Ejection nebula of supernova Cassiopeia A does not expand evenly

The inner nebula of the much-studied supernova Cassiopeia A is not moving smoothly outward. This has been discovered by astronomers from the University of Amsterdam and Harvard. The astronomers suspect that the remains have collided with something. Their finding have been accepted for publication in The Astrophysical Journal.

from Phys.org - latest science and technology news stories https://ift.tt/D1TV8Io