¹Kate Y. L. Su, ^2,3Attila Moór, ^2,3Ágnes Kóspál, ^4,5George H. Rieke, ⁴Antranik A. Sefilian, ⁵Renu Malhotra, ^5,6Ilaria Pascucci, ⁶Alan P. Jackson, ^2,3,7Péter Ábrahám, ^1,8Nicholas P. Ballering
The Astrophysical Journal, 1010, 1
Open Access Link to Article [DOI: 10.3847/1538-4357/ae88fe]
¹Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
²Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences, MTA Centre of Excellence, Konkoly-Thege Miklós út 15-17, 1121 Budapest, Hungary
³CSFK, MTA Centre of Excellence, Budapest, Konkoly Thege Miklós út 15-17., H-1121, Hungary
⁴Department of Astronomy and Steward Observatory, University of Arizona, Tucson, AZ 85721, USA
⁵Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721, USA
⁶Department of Physics, Astronomy, and Geosciences, Towson University, 8000 York Road, Towson, MD, USA
⁷Department of Astrophysics, University of Vienna, Türkenschanzstr. 17, A-1180 Vienna, Austria
⁸Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706, USA

Debris disks are dusty structures around mature stars, primarily identified by infrared excesses in the stellar spectra. A subset, known as extreme debris disks (EDDs), exhibits stochastic infrared variability, believed to result from large-scale violent collisions that contribute to the formation or destruction of rocky planetary bodies. We analyze JWST and Spitzer mid-infrared spectra for 21 EDDs to investigate the connection between impact-produced dust mineralogy and the age and dynamical state of these systems during various stages of planet formation and evolution. Our findings indicate that EDDs contain significantly more optically thin, small dust grains compared to those typically seen in protoplanetary and debris disks. Predominantly submicron in size, these grains are thermally altered, as shown by their high levels of silica and crystalline silicate composition. Along with stochastic infrared variability, these features define EDDs as a subclass of debris systems where dust is generated from large collisions between Moon- and Mars-sized bodies. Our results not only provide a diagnostic information about the physical conditions of violent events during terrestrial planet formation, aiding in differentiating the complex outcomes of these impacts, but also offer a potential marker for identifying planetary systems experiencing dynamical instability.