Debris disk

A debris disk is a circumstellar disk of dust and debris in orbit around a star. Sometimes these disks contain prominent rings, as seen in the image of Fomalhaut below. Debris disks have been found around both evolved and young stars, as well as at least one debris disk in orbit around a neutron star.[ They can constitute a phase in the formation of a planetary system following the protoplanetary disk phase.They can also be produced and maintained as the remnants of collisions between planetismals. By 2001, over 900 candidate stars have been found to possess a debris disk. They are usually located by examining the star system in infrared light and looking for an excess of radiation beyond that emitted by the star. This excess is inferred to be radiation from the star that has been absorbed by the disk, then radiated away as infrared energy. Debris disks are often described as massive analogs to the debris in the solar system. Most known debris disks have radii of 10-100 astronomical units; they resemble the Kuiper Belt in the solar system, but with much more dust