A supernova is an exploded star. This particular explosion was first observed by people on Earth on October 9, 1604. Famous astronomer Johannes Kep
Cassiopeia A is an exploded star in the Cassiopeia constellation. It is the brightest astronomical radio-wave source in the sky, which means the pre-existing star was a very massive object.
Location Let's elaborate on the exact location. Our Milky Way galaxy is orbited by a satellite galaxy called the