It follows an ~80 year pattern, with significant changes in luminosity. The change that occurs immediately before the nova is currently underway. Based on historical records, and far more accurate telescopes we could measure it months in advance. It’s pretty cool.

There are a lot of telescopes watching it 24/7 right now, and as I understand it, several of the most powerful have time reserved to immediately watch it as soon as it is detected.

This will be a huge leap in observation of nova. Astronomers don’t fuck around with this sort of event, that’s how well this is predicted.