  Chandrasekhar's theory of stellar encounters predicts a dependence of the
Brownian motion of a massive particle on the velocity distribution of the
perturbing stars. One consequence is that the expectation value of the massive
object's kinetic energy can be different from that of the perturbers. This
effect is shown to be modest however, and substantially smaller than claimed in
a recent study based on a more approximate treatment of the encounter
equations.
