Understanding the evolution of planetary systems: angular momentum exchanges from the core of the host stars to planetary orbits
Mardi 29/09/2020, 10:00-11:00
Bat 713, salle de séminaires Galilée , CEA Saclay, Orme des Merisiers

The simultaneous discoveries of new planetary systems, mostly thanks to the methods of transits and radial velocities, and the detailed characterization of their host star properties (their mass, radius, and age) and dynamics (their rotation and magnetism), thanks to space-based asteroseismology (e.g. Kepler/K2 and TESS) and ground-based spectropolarimetry, allow us to bring our knowledge of the formation, the dynamics, and the evolution of star-planet systems to a new level of understanding. First, it is now well established that the orbital architecture of our Solar system is not typical and that a broad diversity of configurations is possible. These configurations result from intense star-planet interactions. Their strength strongly varies as a function of the mass, the age, the rotation, and the magnetism of the stars and planets. Second, we discover that the interiors of all types of stars (from solar-type to massive stars) are the seat of a strong extraction of angular momentum all along their evolution. At the same time, high-resolution ground-based astrometry and in-situ exploration space missions (JUNO and Cassini) of the gaseous giant planets Jupiter and Saturn and of their systems showed us that the internal structure of these objects is more complex than expected while tidal interactions with their moons are more intense than predicted previously. All these results are challenging state-of-the-art models of angular momentum exchanges within star-planet or planet-moon systems and in stellar interiors. Moreover, they demonstrate the strong dependence of these exchanges on the internal structure, rotation, and magnetism of stars and planets.

In this seminar, we will review the key results we have obtained within the ERC projet SPIRE Stars: dynamical Processes driving tidal Interactions, Rotation and Evolution during these last five years. In particular, we will detail the advances we made in our understanding of angular momentum transport in stars and of tidal interactions and dissipation in stars and in gaseous and telluric planets. We will also show how we have developed a new generation of seismic diagnosis to unravel the internal rotational dynamics of stars and magnetism. Finally, we will discuss the perspectives and open questions that should be addressed in the coming years to accompany the new generation of space missions (e.g. JWST, PLATO, and ARIEL) and ground-based instrumentations that will explore planetary systems.

Organizer: Matteo BUGLI

Contact : Matteo BUGLI



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