THE ACTION OF THE GALACTIC DISK ON THE OORT CLOUD COMETS - QUALITATIVE STUDY

Averaged equations of motion for the action of the Galactic disk on th e comets from the Oort cloud are studied from the qualitative point of view. The motion is described on a sphere which reflects the actual t opology of the problem. The presence and location of the equilibria is established for all cases including the class of polar orbits. A geom etrical construction is proposed to analyze directly the evolution of the Laplace vector. Specifying the qualitative properties of different classes of cometary orbits may help to identify the effect of Galacti c disk tides in the observed population of comets.