Related papers: Star-planet interaction through spectral lines
We present a 3D study of the formation of refractory-rich exospheres around the rocky planets HD219134b and c. These exospheres are formed by surface particles that have been sputtered by the wind of the host star. The stellar wind…
Hot giant exoplanets are very exotic objects with no equivalent in the Solar System that allow us to study the behavior of atmospheres under extreme conditions. Their thermal and chemical day--night dichotomies associated with extreme wind…
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…
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…
Absorption in the stellar Lyman-$\alpha$ (Ly-$\alpha$) line observed during the transit of the extrasolar planet HD 209458b reveals high velocity atomic hydrogen at great distances from the planet. This has been interpreted as hydrogen…
Because of the unquestionable presence of magnetic fields in stars, their role in the structure of stellar atmospheres has for a long time been a subject of speculation. In our contribution to this discussion we present spectropolarimetric…
Magnetic star-planet interactions (SPI) provide a detection method and insight into exoplanet magnetic fields and, in turn, exoplanet interiors and atmospheric environments. These signatures can be sporadic and difficult to confirm for…
We present the results of a comprehensive numerical simulation of the environment around three exoplanet-host stars (HD 1237, HD 22049, and HD 147513). Our simulations consider one of the latest models currently used for space weather…
We discuss the interpretation of distortions to stellar spectral lines with particular attention to line bisectors in the presence of an orbiting planetary companion. We present a simple model whereby light reflected by the companion can…
We present the first three-dimensional circulation models for extrasolar gas giant atmospheres with geometrically and energetically consistent treatments of magnetic drag and ohmic dissipation. Atmospheric resistivities are continuously…
Spectroscopic studies of massive and luminous O-type stellar atmospheres and winds have primarily been done by using 1D, spherically symmetric and stationary models. Both observations and modern theoretical models show that such stars have…
We present an analytic model for the interaction between planetary atmospheres and stellar winds from main sequence M stars, with the purpose of obtaining a quick test-model that estimates the timescale for total atmospheric mass loss due…
The hot Jupiter WASP-43b has now joined the ranks of transiting hot Jupiters HD 189733b and HD 209458b as an exoplanet with a large array of observational constraints on its atmospheric properties. Because WASP-43b receives a similar…
Magnetic (or tidal) interactions between "hot Jupiters" and their host stars can potentially enhance chromospheric and coronal activity. An ideal testbed for investigating this effect is provided by the extreme WASP-18 system, which…
Stellar magnetic activity is an important factor in the formation and evolution of exoplanets. Magnetic phenomena like stellar flares, coronal mass ejections, and high-energy emission affect the exoplanetary atmosphere and its mass loss…
Using the new Cosmic Origins Spectrograph (COS) on the {\it Hubble Space Telescope (HST)}, we obtained moderate-resolution, high signal/noise ultraviolet spectra of HD 209458 and its exoplanet HD 209458b during transit, both orbital…
A small percentage of normal stars harbor giant planets that orbit within a few tenths of an astronomical unit. At such distances the potential exists for significant tidal and magnetic field interaction resulting in energy dissipation that…
Context. Collecting a large variety of exoplanetary atmosphere measurements is crucial to improve our understanding of exoplanets. In this context, it is likely that the field would benefit from broad species surveys, particularly using…
Broad-band exoplanet transit photometry can characterize the planetary atmosphere when observed at multiple selected filters. This observing technique can reveal gradients in the spectra of extrasolar planets, for example the slope of…
Hot gas giant exoplanets can lose part of their atmosphere due to strong stellar irradiation, affecting their physical and chemical evolution. Studies of atmospheric escape from exoplanets have mostly relied on space-based observations of…