Description
The radial-velocity technique was the first to reveal an exoplanet and it is the second most successful one. It is particularly sensitive to large mass planets, which trigger more disruptive gravitational interactions in the system. It is also not limited to planets in the line-of-sight (like the transit technique). Therefore, some of the most unexpected dynamical configurations were found with this technique (e.g., planets with high mutual inclinations or planets in compact binaries). By correctly modeling the planet-planet interactions, we can extract the complete dynamical configuration of the orbits (e.g., retrograde planets) and their true masses.
Multiplanetary systems in resonance offer a unique insights into planet formation and evolution. While resonant configurations, particularly among sub-Neptunes, probe dynamical and atmospheric interplay, their origins and survival rates remain debated. Theoretical models suggest primordial misalignment could disrupt resonance during formation; consequently, surviving resonant systems are...
V1298 Tau is a very young (20 ± 10 Myr) multi-planetary system that represents a benchmark laboratory for studying the early stages of planets' formation and evolution. Mainly due to the high levels of stellar magnetic activity, an undisputed description of the system has remained elusive so far, including the measurements of the planetary masses and densities, and the characterisation of its...
WASP-148 is an extrasolar system including two giant planets near the 4:1 mean-motion resonance. The inner one was first identified as a transiting candidate on a 8.8-d period from the SuperWASP photometric survey, then the SOPHIE spectrograph allowed it to be characterized, as well as the outer (P = 34.5 days) planet to be detected. Among other effects, the mutual gravitational interactions...
Super-Earths and sub-Neptunes are the most abundant type of planets in the Galaxy, and yet, they are absent from the Solar System. A possible reason for this absence is the giant planets. Indeed, their gravitational influence could have prevented the inward migration of enough disc material needed to form super-Earths. Dedicated RV surveys investigate this hypothesis, by searching for inner...
While several thousand exoplanets are now confirmed, the number of known transiting warm Jupiters ($10 ~\text{d} < \text{period} < 200 ~ \text{d}$) remains relatively small. These planets are generally believed to have formed outside the snowline and migrated to their current orbits. Because they are sufficiently distant from their host stars, they mitigate proximity effects and so offer...
Most detected transiting planets have orbits of a few tens of days, exposing them to intense stellar irradiation and interactions that significantly alter their properties. In contrast, colder planets with longer orbital periods are less affected, offering crucial insights into their formation and migration histories. In this talk, I report the detection and characterization of two...
The nearest rocky exoplanets are non-transiting, making their atmospheric characterization possible only through a combination of high spatial and spectroscopic separation of planetary and stellar light. Nearby rocky planets, particularly those in the habitable zone of their host stars, are prime targets for future missions such as LIFE and HWO to search for biosignatures. Most nearby stars...
Multiplanet systems in the exoplanet catalogues appear to be less well represented than Kepler transit statistics would suggest. Identification of exoplanet periodicities in radial velocity data via the sequential addition of Keplerian signals may lead to systematically biased multiplanet solutions. A Bayesian approach instead allows us to determine the optimal number of planet candidates by...
