP-180Ab: Doppler tomography of a hot Jupiter orbiting the primary star in a visual binary

2019 ◽  
Vol 490 (2) ◽  
pp. 2467-2474
Author(s):  
L Y Temple ◽  
C Hellier ◽  
D R Anderson ◽  
K Barkaoui ◽  
F Bouchy ◽  
...  
Keyword(s):  
Binary Systems ◽  
Rotation Speed ◽  
Small Sample ◽  
Primary Star ◽  
Doppler Tomography ◽  
Companion Star ◽  
Hot Jupiters ◽  
Rotational Modulation ◽  
Hot Jupiter

ABSTRACT We report the discovery and characterization of WASP-180Ab, a hot Jupiter confirmed by the detection of its Doppler shadow and by measuring its mass using radial velocities. We find the 0.9  ±  0.1 MJup, 1.24  ±  0.04 RJup planet to be in a misaligned, retrograde orbit around an F7 star with Teff  =  6500 K and a moderate rotation speed of vsin i⋆  =  19.9 km s−1. The host star is the primary of a V  =  10.7 binary, where a secondary separated by ∼5 arcsec (∼1200 au) contributes ∼ 30 per cent of the light. WASP-180Ab therefore adds to a small sample of transiting hot Jupiters known in binary systems. A 4.6-d modulation seen in the WASP data is likely to be the rotational modulation of the companion star, WASP-180B.

scholarly journals Following the TraCS of exoplanets with Pan-Planets: Wendelstein-1b and Wendelstein-2b

2020 ◽  
Vol 639 ◽  
pp. A130
Author(s):  
C. Obermeier ◽  
J. Steuer ◽  
H. Kellermann ◽  
R. P. Saglia ◽  
Th. Henning ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Radial Velocity ◽  
Thermal Emission ◽  
Dwarf Star ◽  
Statistical Characterization ◽  
Hot Jupiters ◽  
Eclipse Observations ◽  
Short Period ◽  
Hot Jupiter

Hot Jupiters seem to get rarer with decreasing stellar mass. The goal of the Pan-Planets transit survey was the detection of such planets and a statistical characterization of their frequency. Here, we announce the discovery and validation of two planets found in that survey, Wendelstein-1b and Wendelstein-2b, which are two short-period hot Jupiters that orbit late K host stars. We validated them both by the traditional method of radial velocity measurements with the HIgh Resolution Echelle Spectrometer and the Habitable-zone Planet Finder instruments and then by their Transit Color Signature (TraCS). We observed the targets in the wavelength range of 4000−24 000 Å and performed a simultaneous multiband transit fit and additionally determined their thermal emission via secondary eclipse observations. Wendelstein-1b is a hot Jupiter with a radius of 1.0314−0.0061+0.0061 RJ and mass of 0.592−0.129+0.0165 MJ, orbiting a K7V dwarf star at a period of 2.66 d, and has an estimated surface temperature of about 1727−90+78 K. Wendelstein-2b is a hot Jupiter with a radius of 1.1592−0.0210+0.0204 RJ and a mass of 0.731−0.311+0.0541 MJ, orbiting a K6V dwarf star at a period of 1.75 d, and has an estimated surface temperature of about 1852−140+120 K. With this, we demonstrate that multiband photometry is an effective way of validating transiting exoplanets, in particular for fainter targets since radial velocity follow-up becomes more and more costly for those targets.

scholarly journals ACE-FTS measurements of trace species in the characterization of biomass burning plumes

2011 ◽  
Vol 11 (6) ◽  
pp. 16611-16637 ◽  
Author(s):  
K. A. Tereszchuk ◽  
G. González Abad ◽  
C. Clerbaux ◽  
D. Hurtmans ◽  
P.-F. Coheur ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Atmospheric Chemistry ◽  
Atmospheric Composition ◽  
Emission Region ◽  
Free Troposphere ◽  
Airborne Measurements ◽  
Convective Processes ◽  
Trace Species ◽  
Chemistry Experiment

Abstract. To further our understanding of the effects of biomass burning emission on atmospheric composition, we report measurements of trace species from biomass burning plumes made by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) instrument on the SCISAT-1 satellite. An extensive set of 15 molecules, C2H2, C2H6, CH3OH, CH4, CO, H2CO, HCN, HCOOH, HNO3, NO, NO2, N2O5, O3, OCS and SF6 are used in our analysis. Even though most biomass burning smoke is typically confined to the boundary layer, much of these emissions are injected directly into the free troposphere via fire-related convective processes and transported away from the emission region. Further knowledge of the aging of biomass burning emission in the free troposphere is needed. Tracer-tracer correlations are made between known pyrogenic species in these plumes in an effort to classify them and follow their chemical evolution. Criteria such as age and type of biomass material burned are considered. Emission factors are derived and compared to airborne measurements of biomass burning from numerous ecosystems to validate the ACE-FTS data.

