Dynamical effects of the radial galactic tide on an Oort cloud of comets   for stars with different masses and varying distances from the galactic   center
  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. 
Marco Masi