What had happened in the fall of 2019 was the expulsion by Betelgeuse of a huge amount of material — enough to obscure part of the star from our eyes, and give the impression of this loss of luminosity. But the causes of this expulsion are deeper and probably explain why the star has not yet recovered.
The 2019 event is believed to have occurred when the star was at the peak of its 400-day cycle, coinciding with the appearance of a hotter region on its surface. The resulting expulsion of material was billions of times that of the most massive flares from our Sun. Which explains that it is apparently, even today, “unbalanced”: it has lost its cycle of “beats” of 400 days that we have known about it for two centuries. For the moment, this rhythm seems to have accelerated. and its surface oscillates in an abnormal waynote in their study astrophysicists from the Harvard-Smithsonian Center for Astrophysics and institutions from two other countries.
But beyond the astronomical curiosity that all this represents, Betelgeuse is not in good health: it is a massive star – a red supergiant – approaching of his inevitable end of life. Some theorists predict that it will die in a final explosion—a supernova—likely to occur in “only” 10,000 years. Others place a more distant date, or speculate on a less spectacular death. In any case, the fact that it is in our vicinity – just 430 light years away, in the constellation of Orion – offers a rare opportunity to observe these strange phenomena. Another mass expulsion of matter is thus planned for 2026.
The worst-case scenario — a supernova — is not a risk for us: it would take for that be 10 times closer. But the spectacle is likely to be impossible to miss in the sky.