相关论文: Combined analysis of stellar and planetary absorpt…
Transmission spectroscopy has enabled the analysis of exoplanet atmospheres. However, a major challenge is the noise from host stars, caused by stellar activity such as dark spots and bright plages. This noise can mimic or obscure signals…
While transmission spectroscopy has allowed us to detect many atomic and molecular species in exoplanet atmospheres, the improvement in resolution and signal-to-noise ratio enabled us to become sensitive to planet-occulted line distortions…
In-depth studies of exoplanetary atmospheres are starting to become reality. In order to unveil their properties in detail, we need spectra with a higher S/N and also more sophisticated analysis methods. With high-resolution spectrographs,…
Sodium and potassium signatures in transiting exoplanets can be challenging to isolate from the stellar absorption lines. Here, these challenges are discussed in the framework of Solar System observations, and transits of Mercury in…
During primary transits, the spectral signatures of an exoplanet atmosphere can be measured using transmission spectroscopy. The goal of this work is to accurately measure the atomspheric sodium absorption light curve in HD189733b,…
We investigate the effect of planetary rotation on the transit spectrum of an extrasolar giant planet. During ingress and egress, absorption features arising from the planet's atmosphere are Doppler shifted by of order the planet's…
Transmission spectroscopy during planetary transits, which is based on the measurements of the variations of planet-to-star radius ratio as a function of wavelength, is a powerful technique to study the atmospheric properties of transiting…
In recent years it has become common practice to divide observed transit absorption spectra by synthetic absorption spectra computed for the transit of an atmosphere-less planet. This action supposedly corrects the observed absorption…
Transit spectroscopy is one of the most commonly used techniques for exoplanet atmosphere characterisation. This technique has been used to detect ionized and neutral species in exoplanet atmospheres by comparing the observed stellar lines…
Observations of stellar surfaces - except for the Sun - are hampered by their tiny angular extent, while observed spectral lines are smeared by averaging over the stellar surface, and by stellar rotation. Exoplanet transits can be used to…
We present a direct method for isolating the component of the starlight blocked by a planet as it transits its host star, and apply it to spectra of the bright transiting planet HD 189733b. We model the global shape of the stellar…
The recent transit observation of HD 209458 b - an extrasolar planet orbiting a sun-like star - confirmed that it is a gas giant and determined that its orbital inclination is 85 degrees. This inclination makes possible investigations of…
Transmission spectroscopy has greatly advanced the study of exoplanet atmospheres, but stellar surface heterogeneities can contaminate transit spectra. Characterising how stellar spectra vary across the stellar disc is therefore essential…
CONTEXT: High-resolution spectroscopy across spatially resolved stellar surfaces aims at obtaining spectral-line profiles that are free from rotational broadening; the gradual changes of these profiles from disk center toward the stellar…
Although atmospheric transmission spectroscopy of HD209458b with the Hubble Space Telescope has been very successful, attempts to detect its atmospheric absorption features using ground-based telescopes have so far been fruitless. Here we…
Context. The spectra of fast-rotating A-type stars have strongly broadened absorption lines. This effect causes blending of the absorption lines, hindering the measurement of the abundances of the elements that are in the stellar…
We report the first detection of a planetary transit by spectroscopic measurements. We have detected the distortion of the stellar line profiles during a planetary transit. With the ELODIE spectrograph we took a sequence of high precision…
Spectroscopy across spatially resolved stellar surfaces reveals spectral line profiles free from rotational broadening, whose gradual changes from disk center toward the stellar limb reflect an atmospheric fine structure that is possible to…
Spectroscopic transit detection of constituents in winds from "evaporating" planets on close-in transiting orbits could provide desperately needed information on the composition, formation, and orbital evolution of such objects. We obtained…
Future telescopes will characterize rocky exoplanets in reflected light, revealing their albedo, which depends on surface, cloud, and atmospheric properties. Identifying these features is crucial for assessing habitability. We present…