debrisdisk

Debris disk, sometimes referred to informally as debrisdisk, is a circumstellar disk of dust and rocky debris that orbits a star, typically around main-sequence stars. Debris disks are composed of planetesimals—remnants of planet formation—that collide and grind down to produce fine dust. They differ from protoplanetary disks in having relatively low gas content and lower overall mass, and they can persist around stars for hundreds of millions to billions of years.

The dust in a debris disk is replenished by collisional cascades among planetesimals. Individual grains are small and short-lived because stellar radiation pressure and collisions remove or eject them, so continuous replenishment is required. The disk’s structure—rings, gaps, and clumps—often reflects gravitational sculpting by planets. Observations across the electromagnetic spectrum reveal temperature distributions and geometry, ranging from warm inner belts to cold outer disks.

Detection and study rely on excess infrared emission relative to the star’s photosphere, as well as direct imaging and submillimeter interferometry. Space-based infrared missions such as Spitzer and Herschel, along with ground-based facilities like ALMA, have cataloged hundreds of debris disks and resolved several into distinct rings. Notable systems include Beta Pictoris, Vega, Fomalhaut, and AU Microscopii, each offering insights into planetary system architectures and belt evolution. Debris disks thus inform models of planet formation and the dynamical history of planetary systems.