It isn't hard -- it occurred at the center of the expanding bullseye pattern.
Although this stellar detonation was first seen almost two decades ago, light from it continues to bounce off clumps of interstellar dust and be reflected to us today.
The first image is an image of the SN 1987A region, while the next four images were created by subtracting consecutive images, taken a year apart, and leaving only the difference between the images.
Light echoes can be seen moving out from the position of the supernova.
Study of these light echoes has enabled more accurate determinations of the location and date of these two supernova explosions that were first visible hundreds of years ago.
