SSP seminar

Decoding Debris Disks: Modeling the Dynamical Signatures of Exoplanets

Chris Stark (Maryland)

Monday 16th November 2009, 12:00pm
Pratt conference room, 60 Garden Street

Many main sequence stars exhibit an infrared excess interpreted as thermal emission from a circumstellar dusty debris disk, likely created by collisions or outgassing of planetesimals. Several resolved debris disks show circumstellar ring-like structures likely caused by planetary gravitational perturbations. In our Solar System's tenuous debris disk, the zodiacal cloud, we see the faint signature of the Earth itself, while resolved images of several debris disks much more dense, including Fomalhaut and HR 4796A, exhibit similar structures at much greater circumstellar distances. These structures can act as both a source of noise for future exoplanet-imaging missions and as a signal that we can use to indirectly detect and characterize exoplanets. By modeling observed structures, we can learn about the properties of the perturbing exoplanet, the orbital distribution of the dust-producing planetesimals, and the history of the planetary system. I will present the first model to simultaneously and self-consistently include all of the physical processes necessary to simulate currently detectable debris disk structures and describe the modeling techniques we used. I will show our predictions for the types of structures we may see with future missions that aim to directly image Earth-like exoplanets and present preliminary collisional models of the Fomalhaut debris disk.


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