Program: GS-2009A-Q-28

Planet formation is thought to occur within protoplanetary disks. Such disks last <10Myr and so it is often assumed that planet formation is complete by this time. However, observations of debris disks (i.e., dust present after dispersal of the protoplanetary disk) are challenging this view, suggesting that planet formation continues up until several 100Myr. Here we propose to image the 12-100Myr debris disk of HD191089 at 18micron using TReCS. Analysis based on our previous mid-IR programme shows this disk is resolvable, the only remaining debris disk we predict to be resolvable in the mid-IR. We will use the resulting images to assess the state of planet formation within the disk: the radial profile will be compared with that expected from ongoing planet formation models in which dust is the result of recent Pluto formation, and asymmetries seen in the dust structure will be modelled to set constraints on the properties of unseen planets.