The Bureau of Astronomical Telegrams sent out a telegram about Betelgeuse.
The Bureau of Astronomical Telegrams - the most authoritative source of astronomy news in the world - has never allowed itself artistic expression in my memory. But the other day observatories around the world received a telegram with the headline "Betelgeuse fainted." Astronomers are shocked, and the star in the constellation Orion seems to be shocked too. You don't need a telescope to be convinced of this, you just need a clear night.
Even before this telegram, many amateurs, including people who can barely find their way in the starry sky, noticed that something was wrong. Autumn came, and the huge, bright constellation Orion rose higher every evening in the east … but it was somehow different. Looking closely, people understood: the brightest star of this constellation, the one on the left "shoulder" of Orion, became dim. This immediately changed the pattern of the constellation, made it unusual. Yes, this is the very star that can explode at any moment and destroy all life on Earth. What's going on and how big is the threat?
First, let's take a look at Betelgeuse for ourselves. People who know how to find the Ursa Major, know how to find the constellation Orion, it is difficult not to notice it. In the evenings, it stands low above the eastern horizon, by midnight it rises above the point to the south. Three stars, lined up in a row, form the belt that Orion is girded with. A "sword" hangs from his belt, in which even a not very keen eye will see a nebula, a cloud of dust illuminated by stars. At the bottom there are two legs, at the top there are two stars, denoting, as it were, the shoulders. The left, raised up (Orion, as it were, swinging at someone) - is Betelgeuse. It actually bears the official name "Alpha Orion". Alpha is the first letter of the Greek alphabet, which means that Betelgeuse is the first brightest in the constellation. But now it looks dull and kind of smoldering. Its usually bright red color is more like coals,which are about to go out. Obviously something happened there.
Betelgeuse is a very large star, it is 11 times heavier than the Sun, almost 900 times larger than the Sun, and shines a hundred thousand times brighter. This is her misfortune, such stars do not live long. Its age is only 8-10 million years, and it is already dying, for comparison - the age of the Sun is 4.5 billion years, and it is still doing well. By the way, this means that dinosaurs, yes that dinosaurs, the first primates from which a man turned out, saw Betelgeuse appear! How will she die? Very bright. Although the light from Betelgeuse takes 650 years to reach us, there are stars and closer, it will explode so that it will eclipse the full Moon in our sky. And it would be okay to eclipse, well, there will be two moons, beautiful. But together with optical rays, a colossal amount of radiation will fall on our planet. We have never seen an event of this magnitude. And we don't know for surehow it will look and how it will turn out.
Such big stars don't last long.
When will this happen? Usually, experts say: "this may happen tomorrow, or maybe in thousands of years." According to the latest research, there are about a hundred thousand years left before the explosion. But all such calculations are based on our knowledge of the structure of this star. And our knowledge can be limp, and "fainting" is another evidence of this.
Actually, Betelgeuse changes brightness, this is not news. And he does it without a clearly defined period. Such fluctuations just indicate that the star is ending its life path. Look at the sun - it shines evenly. In the 19th century, this star shone very brightly, it was then that it was assigned the index "alpha", because it was the brightest in Orion, and the sixth brightest in the entire sky. Now there is nothing to see. The star pulsates with a frequency of about 400 days, and recently the period has grown to 420 days. There is also a longer pulsation with a period of about 2 thousand days. Apparently, the pulsation minima were superimposed on each other, and the brilliance "collapsed". The Bureau of Astronomical Telegrams reports that Betelgeuse has never been so weak.
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Does this mean that the explosion will come very soon? The popular press is trying to reassure: the star will certainly explode, but hardly before our eyes. In fact, "fainting" means just that. A few words about how it works. Before the explosion, the star sometimes expands - while its temperature drops, so does the luminosity. It shrinks - the temperature and shine increase. The critical phase is precisely the expansion phase that we are seeing now. The star collects the remnants of nuclear fuel, it burns very quickly inside the star, because of this, it expands. But there is little fuel, there is already nothing to support combustion in the new "body". Therefore, the star cools down, and the forces of gravity collapse it. An explosion is simply a very fast implosion, so fast that the star does not have time to turn on the nuclear reactor (or there is no more fuel at all), and cannot stop the collapse. The forces of gravity would compress the star to a point. But the explosion produces such an amount of energy that forces other than gravity are included. Bottom line: most of the star in the form of light and radiation is emitted into space, the smaller part turns into a black hole.
So: the fact that the star has expanded greatly suggests that now it will collapse just as rapidly. If it doesn't taxi, we'll see a supernova explosion in a few hundred days. To be honest, this scenario is hard to believe. Intuitively, Betelgeuse still has gunpowder in her flasks. But the Bureau of Astronomical Telegrams calls to be on the alert. And that means we need to make ourselves a habit. Went out for a walk with the dog, is the evening clear? Okay, looking for the Alpha Orion. How is she?
EVGENY ARSYUKHIN
