Mean proper-motion vectors overlaid on the QSF finding chart. QSFs are indicated with contours, and those with filled contours have optical counterparts (B.-C. Koo et al. 2018). The filled QSFs without vectors are those for which proper motions could not be determined due to their location in complex environments. The vector scale is provided in the bottom left corner. The background blue contour outlines the main ejecta shell, traced by [Fe II] emission (Figure 1), while the filled blue star symbol marks the explosion center.