Effects of the Planar Galactic Tides and Stellar Mass on Comet Cloud
  Dynamics
  We report the first results of a research program to explore the sensitivity
of the orbits of Oort cloud comets to changes in the strength of the Galactic
tides in the plane of the disk and also to changes in the mass of the host
star. We performed 2D simulations that confirm that the effects of the tides on
comet orbits are sensitive to a star's distance from the Galactic center. A
comet cloud closer to the Galactic center than the Sun will have comet
perihelia reduced to the region of the inner planets more effectively by the
planar tides alone. Similar results are found for a star of smaller mass. We
also show how this phenomenon of comet injection persists for a set of
alternative Galactic potential models. These preliminary results suggest a
fruitful line of research, one that aims to generalize the study of comet cloud
dynamics to systems different from the Solar System. In particular, it will
allow us to study the roles played by comet clouds in defining the boundaries
of the Galactic Habitable Zone.
