Evolution of the spectral energy distribution (SED) of the simulation from Fig. 2. Each curve shows the SED during a given simulation snapshot. The instability occurred at 21 Myr, and the SED evolved dramatically in the immediate aftermath, as icy planetesimals were scattered onto high-eccentricity orbits – thereby producing transient hot dust – and then ejected from the system. The dashed line represents the stellar photosphere. The system is viewed at a distance of 10 pc.