Institute of Astronomy

Close encounters in the birth environments of planetary systems

SpeakerTalk DateTalk Series
Melvyn Davies28 July 2014Across HR 2014 Talks


The birth environments of planetary systems are crowded places where dynamical encounters between stars are relatively common. We consider the role played by stellar flybys and exchanges into binaries on the formation and evolution of planetary systems. For example, we show how such encounters can destabilise planetary systems, leading to the ejection of some planets whilst leaving others on eccentric orbits. We quantify the frequency of close encounters as a function of initial conditions (i.e. density of star-forming regions, the initial motions of the stars within the region, and the lumpiness of the stellar distribution). We consider the possible role played by free-floating planets within star-forming regions, including encounters between free-floating planets and discs around stars.