New models of Jupiter in the context of Juno and Galileo: signature of a decoupling between the atmosphere and the interior

2020 ◽  
Author(s):  
Florian Debras ◽  
Gilles Chabrier
Keyword(s):  
Extrasolar Planets ◽  
Convective Zone ◽  
Giant Planets ◽  
Atmospheric Composition ◽  
Observational Constraints ◽  
Physical Processes ◽  
Hot Jupiters ◽  
Formation And Evolution ◽  
Gas Accretion

<p><span lang="en-US">Juno's observations of Jupiter's gravity field have revealed extremely low values for the gravitational moments that are difficult to reconcile with the high abundance of metals observed in the atmosphere by Galileo. Recent studies chose to arbitrarily get rid of one of these two constraints in order to build models of Jupiter.</span></p> <p><span lang="en-US">In this presentation, I will detail our new Jupiter structure models reconciling Juno and Galileo observational constraints. These models confirm the need to separate Jupiter into at least 4 layers: an outer convective shell, a non-convective zone of compositional change, an inner convective shell and a diluted core representing about 60 percent of the planet in radius. Compared to other studies, these models propose a new idea with important consequences: a decrease in the quantity of metals between the outer and inner convective shells. This would imply that the atmospheric composition is not representative of the internal composition of the planet, contrary to what is regularly admitted, and would strongly impact the Jupiter formation scenarios (localization, migration, accretion).</span></p> <p><span lang="en-US">In particular, the presence of an internal non-convective zone prevents mixing between the two convective envelopes. I will detail the physical processes of this semi-convective zone (layered convection or H-He immiscibility) and explain how they may persist during the evolution of the planet.</span></p> <p><span lang="en-US">These models also impose a limit mass on the compact core, which cannot be heavier than 5 Earth masses. Such a mass, lower than the runaway gas accretion minimum mass, needs to be explained in the light of our understanding of the formation and evolution of giant planets.</span></p> <p><span lang="en-US">Using these models of Jupiter, I will finally detail the application of our new understanding of the interior of this planet to giant exoplanets. At a time of direct imaging of extrasolar planets and atmospheric characterization of hot Jupiters, a good understanding of the internal processes of planets in the solar system is paramount to make the best use of all the observations.</span></p>

scholarly journals Future Observations of Transits and Light Curves from Space

2008 ◽  
Vol 4 (S253) ◽  
pp. 319-328 ◽  
Author(s):  
Charles A. Beichman ◽  
Tom Greene ◽  
John Krist
Keyword(s):  
Thermal Structure ◽  
Light Curves ◽  
Atmospheric Composition ◽  
Light Curve Analysis ◽  
James Webb Space Telescope ◽  
Sky Survey ◽  
Future Space ◽  
Host Stars

AbstractA variety of new observational opportunities have made transit and more generally light curve analysis central to the study of exoplanets. Talks at this IAU 253 Symposium have dramatically highlighted the measurement of the radius, density, atmospheric composition and atmospheric thermal structure, presently for relatively large, hot planets, but soon for smaller planets orbiting further from their host stars. On-going and future space observations will play a key role in the detection and characterization of these planetary systems. After a brief review, I focus on two topics: the need for a sensitive all-sky survey for planets transiting the brightest, closest stars and the follow-up opportunities afforded by the James Webb Space Telescope (JWST).

scholarly journals An enhanced slope in the transmission spectrum of the hot Jupiter WASP-104b

2020 ◽  
Vol 500 (4) ◽  
pp. 5420-5435
Author(s):  
G Chen ◽  
E Pallé ◽  
H Parviainen ◽  
H Wang ◽  
R van Boekel ◽  
...  
Keyword(s):  
Transmission Spectrum ◽  
Optical Transmission ◽  
Optical Transmission Spectrum ◽  
Light Curves ◽  
Physical Origin ◽  
Detailed Characterization ◽  
Companion Star ◽  
System Parameters ◽  
Hot Jupiter

