Abstract

I will review the patterns of dynamical activity in debris disks as they are revealed by observations with the Spitzer Telescope. The Spitzer data show an overall decline in such activity among all stellar types, but recent detailed analyses reveal significant differences with stellar type. They also suggest that the disks around earlier-type host stars may have a general pattern of relatively complex structure, whereas those around solar-type stars may have simpler structures. On top of these overall patterns, there are a number of classes of rare but extreme systems: 1.) an absence of disks around young stars with very high stellar winds; 2.) huge excesses around stars in the 30 120 Myr age range; and 3.) large outflows in A stars. Each of these classes represents interesting phases in the overall evolution of the planetary systems generating the disks.