Can a supernova explode twice? It is possible. This occurs when the first explosion acts as the trigger for the second explosion. This is a leading hypothesis for the cause of the supernova remnant SNR 0509-67.5. The larger, more dispersed star among two stars orbiting closely transfers mass to its companion white dwarf (remnant star) due to gravity. The temperature near the surface of the white dwarf increases significantly, causing it to explode first, and the shockwave generated during this event spreads outward and inward, inducing a complete 'Type Ia supernova' at the center. This phenomenon occurs when the white dwarf exceeds its critical mass and explodes.
This image captures the SNR 0509-67.5 system taken with the Very Large Telescope (VLT) in Chile, showing two shells that align with the double explosion hypothesis in terms of radius and composition. SNR 0509-67.5 is also famous for two mysteries: 'why such a bright supernova has not been observed for about 400 years' and 'why a noticeable companion star is not present today.'