  In Galactic open clusters, there is an apparent paucity of white dwarfs
compared to the number expected assuming a reasonable initial mass function and
that main-sequence stars with initial mass <= 8 M_sun become white dwarfs. We
suggest that this lack of white dwarfs is due at least in part to dynamical
processes. Non-spherically symmetric mass loss during the post-main-sequence
evolution would lead to a few km/s isotropic recoil speed for the white dwarf
remnant. This recoil speed can cause a substantial fraction of the white dwarfs
formed in a cluster to leave the system. We investigate this dynamical process
by carrying out high-precision N-body simulations of intermediate-mass open
clusters, where we apply an isotropic recoil speed to the white dwarf remnants.
Our models suggest that almost all white dwarfs would be lost from the cluster
if the average recoil speed exceeds twice the velocity dispersion of the
cluster.
