相关论文: Spatially resolved spectroscopy across stellar sur…
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…
High-precision stellar analyses require hydrodynamic 3D modeling. Such models predict changes across stellar disks of spectral line shapes, asymmetries, and wavelength shifts. For testing models in stars other than the Sun, spatially…
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…
CONTEXT: High-precision stellar analyses require hydrodynamic modeling to interpret chemical abundances or oscillation modes. Exoplanet atmosphere studies require stellar background spectra to be known along the transit path while detection…
Differential spectroscopy during exoplanet transits permits to reconstruct spectra of small stellar surface portions that successively become hidden behind the planet. The center-to-limb behavior of stellar line shapes, asymmetries and…
Testing 3D hydrodynamic models of stellar atmospheres is feasible by retrieving spectral line shapes across stellar disks, using differential spectroscopy during exoplanet transits. From synthetic data at hyper-high spectral resolution,…
The Wide Field Camera 3 (WFC3) on Hubble Space Telescope (HST) is currently one of the most widely used instruments for observing exoplanetary atmospheres, especially with the use of the spatial scanning technique. An increasing number of…
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,…
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…
All far ultraviolet observations of HD209458 tend to support a scenario in which the inflated hydrogen atmosphere of its planetary companion strongly absorbs the stellar \lya flux during transit. However, it was not clear how the transit…
Four transits of the planet orbiting the star HD209458 were observed with the STIS spectrograph on board HST. The wavelength domain (1180-1710A) includes HI as well as CI, CII, CIV, NV, OI, SI, SiII, SiIII and SiIV lines. During the…
Atomic hydrogen escaping from the planet HD209458b provides the largest observational signature ever detected for an extrasolar planet atmosphere. However, the Space Telescope Imaging Spectrograph (STIS) used in previous observational…
We have observed 4 transits of the planet of HD 209458 using the STIS spectrograph on HST. Summing the recorded counts over wavelength between 582 nm and 638 nm yields a photometric time series with 80 s time sampling and relative precision…
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…
Current observations of the atmospheres of close-in exoplanets are predominantly obtained with two techniques: low-resolution spectroscopy with space telescopes and high-resolution spectroscopy from the ground. Although the observables…
The growth of spectroscopic observations of exoplanetary systems allows the possibility of testing theoretical models and studying the interaction that exoplanetary atmospheres have with the wind and the energetic photons from the star. In…
What makes the study of exoplanetary atmospheres so hard is the extraction of its tiny signal from observations, usually dominated by telluric absorption, stellar spectrum and instrumental noise. The High Resolution Spectroscopy has emerged…
We characterise the planet-occulted line distortions (POLDs) in absorption spectra of transiting planets, that arise from proxies used for the occulted stellar lines and investigate the impact of stellar rotation, centre-to-limb variations,…
Using STIS - HST observations, we have detected an extended upper atmosphere in the extrasolar planet HD209458b . The spectra show an absorption of (15+/-4)% of the stellar Ly-alpha emission line during the planetary transit in front of the…
Evolved stars are among the largest and brightest stars and they are ideal targets for the new generation of sensitive, high resolution instrumentation that provides spectrophotometric, interferometric, astrometric, and imaging observables.…