Planetesimal dynamics in the presence of a giant planet<\/p>\n\n\n\n
speaker: Kangrou Guo<\/p>\n\n\n\n
Abstract:<\/p>\n\n\n\n
Standard models of planet formation explain how planets form in axisymmetric,\u00a0unperturbed disks in single star systems. However, it is possible that giant\u00a0planets could have already formed when other planetary embryos start to grow.\u00a0We investigate the dynamics of planetesimals under the perturbation of a giant\u00a0planet in a gaseous disk. Our aim is to understand the effect of the planet\u2019s\u00a0perturbation on the formation of giant planet cores outside the orbit of the\u00a0planet. We calculate the orbital evolution of planetesimals ranging from\u00a01013<\/sup> to 1020<\/sup> g, with a Jupiter-mass planet located at 5.2 au. We find\u00a0orbital alignment of planetesimals distributed in 9-15 au, except for\u00a0the mean motion resonance (MMR) locations. The degree of alignment increases\u00a0with increasing distance from the planet and decreasing planetesimal mass. Aligned orbits lead to low encounter velocity and thus faster growth. The\u00a0typical velocity dispersion for identical-mass planetesimals is on the order of 10 m\/s\u00a0except for the MMR locations. The\u00a0relative velocity decreases with increasing distance from the planet and\u00a0decreasing mass ratio of planetesimals. When the eccentricity vectors of\u00a0planetesimals reach equilibrium under the gas drag and secular perturbation,\u00a0the relative velocity becomes lower when the masses of two planetesimals are\u00a0both on the larger end of the mass spectrum. Our results show that with a giant\u00a0planet embedded in the disk, the growth of another planetary core outside the\u00a0planet orbit might be accelerated in certain locations. In addition to the results of this paper, I will also show some preliminary results from our follow-up work on the dependence of particle relative velocities on planet parameters (mass and eccentricity).<\/p>\n","protected":false},"excerpt":{"rendered":"