  We show that the effects of radial galactic tides alone can change the
dynamics of an Oort cloud of comets around a star in a highly sensitive manner.
The Oort cloud dynamics depends primarily from the star's position in the
Galaxy and its mass. The dynamical variation is characterized by a dramatic
change of comet perihelia, many of which are shifted towards the inner
planetary system if the star's position goes towards the galactic center or if
its mass is set to be smaller. These preliminary result suggested us a possible
future line of research which aims to a better dynamical generalization of
comet orbits around extrasolar systems that might be tested through numerical
simulations of an Oort cloud of comets around non solar type stars and in
different galactic or extragalactic environments.
