The Cassiopeia A Supernova Was of Type IIb
The Cassiopeia A Supernova Was of Type IIb
Cassiopeia A is one of the youngest supernova remnants known in the Milky Way and a unique laboratory for supernova physics. We present an optical spectrum of the Cassiopeia A supernova near maximum brightness, obtained from observations of a scattered light echo - more than three centuries after the direct …