Colloquium Detail

Formation of Planets Around the Sun and Other Stars.

Date: 11/14/2005

Professor Doug Lin
UC Santa CruzFormation of Planets around the Sun and other stars. The quest to understand the formation of planets and planetary systems has entered an era of renaissance. Driven by observational discoveries in solar system exploration, protostellar disks, and extra solar planets, we have established a rich data bank which contains not only relic clues around mature stars, including the Sun, but also direct image of ongoing processes around young stars. For the first time in this scientific endeavor, we have adequate information to construct quantitative models to account for the ubiquity of planets and diversity of planetary systems. Some of the most intriguing theoretical questions facing us today include: a) how did the planets in the solar system form with their present-day mass, composition, and orbital elements, b) is planet formation a deterministic or chaotic process, and c) what are the observable signatures of planet formation and evolution around nearby young and mature stars? I will present a comprehensive scenario which suggests a) gas giant planets formed through coagulation of planetsimals and gas accretion onto earth-like cores; b) the final assemblage of the terrestrial planets in the solar system occurred through the propagation of Jupiter's secular resonance 4-30 Myrs after the emergence of the gas giant; and c) although they are yet to be discovered, Earth-like planets are expected to be common around nearby stars.