Amidst the glitter of billions of stars in the majestic spiral galaxy called the Whirlpool (M51), a massive star abruptly ends its life in a brilliant flash of light. NASA/ESA Hubble Space Telescope snapped images of the exploding star, called supernova (SN) 2005cs, 12 days after its discovery. Astronomers then compared those photos with Hubble images of the same region before the supernova blast to pinpoint the progenitor star (the star that exploded).