Rapid disappearance of a warm, dusty circumstellar disk

TL;DR

This paper reports the unprecedented rapid disappearance of a warm, dusty circumstellar disk around a young star, challenging existing models of disk evolution and planet formation.

Contribution

It presents observational evidence of a swift, unexplained decline in circumstellar dust, highlighting a phase of disk evolution not predicted by current theories.

Findings

Infrared flux from ejecta decreased by a factor of 30 in less than two years.

Star's circumstellar environment transitioned from dusty to nearly dust-free.

Current physical models do not explain this rapid disk dispersal.

Abstract

Stars form with gaseous and dusty circumstellar envelopes, which rapidly settle into disks that eventually give rise to planetary systems. Understanding the process by which these disks evolve is paramount in developing an accurate theory of planet formation that can account for the variety of planetary systems discovered so far. The formation of Earth-like planets through collisional accumulation of rocky objects within a disk has mainly been explored in theoretical and computational work in which post-collision ejecta evolution is typically ignored, although recent work has considered the fate of such material. Here we report observations of a young, Sun-like star (TYC 8241 2652 1) where infrared flux from post-collisional ejecta has decreased drastically, by a factor of about 30, over a period of less than two years. The star seems to have gone from hosting substantial quantities of dusty ejecta, in a region analogous to where the rocky planets orbit in the Solar System, to retaining at most a meagre amount of cooler dust. Such a phase of rapid ejecta evolution has not been previously predicted or observed, and no currently available physical model satisfactorily explains the observations.