Stability and Chaos in Planetary Systems

摘要

One of the major news stories of the year was the detection of multiple planets around a Sun-like star Upsilon Andromedae). Aside from being a first detection, this discovery was very interesting because the arrangement of the three planets in the Upsilon Andromedae system is drastically different from the arrangement of our own system. The two outer Upsilon Andromedae planets are considerably more massive than Jupiter, and they have orbits that are much more eccentric than those of the major planets in our system. However, the radial velocity observations used to make the discovery can determine only lower limit for the planetary masses. Furthermore, there were several different data sets compiled by competing teams of observers. Two important questions thus remained, both of which were addressed by Ames-based theoretical research: a) What is the true mass of the planets and b) Which set of published orbital parameters best represents the true configuration of the system Work in FY99 focused extensively on these questions, and examined other aspects of the general problem of planetary orbital stability.