Pandemonium in the Planetary Graveyard

Defying the notion of the silent graveyard, planetary systems refuse to die quietly. Instead, a significant fraction show one or more signs of dynamical reanimation, with strong indications of general mayhem during the last stages of stellar evolution. I will give a brief tour of these evolved and active planetary systems, which provide major insights into rocky planetary bodies in particular. These descendants of intermediate-mass stars reveal characteristics of their former planetary systems in ways unattainable by conventional methods using main-sequence stars. In particular, the metal pollution observed in white dwarf stars reveals the bulk chemistry of entire planetesimals or planetary fragments, including compelling evidence for Earth-like chemistry, planetary differentiation, and believe it or not -- water. This talk will cover some of the highlights of the active planetary graveyard, including variability and transient behavior