Abstract

One of the primary objectives of the upcoming PLATO mission is to identify Earth-like planets transiting Sun-like stars within the Habitable Zone. Achieving the mass precision required for internal structure characterization of these planets requires addressing the challenge posed by stellar activity in RV data. State of the art methods, such as Gaussian Processes (GP), have become the standard procedure to model the stellar activity contribution. However, it is not yet clear how these methods affect the planet’s mass measurement. In the context of PLATO , planet candidates will benefit from contemporary photometry alongside ground-based high-precision RVs, providing a unique opportunity to include photometry in the stellar activity model. In this talk, we revisit the CoRoT-7 system—a young Sun-like star hosting three planets—using HARPS RV and CoRoT photometry. In this study we explore the integration of contemporaneous photometry and RV data to model and mitigate stellar activity signals effectively, and how this impacts the mass measurements of the three planets in this system using multi-dimensional GPs.