According to various observations since October last year, the brightness level of Betelgeuse, one of the most characteristic and brightest stars in our sky, has dropped considerably and this has led some people to fear that it may explode soon. Betelgeuse, in fact, will die with the most classic of explosions, a supernova, but before this final explosive phase will tend to darken and then collapse on itself and perform the explosive “bounce”.
The star, only 8.5 million years old, is 642.5 light years away from us. If a star of this size (it is a red supergiant with a mass equivalent to at least 20 suns) exploded it would be clearly visible in the sky. It would result in the closest supernova ever observed and recorded by humans and would exceed, in terms of brightness in our sky, even the supernova of 1054 AD that led to the formation of the Crab Nebula whose star, however, was 6523 light years away.
Of course, it’s always worth talking about objects so far away: Betelgeuse could have already exploded but we would only know in hundreds of years since the star’s light takes 642 years to reach us. As Edward Guinan, professor of astronomy and astrophysics at Villanova University who speaks on Space.com, explains, the supernova would be extremely bright in our skies.
However, astronomers tend to contain the excitement for such an event since we are still facing a variable star, a star whose brightness increases and decreases over time by definition. However, it should also be noted that the last level of darkening has gone beyond what was previously predicted, which is why some astronomers have thought that we might be facing pre-explosive phases.
The problem also lies in the fact that the direct observations of stars just before exploding in a supernova were very few and we basically don’t know what really happens and this is also reflected in the lack of consensus of astronomers regarding the possibility that Betelgeuse is really going to explode. It could be a false alarm and the explosion could happen, for example, in 100,000 or a million years.