Title: Planet formation: pebbles versus planetesimals

Speaker: Yann Alibert (U. Bern)

Abstract: We present planet formation model and compare the effect of assuming core formation by pebble or planetesimal accretion. We in particular compute the interaction between the envelope of forming planets, and the solids they accrete, comparing planetesimal and pebble accretion models. We show that for low mass pebbles, once the planetary embryo is larger than a fraction of the Earth mass, the envelope is large enough to destroy and vaporize pebbles completely before they can reach the core. In the case of forming by accretion of planetesimals, the mass needed to destroy incoming solids can be much larger (up to ten Earth masses). We show what are the consequences of this effect on the later growth of planets.