  Increasing observations of white dwarf atmospheric pollution and disrupting
planetesimals is driving increased studies into the fate of exo-asteroids
around post-main-sequence stars. Planetesimal populations in the Solar System
which are most likely to survive the violent post-main-sequence evolution, such
as the Kuiper Belt, display a large binary fraction with a propensity for near
equal-mass components and provide a previously unexplored population of
planetesimals which are likely to exist around white dwarfs. Here we simulate
the dynamical evolution of equal-mass binary asteroid systems around white
dwarfs using the N-body integrator REBOUND for 1 Gyr. We confirm that giant
planets are efficient at dissociating and ejecting binary asteroid systems on
eccentric orbits, while Earth-mass planets are better at keeping planetesimals
in their planetary systems. We find binary systems can be dissociated and
ejected from their systems across Myr timescales, producing interstellar
objects. We do not expect a population of free-floating binary asteroid systems
as all ejected planetesimals are gravitationally unbound from each other.
Further, we discuss the influence of asteroid binarity on the white dwarf
pollution process and find there is little to no impact on how close a body can
get to a star. However, the orbital evolution of binary asteroids changes the
distribution of planetesimals available in a white dwarf planetary system to be
further scattered onto white dwarf polluting orbits.
