Exploding Stars: Investigating the 1604 and 1987 Supernovas

October 7, 2004  Baltimore, Maryland - Supernovas are stars that explode. Those exploding stars are either small, very dense white dwarfs or massive red giants. The star literally blows apart and unleashes a spherical shock wave that expands outward at more than 22 million miles per hour (10,000 kilometers per second.) Modern astronomers can usually determine which stars caused specific known supernovas. But there is one that still baffles astronomers.