相关论文: A Detection Of H-alpha In An Exoplanetary Exospher…
Atmospheric escape has been detected from the exoplanet HD 209458b through transit observations of the hydrogen Lyman-alpha line. Here we present spectrally resolved Lyman-alpha transit observations of the exoplanet HD 189733b at two…
HD 189733 b is one of the most well-studied exoplanets due to its large transit depth and host star brightness. The focus on this object has produced a number of high-cadence transit observations using high-resolution optical spectrographs.…
There is evidence that the transiting planet HD 209458b has a large exosphere of neutral hydrogen, based on a 15% decrement in Lyman-alpha flux that was observed by Vidal-Madjar et al. during transits. Here we report upper limits on H-alpha…
Absorption of stellar H\alpha\ by the upper atmosphere of the planet HD189733b has recently been detected by Jensen et al. Motivated by this observation, we have developed a model for atomic hydrogen in the n=2 state and compared the…
Detecting heavy atoms in the inflated atmospheres of giant exoplanets that orbit close to their parent stars is a key factor for understanding their bulk composition, and the processes that drive their expansion and interaction with the…
Observations of transits of the hot giant exoplanet HD 189733b in the unresolved HI Lyman-alpha line show signs of hydrogen escaping the upper atmosphere of the planet. New resolved Lyman-alpha observations obtained with the STIS…
High-resolution spectroscopy (R $\ge$ 20,000) at near-infrared wavelengths can be used to investigate the composition, structure, and circulation patterns of exoplanet atmospheres. However, up to now it has been the exclusive dominion of…
Thousands of exoplanets have been detected, but only one exoplanetary transit was potentially observed in X-rays from HD189733A. What makes the detection of exoplanets so difficult in this band? To answer this question, we run Monte-Carlo…
We present direct radii measurements of the well-known transiting exoplanet host stars HD 189733 and HD 209458 using the CHARA Array interferometer. We find the limb-darkened angular diameters to be theta_LD = 0.3848 +/- 0.0055 and 0.2254…
Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H2O), methane (CH4), carbon dioxide (CO2), and carbon monoxide (CO) have been detected in two hot Jupiters. These…
Broadband flux measurements centred around [3.6 $\mu$m] and [4.5 $\mu$m] obtained with Spitzer during the occultation of seven extrasolar planets by their host stars have been combined with parallax measurements to compute the absolute…
One of the most well-studied exoplanets to date, HD 189733 b, stands out as an archetypal hot Jupiter with many observations and theoretical models aimed at characterizing its atmosphere, interior, host star, and environment. We report here…
Transmission spectroscopy at UV wavelengths is a rich and largely unexplored source of information about the upper atmospheres of extrasolar planets. So far, UV transit observations have led to the detection of atomic hydrogen, oxygen and…
This paper presents a detailed hydrostatic model of the upper atmosphere of HD 189733b, with the goal of constraining its temperature, particle densities, and radiation field over the pressure range $10^{-4}-10\, \mu \rm bar$, where the…
[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…
Hydrogen-dominated atmospheres of hot exoplanets expand and escape due to the intense heating by the X-ray and extreme ultraviolet (XUV) irradiation of their host stars. Excess absorption of neutral hydrogen has been observed in the…
Spectroscopic observations of exoplanets are crucial to infer the composition and properties of their atmospheres. HD 189733b is one of the most extensively studied exoplanets and is a corner stone for hot Jupiter models. In this paper, we…
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…
Changes in levels of stellar activity can mimic absorption signatures in transmission spectra from circumplanetary material. The frequency and magnitude of these changes is thus important to understand in order to attribute any particular…
We present new multi-broadband transit photometry of HD 189733b obtained at the Wyoming Infrared Observatory. Using an ensemble of five-band Sloan filter observations across multiple transits we have created an "ultra-low" resolution…