LAGRANGE , Anne-Marie

Context: A new generation of instruments (e.g., JWST, ELTs, PLATO, Ariel) is providing atmospheric spectra and mass/radius measurements for large exoplanet populations, challenging planetary models used to interpret these findings. Aims: We develop a new model, the Heat Atmosphere Density Evolution Solver (HADES), by coupling an atmosphere and...

Context. Reference-star differential imaging (RDI) is a promising technique in high-contrast imaging that is thought to be more sensitive to exoplanets and disks than angular differential imaging (ADI) at short angular separations (i.e., <0.3'). However, it is unknown whether the performance of RDI on ground-based instruments can be improved by...

The β Pictoris system is the closest known stellar system with directly detected gas giant planets, an edge-on circumstellar disc, and evidence of falling sublimating bodies and transiting exocomets. The inner planet, β Pictoris c, has also been indirectly detected with radial velocity (RV) measurements. The star is a known δ Scuti pulsator,...

Dome C, Antarctica is unique in particular for long-duration astronomical observations due to the excellent weather conditions and nearly uninterrupted nights during the Southern winter period. The 40 cm telescope ASTEP has been operating successfully at the Concordia base, at Dome C, since 2010. We describe the new ASTEP+, a major upgrade of...