Title: The formation and dynamical evolution of free-floating planets in star clusters
Speaker: Thijs Kouwenhoven (KIAA/PKU)
Time & Place: Thursday, 3:00pm, November 28th, 3rd floor Lecture Hall  

Abstract: The recent discovery of a large population of exoplanets in the Galactic field has provided a wealth of information that helps us understand how planetary systems form and evolve. Exoplanet surveys targeting star clusters, on the other hand, have been less successful: only a hand full of exoplanets have been discovered in these regions. This may be attributed to the frequent encounters experienced by star cluster members, and possibly by a difference in the formation process. The presence of multiple planets in a system (such as our own Solar system) can substantially increase the possibility of planet ejections, which may explain the absence of close-in planets, such as hot Jupiters, that would normally be unaffected by stellar encounters. This talk focuses on the dynamical fate of multi-planet systems in dense stellar systems and on the evolution of the free-floating planet population in star clusters resulting from destabilized planetary systems. Since most of the planet-hosting stars in the Galactic field (and probably even our own solar system) are thought to have formed in clustered stellar environments, this places limits on the properties of the star clusters they may have formed in.  

Biog: Thijs graduated from the University of Amsterdam in 2006, after which he moved to Sheffield as a postdoc before taking up his current position as Bairen Research Professor at KIAA in Beijing. In 2009 he was awarded the prestigious IAU Gruber Foundation Fellowship.