ABSTRACT We present the optical transmission spectrum of the hot Jupiter WASP-104b based on one transit observed by the blue and red channels of the Double Spectrograph (DBSP) at the Palomar 200-inch telescope and 14 transits observed by the MuSCAT2 four-channel imager at the 1.52-m Telescopio Carlos Sánchez. We also analyse 45 additional K2 transits, after correcting for the flux contamination from a companion star. Together with the transit light curves acquired by DBSP and MuSCAT2, we are able to revise the system parameters and orbital ephemeris, confirming that no transit timing variations exist. Our DBSP and MuSCAT2 combined transmission spectrum reveals an enhanced slope at wavelengths shorter than 630 nm and suggests the presence of a cloud deck at longer wavelengths. While the Bayesian spectral retrieval analyses favour a hazy atmosphere, stellar spot contamination cannot be completely ruled out. Further evidence, from transmission spectroscopy and detailed characterization of the host star’s activity, is required to distinguish the physical origin of the enhanced slope.

scholarly journals ACE-FTS measurements of trace species in the characterization of biomass burning plumes

2011 ◽  
Vol 11 (23) ◽  
pp. 12169-12179 ◽  
Author(s):  
K. A. Tereszchuk ◽  
G. González Abad ◽  
C. Clerbaux ◽  
D. Hurtmans ◽  
P.-F. Coheur ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Biomass Burning ◽  
Atmospheric Chemistry ◽  
Atmospheric Composition ◽  
Fourier Transform Spectrometer ◽  
Free Troposphere ◽  
Convective Processes ◽  
Trace Species ◽  
Chemistry Experiment

Abstract. To further our understanding of the effects of biomass burning emissions on atmospheric composition, we report measurements of trace species in biomass burning plumes made by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) instrument on the SCISAT-1 satellite. An extensive set of 15 molecules, C2H2, C2H6, CH3OH, CH4, CO, H2CO, HCN, HCOOH, HNO3, NO, NO2, N2O5, O3, OCS and SF6 are used in our analysis. Even though most biomass burning smoke is typically confined to the boundary layer, some of these emissions are injected directly into the free troposphere via fire-related convective processes and transported away from the emission source. Further knowledge of the aging of biomass burning emissions in the free troposphere is needed. Tracer-tracer correlations are made between known pyrogenic species in these plumes in an effort to characterize them and follow their chemical evolution. Criteria such as age and type of biomass material burned are considered.

scholarly journals Low albedos of hot to ultra-hot Jupiters in the optical to near-infrared transition regime

2019 ◽  
Vol 624 ◽  
pp. A62 ◽  
Author(s):  
M. Mallonn ◽  
J. Köhler ◽  
X. Alexoudi ◽  
C. von Essen ◽  
T. Granzer ◽  
...  
Keyword(s):  
Near Infrared ◽  
State Of The Art ◽  
Light Curves ◽  
Transition Regime ◽  
Light Component ◽  
Hot Jupiters ◽  
Upper Limit ◽  
Reflected Light ◽  
Geometric Albedo ◽  
Hot Jupiter

The depth of a secondary eclipse contains information of both the thermally emitted light component of a hot Jupiter and the reflected light component. If the day side atmosphere of the planet is assumed to be isothermal, it is possible to disentangle both. In this work, we analyzed 11 eclipse light curves of the hot Jupiter HAT-P-32 b obtained at 0.89 μm in the z′ band. We obtained a null detection for the eclipse depth with state-of-the-art precision, −0.01 ± 0.10 ppt. We confirm previous studies showing that a non-inverted atmosphere model is in disagreement to the measured emission spectrum of HAT-P-32 b. We derive an upper limit on the reflected light component, and thus, on the planetary geometric albedo Ag. The 97.5% confidence upper limit is Ag < 0.2. This is the first albedo constraint for HAT-P-32 b, and the first z′ band albedo value for any exoplanet. This finding disfavors the influence of large-sized silicate condensates on the planetary day side. We inferred z′ band geometric albedo limits from published eclipse measurements also for the ultra-hot Jupiters WASP-12 b, WASP-19 b, WASP-103 b, and WASP-121 b, applying the same method. These values consistently point to a low reflectivity in the optical to near-infrared transition regime for hot to ultra-hot Jupiters.

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