Planetary Systems around White Dwarfs
Siyi Xu
Gemini Observatory

Recent studies have shown that extrasolar planetary systems are prevalent around main-sequence stars in the Milky Way. However, little is known about their fate towards the end of the stellar evolution. In this talk, I will show various evidences that planetary systems could be prevalent around white dwarfs. I will also talk about the recent discovery of an actively disintegrating asteroid around the white dwarf WD 1145+017. This white dwarf is heavily polluted, displays excess infrared radiation from a dust disk, and also has circumstellar gas. I will present our recent photometric and spectroscopic studies of WD 1145+017 and how it fits into our overall understanding of the fate of planetary systems.