If a star went supernova, would we know before we actually saw it?

Answer 1

We might, but not by much. There is a neutrino surge before the actual vast increase in brightness, so if our neutrino detectors were recording it is possible that they would arrive before we actually noticed the increase in brightness.

Moreover, if the supernova happened deep in a dust cloud, the neutrino surge might be the only telltale sign we would have. The light would not be notable at all. Sort of a muffled blast!

HTH

Charles

Answer 2

We know the stages previous to the supernova formation, but they take too much time for a prediction being useful.

We can detect when a massive star is ceasing to generate energy (what announces its collapse under the force of its own gravity), or (the other type of supernova origin) when a dwarf star is accumulating too much material from a companion star, but those are processes that take thousand of years. So t he supernova explossion is always a surprise.

Answer 3

Well actually, we probably wouldn't know about if for several thousands of years (depending on the distance). Supernovas are big events, but it takes the light many years to get to earth so it's possible that we would miss the actual explosion, but be able to see the light as it eventually worked its way through space and passed by the Earth.

Answer 4

Since the speed of light is the fastet speed possible, no.
Nothing else would "get the word out" any quicker.

Answer 5

The visual explosion would be preceded by a dense mass of neutrinos,if we could detect them this would be an indication.

Answer 6

I agree with Charles.

Answer 7

No.