Hi Connor,
There are also longer term changes to older nearby supernova remnants that are studied.
The best example is M1 the Crab Nebula. This was created by a supernova in our galaxy in 1054. Images taken over several decades reveal the expansion of the nebula.
There is also the more recent supernova 1987A in the Large Magellanic Cloud. A bright ring of material that was ejected prior to the supernova was illuminated by the explosion. Though professional observatories are needed to observe it.
Andy