The presence of planets in binary systems poses interesting problems for planet formation theories , both in cases where planets must have formed in very compact discs around the individual stars and where they are located near the edge of the stable circumbinary region , where in situ formation is challenging .
Dust dynamics is expected to play an important role in such systems , since dust trapping at the inner edge of circumbinary discs could aid in situ formation , but would simultaneously starve the circumstellar discs of the solid material needed to form planets .
Here we investigate the dynamics of dust in binary systems using Smooth Particle Hydrodynamics .
We find that all our simulations tend towards dust trapping in the circumbinary disc , but the timescale on which trapping begins depends on binary mass ratio ( q ) and eccentricity as well as the angular momentum of the infalling material .
For q \gtrsim 0.1 , we find that dust can initially accrete onto the circumstellar discs , but as the circumbinary cavity grows in radius , dust eventually becomes trapped in the circumbinary disc .
For q = 0.01 , we find that increasing the binary eccentricity increases the time required for dust trapping to begin .
However , even this longer timescale is likely to be shorter than the planet formation timescale in the inner disc and is insufficient to explain the observed pre-transitional discs .
This indicates that increase in companion eccentricity alone is not enough to allow significant transfer of solids from the outer to the inner disc .