Hidden Star Finally Revealed after 21 Years

Sep 11, 2014

A supernova detonates once every second somewhere in the universe.  The rare Type IIb supernova (SN 1993J) combines the features of a supernova explosion in a binary system with what’s seen when a single massive star explodes.   "This is like a crime scene, and we finally identified the robber," says Alex Filippenko from the University of California, Berkeley.