In the vicinity of our solar system, a huge star is about to explode. A “only” 640 light years away, in fact, the red supergiant Betelgeuse is about to become a supernova, one of the most violent and energetic events of all that occur in the Universe.
Betelgeuse is, today, the brightest star in the constellation Orion, and is perfectly visible from the northern hemisphere of the Earth. Of a characteristic orange-red color, the star has been occupying the twelfth position in the list of the brightest. However, and in just a few years, this authentic star giant, more than 20 times more massive than the Sun, has been losing brightness rapidly, until descending, in record time, to position 21 of the list. That is why many astronomers have begun to speculate about its explosion, which for many is imminent.
The end of the red supergiant
We know that when a star reaches the red supergiant stage, as is the case with Betelgeuse, its existence comes to an end. In this phase, in effect, the perimeter of the stars grows enormously, and then suffers a collapse that will cause it to explode as a supernova. At present, Betelgeuse has a radius that is approximately 900 times greater than that of our Sun. To give us an idea, if it were in our solar system its perimeter would reach almost Jupiter …
Given its size and relative closeness, Betelgeuse is also the only star, apart from ours, whose surface can be studied in detail. Thus, astronomers have been observing their “convection cells” for years, currents of colder stellar material that sink into the depths of the star at the same time as the hotter material emerges to its surface.
The size of each of these cells is really gigantic, and when they move, they interact with Betelgeuse’s magnetic field. And since the heat of a star’s surface is what determines its brightness, Betelgeuse is now less bright because the number of dark, colder spots has increased.
At any time in 100,000 years
However, the star is large and bright enough to be observed with the naked eye, without the need for telescopes. And an attentive observer could, without using any instrument, have noticed Betelgeuse’s sudden decrease in brightness just by comparing it to that of other stars. With today’s powerful telescopes, of course, the information is much greater, and that is why many astronomers believe that the red supergiant is about to become a supernova. In fact, he is the closest candidate known in the process of doing so. But when exactly? At any time within the next 100,000 years, a simple blink compared to the billions of years old of the star.
Astronomers cannot be more precise because the details of how a star’s brightness varies just before the explosion are still unknown. So, just in case, they don’t take Betelgeuse’s eyes off him.
An unprecedented show
For some, the outbreak is imminent. And when it happens, Betelgeuse will become the brightest supernova ever observed by humans. In just a few days, it will become brighter for us than the full moon, it will be perfectly visible even by day and, at night, its light will be able to cast shadows.
If Betelgeuse continues to get dark, it would be another symptom that his situation is critical. At the current rate, the star would cease to be visible in just six years, forever altering the “landscape” of the constellation Orion. Later, and without warning, the star would explode, and humanity would witness a celestial spectacle that very few members of our species have had occasion to see. .