Figure 12-6 SN 1987A and Its “Three-Ring Circus” (a) This true-color view from the Hubble Space Telescope shows three bright rings around SN 1987A. (b) This drawing shows the probable origin of the rings. A wind from the progenitor star formed an hourglass-shaped shell surrounding the star. (Compare with Figure 11-29.) Ultraviolet light from the supernova explosion ionized ring-shaped regions in the shell, causing them to glow.