Every few months, I see articles about Betelgeuse, the right shoulder in the constellation of Orion, ready to go supernova. The articles vary from the sensational to the apocalyptic and I can understand why it is a fascinating subject. A supernova in our galactic backyard.
So these are the facts: Betelgeuse is a red supergiant and the ninth brightest star in the night sky. It is located between 500 and 643 light years away. Its diameter and mass are riddled with uncertainty. From 1993 Betelgeuse’s radius has shrunk 15%. This is an incredible fact. We have never witnessed such a quick collapse which means that Betelgeuse will soon explode.
But how soon is soon? I wish it was very soon. I want to see a supernova with my own eyes. But we have no way to tell when it’s going to happen. Betelgeuse might have been shrinking for ages, meaning the supernova is imminent or it might have just started which means it has still many hundreds of years to go.
In the end, it is a symbol of how approximate our knowledge is of the star life cycle. But when it will explode it will be a spectacle for ...