Final disk radius (at 50 Myr) vs. minimum disk radius induced by a nearby supernova for those systems in which the disk was most severely truncated by the supernovae. These account for the majority (80%) of the cases, in the other ∼20% the supernova was more effective in truncating the disk than a nearby encounter. The iso-density contours are given for equal decadal percentages. The dotted curve gives the equal radius.