> it is almost certain that it has already gone supernova.

No it's not, stop spreading misinformation. It's only ~500-600 light years away and most models expect the star to live another 10,000-100,000 years, and even models where its remaining lifetime might be zero are just saying "at some point in the next few (ten) thousand years", with a small probability of the next 500-600. See e.g. this modeling from February, and in particular table 3 in it.

We cannot rule it out, but it looks very unlikely.