CRIDA , Aurélien

Planetary migration seems to be unavoidable during planet formation in protoplanetary disks. Gravitational interactions between the planet embryos and the gas disk make the angular momentum of the embryo decrease, so that it spirals towards the central star. As the migration timescale is shorter than the disk life time, no planet should survive...

Simulations show that the still-mysterious origin of Saturn's vast, icy rings could be explained by the 'peeling' by Saturn's tides of the icy mantle of a large satellite migrating towards the planet

Simulations show that the still-mysterious origin of Saturn's vast, icy rings could be explained by the 'peeling' by Saturn's tides of the icy mantle of a large satellite migrating towards the planet

International audience

International audience

The discovery of multiple transiting planetary systems offers new possibilities for characterising exoplanets and understanding their formation. The Kepler-9 system contains two Saturn-mass planets, Kepler-9b and 9c. Using evolution models of gas giants that reproduce the sizes of known transiting planets and accounting for all sources of...

International audience

Spectacular results from Cassini's Grand Finale have provided constraints on the characteristics and evolutionary processes of Saturn's rings. These results have been interpreted as proof that the rings are much younger than the Solar System, dramatically changing our view of the origin of the whole Saturnian system and attracting the attention...

International audience

Context. Magnetically-driven disk winds would alter the surface density slope of gas in the inner region of a protoplanetary disk (r ≲ 1 au). This in turn affects planet formation. Recently, the effect of disk wind torque has been considered with the suggestion that it would carve out the surface density of the disk from inside and would induce...

International audience

Abstract Free-floating planets (FFPs) can result from dynamical scattering processes happening in the first few million years of a planetary system's life. Several models predict the possibility, for these isolated planetary-mass objects, to retain exomoons after their ejection. The tidal heating mechanism and the presence of an atmosphere with...

Context. The 98° obliquity of Uranus is commonly attributed to giant impacts that occurred at the end of the planetary formation. This picture, however, is not devoid of weaknesses. Aims. On a billion-year timescale, the tidal migration of the satellites of Jupiter and Saturn has been shown to strongly affect their spin-axis dynamics. We aim to...

Context. A fundamental element of galaxy formation is the accretion of mass through mergers of satellites or gas. Recent dynamical analyses based on Gaia data have revealed major accretion events in the history of the Milky Way. Nevertheless, our understanding of the primordial Galaxy is hindered because the bona fide identification of the most...

The origin of Saturn's inner mid-sized moons (Mimas, Enceladus, Tethys, Dione and Rhea) and Saturn's rings is debated. Charnoz et al. [Charnoz, S., Salmon J., Crida A., 2010. Nature 465, 752-754] introduced the idea that the smallest inner moons could form from the spreading of the rings' edge while Salmon et al. [Salmon, J., Charnoz, S.,...

The origin of Saturn's inner mid-sized moons (Mimas, Enceladus, Tethys, Dione and Rhea) and Saturn's rings is debated. Charnoz et al. (2010) introduced the idea that the smallest inner moons could form from the spreading of the rings' edge while Salmon et al. (2010) showed that the rings could have been initially massive, and so was the ring's...

To keep current global warming below 1.5 • C compared with the pre-industrial era, measures must be taken as quickly as possible in all spheres of society. Astronomy must also make its contribution. In this proceeding, and during the workshop to which it refers, different levers of actions are discussed through various examples: individual...