'Messy' star that caused partner star to explode identified

Researchers have identified the 'messy' star that made its partner star in a twin-star system explode as a supernova 545 million light-years away. Hydrogen-rich debris was shed by the 'messy' star before the explosion, which revealed that it was either a 'red giant' or a similar star. Supernova material had hit the debris at 10% the speed of light.