Cassiopeia A (First Light)
October 19, 2005
Cas A is the remnant of a star that exploded about 300 years ago. The X-ray image shows an expanding shell of hot gas produced by the explosion. This gaseous shell is about 10 light years in diameter, and has a temperature of about 50 million degrees.
Topics: Cassiopeia A, Cassiopeia constellation, Supernova remnants, hot gas, X-ray, Shell, Cassiopeia, Supernovae, Star, Science