Planetary Systems around White Dwarfs

Planetary systems are prevalent around main sequence stars. However, little is known about their fate once the star evolves off the main sequence. In this talk, I will present different evidence that planetary systems are present and active around white dwarfs. Similar to main-sequence stars, white dwarfs have debris disks made from dust and gas. These debris disk hosts often have a heavily polluted atmosphere – spectroscopic observations can uniquely reveal chemical compositions of extrasolar planetesimals, which are hard to measure with other techniques. Recent discoveries of transiting planetesimals and planets have opened up many new opportunities to characterize these extreme planetary systems.