相关论文: Temporal variations in the evaporating atmosphere …
Water is predicted to be among, if not the most abundant molecular species after hydrogen in the atmospheres of close-in extrasolar giant planets (hot-Jupiters) Several attempts have been made to detect water on an exoplanet, but have…
The nearby transiting planet HD 189733b was observed during three transits with the ACS camera of the Hubble Space Telescope in spectroscopic mode. The resulting time series of 675 spectra covers the 550-1050 nm range, with a resolution…
We present a new Keck/NIRSPEC observation of metastable helium absorption from the upper atmosphere of HD 189733b, a hot Jupiter orbiting a nearby moderately active star. We measure an average helium transit depth of $0.420 \pm 0.013$%…
Two decades after the discovery of 51 Peg b, the formation processes and atmospheres of short-period gas giants remain poorly understood. Observations of eccentric systems provide key insights on those topics as they can illuminate how a…
Atmospheric escape's potential to shape the exoplanet population motivates detailed observations of systems actively undergoing escape. AU Mic is a young and active M dwarf hosting two close-in transiting sub- to Neptune-sized planets.…
High-accuracy multicolor light curves of the binary system HD 189733, which contains an exoplanet, are analyzed. We have determined the radii of the star and the planet in the binary system, as well as the orbital inclination. The…
We present new X-ray observations obtained with Chandra ACIS-S of the HD 189733 system, consisting of a K-type star orbited by a transiting Hot Jupiter and an M-type stellar companion. We report a detection of the planetary transit in soft…
Lyman-$\alpha$ transits have been detected from several nearby exoplanets and are one of our best insights into the atmospheric escape process. However, due to ISM absorption, we typically only observe the transit signature in the…
Since the mass loss rates are the function of the mean density of the planet and the stellar irradiation, we calculated about 450 models covering planets with different densities and stellar irradiation. Our results show that the mass loss…
The atmosphere of the exoplanet HD 209458b is undergoing sustained mass loss, believed to be caused by X-ray and extreme-ultraviolet (XUV) irradiation from its star. The majority of this flux is not directly observable due to interstellar…
The transit spectrum of the exoplanet HD 189733b has recently been obtained between 0.55 and 1.05 microns. Here we present an analysis of this spectrum. We develop first-order equations to interpret absorption spectra. In the case of HD…
We present global, three-dimensional numerical simulations of the atmospheric circulation on HD 209458b and HD 189733b and calculate the infrared spectra and light curves predicted by these simulations, which we compare with available…
[Abridged] After many attempts over more than a decade, high-resolution spectroscopy has recently delivered its first detections of molecular absorption in exoplanet atmospheres, both in transmission and thermal emission spectra. Targeting…
Observations of the highly-eccentric (e~0.9) hot-Jupiter HD 80606b with Spitzer have provided some of best probes of the physics at work in exoplanet atmospheres. By observing HD 80606b during its periapse passage, atmospheric radiative,…
Helium is the second-most abundant element in the Universe after hydrogen and is one of the main constituents of gas-giant planets in our Solar System. Early theoretical models predicted helium to be among the most readily detectable…
We report on the measurement of the 7.5-14.7 micron spectrum for the transiting extrasolar giant planet HD 189733b using the Infrared Spectrograph on the Spitzer Space Telescope. Though the observations comprise only 12 hours of telescope…
Transmission spectroscopy allows us to detect molecules in planetary atmospheres, but is subject to contamination from inhomogeneities on the stellar surface. Quantifying the extent of this contamination is essential for accurate…
Hydrodynamic escape can strip the envelopes of close-in exoplanets, but most observations of atmospheric mass loss to date have been confined to planets orbiting K and M dwarfs. A growing body of detections of atmospheric escape from…
We find that a theoretical fit to all the HD 209458b data at secondary eclipse requires that the dayside atmosphere of HD 209458b have a thermal inversion and a stratosphere. This inversion is caused by the capture of optical stellar flux…
Lyman-$\alpha$ transits provide an opportunity to test models of atmospheric escape directly. However, translating observations into constraints on the properties of the escaping atmosphere is challenging. The major reason for this is that…