Astronomers are predicting that they will combine in 2020. Thus creating a red nova that will be visible to the naked eye here on earth. The stars are about 1,800 light years from earth.
My question is; if we do indeed see this red nova here on earth in a few years, doesn't that mean that it already happened? Like about 1,800 years ago?
And, if that is true, is there no other way for us to know if this has already happened other than observing the light produced by the red nova?