  The HR 8799 system, with its four giant planets and two debris belts, has an
architecture closely mirroring that of our Solar system where the inner, warm
asteroid belt and outer, cool Edgeworth-Kuiper belt bracket the giant planets.
As such, it is a valuable laboratory for examining exoplanetary dynamics and
debris disk-exoplanet interactions. Whilst the outer debris belt of HR 8799 has
been well resolved by previous observations, the spatial extent of the inner
disk remains unknown. This leaves a significant question mark over both the
location of the planetesimals responsible for producing the belt's visible dust
and the physical properties of those grains. We have performed the most
extensive simulations to date of the inner, unresolved debris belt around HR
8799, using UNSW Australia's Katana supercomputing facility to follow the
dynamical evolution of a model inner disk comprising 300,298 particles for a
period of 60 million years. These simulations have enabled the characterisation
of the extent and structure of the inner disk in detail, and will in future
allow us to provide a first estimate of the small-body impact rate and water
delivery prospects for possible (as-yet undetected) terrestrial planet(s) in
the inner system.
