| Description |
Debris disks are the signposts of planetary systems: collisions among asteroidal and cometary parent bodies maintain the observed dust population against losses to radiation pressure and P-R drag. While hundreds of debris disks are known fromfar-IR excecss emission around main sequence stars, the best-understood systems are the ~20 that are spatially resolved.Disk images establish the size scale of an exoplanetary system.They can reveal central holes, rings, gaps, warps, and asymmetriesin the dust distribution which indicate the presence of planetaryperturbers. Disk images at different wavelengths are sensitive to dust grains of different sizes, and thus provide a way to trace dusttransport and segregation processes. In spring 2011 we discovered large new debris disk in HSTcoronagraphic images. The new system is an eccentric ring with a sharp inner edge and cleared central zone, and thus is remarkablysimilar to the classic Fomalhaut debris ring. Spitzer only detectedthe system at a single wavelength. We propose PACS and SPIRE imaging photometry to fully establish the spatial and spectralproperties of this new debris system, and of three otherHST-detected debris disks that lack Herschel measurements.Simultaneous modeling of the far-IR images, SEDs, and HST imagesof these disk will provide important constraints on the physicalproperties and dynamical state of their constituent dust.Our small program will complete Herschels legacy dataset forthe key subsample of bright disks that are detected in scacttered light, |
