Contributions > By speaker > Leleu Adrien

Close-in sub-Neptunes, with radii ranging from 1 to 4 Earth radii and orbital periods of less than 100 days, have been shown to exist around 30 to 50% of sun-like stars, based on early results from the HARPS spectrograph and the Kepler spacecraft. A leading model for the formation of this population is called "breaking the chains" : close-in systems of sub-Neptunes form in resonant chains due to the migration of planets in protoplanetary disks, but most chains become dynamically unstable as the disk dissipates. Resonant configurations are therefore crucial to understanding the formation of about half of planetary systems. We can access details of the architecture of resonant systems by observing the effect of planet-planet gravitational interactions on the timing of planetary transits, known as the transit timing variation (TTV) method. I will discuss the TTV-related challenges and the state-of-the-art methods to alleviate them. I will then describe how these issues potentially impacted major statistical results of the 2010s, notably the apparent paucity of exoplanetary systems within resonances, and the apparent low density of TTV-characterized planets.