Recent work on the dynamics of triaxial stellar systems is reviewed. The motion of boxlike orbits in realistic triaxial potentials is generically stochastic. The degree to which the stochasticity manifests itself in the dynamics depends on the chaotic mixing timescale, which is a small multiple of the crossing time in triaxial models with steep cusps or massive central singularities. Low-lumino...

We investigate how the formation and evolution of extrasolar planetary systems can be affected by stellar encounters that occur in the crowded conditions of a stellar cluster. Using plausible estimates of cluster evolution, we show how planet formation may be supressed in globular clusters while planets wider than > ∼ 0.1 au that do form in such environments can be ejected from their stellar sy...

Piet Hut ∗ a , Michael M. Shara b , Sverre J. Aarseth c , Ralf S. Klessen d , James C. Lombardi Jr. e , Junichiro Makino f , Steve McMillan g , Onno R. Pols h , Peter J. Teuben i , Ronald F. Webbink j Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540, USA Department of Astrophysics, American Museum of Natural History, New York, NY 10024, USA Institute of Astronomy, University of...

Accuracies reached in space astrometry now permit the accurate determination of astrometric radial velocities, without any use of spectroscopy. Knowing this true stellar motion, spectral shifts intrinsic to stellar atmospheres can be identified, for instance gravitational redshifts and those caused by velocity fields on stellar surfaces. The astrometric accuracy is independent of any spectral c...

The simulation of rich star clusters presents challenging problems of several kinds, including the design of suitable hardware and software, and numerous theoretical problems in stellar dynamics and stellar physics. Great progress has been made possible in recent years through the widespread use of GRAPE hardware. Simulations are, however, still too small to be applied to real star clusters wit...