Long-term evolution of Oort Cloud comets: methods and comparisons

Two long-term simulation methods for cometary orbits, a Monte Carlo method and a direct integration method, are compared with each other. The comparis on is done in seven inclination and perihelion distance intervals, and show s differences in dynamical lifetime and capture probabilities for the follo wing main reasons. We use a finite energy step approximation in the Monte C arlo method and the method considers only close approaches with the planets . The differences can be taken into account statistically and it is possibl e to calculate the correction factors for the capture probability and dynam ical Lifetime in the Monte Carlo method. Both corrections depend on the inc lination and on the value of the minimum energy step. The capture probabili ties of the short-period comets originating in the Oort Cloud are calculate d by the corrected Monte Carlo method and compared with published results.