The headline at this link is, why have so few Milky Way supernovas been observed over the last millennium? See https://phys.org/news/2021-01-milky-supernovae-millennium.html … a mystery as our galaxy is thought to experience several supernovae each century = 3000 events over a thousand years. Yet, it is hundreds of years since the last observable supernova exploding [as far as humans recording such an event]. The lone one was back in 1604, mentioned by astronomers around the world. Or rather, it has been interpreted as a supernova explosion. The link goes on to say that back then nobody knew what caused them to switch on, and off. Nowadays, we do, they confidently assert. They were the result of the death of a star – or a runaway event on a white dwarf.
They go on to say the absence of observations is due to the location of observers on earth. See the web site https://arxiv.org/pdf/2012.06552.pdf … However, I can remember reading quite some while back that Polynesian chiefs were often named after peculiar astronomical events during their early lifetimes and one of those events are thought to be not just the appearance of comets and meteors, but nova and supernova [or once again, what are interpreted by the investigators as supernova]. Perhaps the people in the study have not been looking in the right place for a mention.
In Electric Universe theory supernovae are explosions of energy as a result of Birkeland currents. A high energy event. This might explain the recent mystery where a suspected supernova in another galaxy miraculouslly sprung back into life a few decades later than the first explosion of energy. Just a thought.