Radio waves revealed what happened before a star exploded

For the first time, astronomers have captured radio signals from a rare exploding star, exposing what happened in the years leading up to its death. The radio waves reveal that the star violently shed huge amounts of material shortly before it exploded, likely due to interaction with a nearby companion star. This discovery gives scientists a new tool to rewind the clock on stellar deaths. It also shows that some supernovae are far more dramatic in their final moments than previously thought.