Abstract

The vast majority of stars will become white dwarfs at the end of the stellar life cycle. These remnants are precise cosmic clocks owing to their relatively well constrained cooling rates. The Gaia Data Release 2 has discovered 200,000 new white dwarfs and the first direct evidence of the solidification of these stars as they cool. In the next few years we will follow-up these objects spectroscopically within international multi-object spectroscopic surveys (WEAVE, 4MOST). By employing spectroscopically derived atmospheric parameters combined with Gaia parallaxes, white dwarfs can constrain the local stellar formation history in a rather direct way as well as the bulk chemical composition of extrasolar planets. I will discuss the theoretical tools that we are developing to model the atmosphere and evolution of white dwarfs. Most notably, I will show that 3D radiation-hydrodynamics simulations now reach the level of accuracy to be the preferred theoretical tool in spectroscopic and seismic analyses of white dwarfs.