nai

Project Progress

Mayer and Quinn have continued performing simulations of giant planet formation by fragmentation of a gaseous disk, and have published their results in Science. They are extending previous work by considering the effect of different equations of state on the outcome, and by continuing the calculation for longer periods of time.

Lufkin and Quinn have started simulations of giant planet migration in gaseous disks. In a paper submitted to Monthly Notices, they have mapped out the possible migration/formation scenarios as a function of disk mass and planet mass. They demonstrate that the standard picture of a smooth migration inward is probably incorrect, and that the process is a rather chaotic one that involves close encounters and collisions of giant planets.

Barnes and Quinn in collaboration with Lissauer (Ames) continue their simulations of planetesimal accretion in the terrestrial region. They have made progress in speeding up this computationally challenging calculation. The aim is to determine the mass spectrum of planetesimals coming out of the middle stage of planet formation as a function of distance from the Sun.

Barnes and Quinn continue to investigate the stability of extra-solar planetary systems as they are being discovered. They continue to find that most planetary systems, including our own, are on the edge of being unstable. This has implications for the efficiency of planet formation.