Transient dust in warm debris disks

Abstract

Context. Debris disks trace remnant reservoirs of leftover planetesimals in planetary systems. In the past years, a handful of “warm” debris disks have been discovered in which emission in excess starts in the mid-infrared. An interesting subset of these warm debris disks shows emission features in mid-infrared spectra, which points towards the presence of μm-sized dust grains, with temperatures above hundreds K. Given the ages of the host stars, the presence of these small grains is puzzling, and raises questions about their origin and survival in time.