Errors in numerical simulations of gravitating systems can be magnified
exponentially over short periods of time. Numerical shadowing provides a way of
demonstrating that the dynamics represented by numerical simulations are
representative of true dynamics. Using the Sitnikov Problem as an example, it
is demonstrated that unstable orbits of the 3-body problem can be shadowed for
long periods of time. In addition, it is shown that the stretching of phase
space near escape and capture regions is a cause for the failure of the
shadowing refinement procedure.Comment: 9 pages, 13 figures, accepted in MNRA