One might expect stars that evolve solely by radiating away their accumulated store of heat, and do so at a nearly constant radius, would reliably shine as they fade. This picture of white dwarfs motivated their use as photometric standard stars during the mid to late 20th century. However, in the late 1960s, Arlo Landolt noticed subtle variations in some of the standards he was calibrating. In the nearly 6 decades since then, the study of pulsating white dwarf stars has become a mature and dynamic subfield of asteroseismology. We’ve thought we decoded these stars on several different occasions, and each time further observations have disrupted our complacency. Even today, we are still exploiting the (mis)behavior to learn about pulsation, turbulence, rotation, convection, and other processes essential to modeling stars of all types. In this talk, I’ll briefly review the oscillating level of understanding of these stars and discuss a few persistent mysteries that we are trying to solve: figuring out why they stop pulsating (we think we know how they start), and explaining their occasional outbursts (flares?) which went unnoticed until space-based photometry revealed this startling misbehavior.
