Characterizing the End Stage of Exoplanetary Systems

Planetary systems are ubiquitous around young and old stars. In addition to planets orbiting a star, a planetary system also harbors minor bodies like asteroids and comets, signaling their presence as circumstellar dusty and gaseous material. Through various observing techniques (e.g., infrared excesses and metal pollution in white dwarf atmospheres), we now know that dusty material exists around hundreds of white dwarfs, the end stage of the majority of the stars. Standard models suggest that these dusty disks are formed by the tidal disruption of a scattered planet or minor bodies, feeding heavy elements onto white dwarfs that pollute their otherwise pure hydrogen or helium atmospheres. To better understand the formation and evolution of dusty disks around stellar remnants, we propose MIRI/MRS observations for a sample of bright dusty white dwarfs that show distinct 10 micron silicate features revealed from low-resolution Spitzer data. We aim to combine these data with state-of-the-art models to comprehensively probe the dust composition and geometric structures in the disk, and assess its dynamical stage by comparing with theoretical expectations. Detailed dust mineralogy derived from the data will allow for a direct comparison with the metal abundance measured from the atmospheric pollution, and shed light on the size and formation condition of disintegrating bodies.