From the Report for Academic Year 1989-1990
of the Institute for Advanced Study
PIET HUT spent the academic year 1989-90 on sabbatical in Japan and Holland, visiting the astronomy department at the universities of Tokyo and Utrecht. In Tokyo he was involved in large-scale simulations of the evolution of dense star systems in collaboration with Japanese colleagues, using a supercomputer at the Institute for Supercomputing Research. One of the most important results of these simulations was a statistical description of the migration processes of primordial double stars through a star cluster. In Utrecht he taught a course on the evolution of globular star clusters. His research in Holland focused on observational aspects of star cluster evolution, especially those connected to low-mass X-ray binaries and millisecond pulsars.