The image analysis tools of this workbench include the ability to redirect measurements to a be plotted in on a graph. This module provides images of SN1993, a supernova that exploded in the galaxy M81 in 1993. The data were obtained with the Very Long Baseline Array radio telescope. The problem tree asks the student to measure the diameter of the supernova in each image and the results are plotted in the Plotter Tool. The slope of the fitted line in the plotter represents the expansion velocity of the supernova. Students not only about the physics of supernova explosions; they also learn about measurement errors and statistics by deriving quantities from the measurements.