New phenomena in triaxial stellar systems

For a number of years the Geneva Observatory stellar dynamics group has undertaken numerical investigations of stellar orbital behaviour in conservative dynamical systems with three degrees of freedom. Compared to results for 3-D axisymmetrical models (2 degrees of freedom), this work displayed the advent of several new phenomena which may appear in rotating or non-rotating stellar systems with three unequal axes (ellipticals, bulges, bars). In this paper, some remarks are made on tilted orbits, instability types and the numbers of isolated integrals of motion. (Auth.)