Near-parabolic cometary flux in the outer solar system

Abstract

The flux of near-parabolic comets in the outer-planetary region is estimated on the presumption that the major planets and the galactic tide control the dynamics of comets. It is found that the flux of the Oort cloud comet (semi-major axis > 20000 AU) is similar to the case of a strong comet shower derived on the assumption that the galactic tidal force were not operative. On the other hand, the flux of comets with semi-major axes ≤ 20000 AU is found to be an increasing function of q (perihelion distance) until q reaches 20 AU, while for a ∼ 45000 AU it is a rapidly increasing function for q ≤ 12 AU