Host: The Japanese Society for Planetary Sciences: Local Organizing Committee for 2006 Fall Meeting
We studied dynamical evolution of the Hot Jupiters orbiting around young host stars with other planets. In the stage of planet formation, the host stars are in pre-main stage and are surrounded by the protoplanetary disks. As the host stars evolve to the main sequence, the stellar radii and the speed of rotation change and the gas disks are depleted. They cause evolution of the orbits of Hot Jupiters. When the Hot Jupiters have large eccentricities, the tidal dissipation of energy during the circularization would induce their interior heating, inflation, Roche lobe overflow, and mass losses. We studied the necessary conditions for the survival of hot Jupiters. We found that the Hot Jupiters in the multiple planetary system orbiting around young stellar objects whose spin periods are longer than a few days may be highly vulnerable to the dissipation of the disk and evolution of the stars.
In the multiple planetary system, orbital instability of planets followed by the tidal circularization is a candidate for the formation mechanism of the Hot Jupiters. We also studied the efficiency of this process. We found the Hot Jupiters can be formed due to the Kozai mechanism.
