Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

Orion may be the first constellation that many friends know, because its position in the winter night sky is much more obvious than that of the Big Dipper, and you can see its existence when you look up!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

And the Betelgeuse on the shoulders of Orion must have left the deepest impression on everyone. This bright orange-yellow star has reached its end of life, and the most brilliant explosion in the universe will greet it in the future. The bizarre dimming event in 2019~2020 once made astronomers very confused, but now a paper on "Nature" has revealed a long-standing mystery!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

Betelgeuse: a star about to die

Betelgeuse is a star about 18-19 times the mass of the sun. It is different from what everyone imagined. For a celestial body like a star, the greater the mass, the faster the burning speed, because its energy comes from the high temperature and high pressure produced by gravitational collapse. The inner core, and the greater mass will make the inner core temperature higher, so the faster the hydrogen fusion speed, and the high enough temperature will make the elements from the helium after the hydrogen to the iron fusion!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

But after helium fusion begins, the star will leave the main sequence zone and gradually become a red giant star! This is because although helium burns at a higher temperature, it is also more intense than hydrogen. Therefore, the outer shell gradually expands to form a red giant or even a supergiant star. The current diameter of stars like Betelgeuse has reached 1180 times that of the sun. Its volume is about 1.6 billion times that of the sun!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

However, the size and brightness of Betelgeuse will change, which Herschel discovered hundreds of years ago, which means that it is already very unstable, and a supernova may occur at any time in the future!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

The reason for the supernova explosion is that the mass of the star is destined. Only stars with a mass of 8-10 times or more are "qualified" to have a supernova explosion. As mentioned above, the Betelgeuse core will fuse to iron, and then it will suddenly stop. The outer shell will collapse under a strong gravitational force, triggering a nuclear-induced collapse supernova explosion, the energy of which is much stronger than the energy released by the sun throughout its lifetime!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

Supernova explosion is one of the most violent energy release events in the universe!

Betelgeuse’s weird dimming moment: how did it happen?

Just as scientists are worried about when Betelgeuse will explode, between 2019 and 2020, Betelgeuse has undergone a strange light change. This is the darkest moment of Betelgeuse's brightness for hundreds of years. Is this a supernova? A sign of an outbreak? Scientists don't know this question either, because supernova models are extremely complicated, and most models set by scientists will not explode, but there are supernovae everywhere in the universe!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

Therefore, the brightness change of Betelgeuse has aroused a lot of attention from scientists, and it has also affected the hearts of countless astronomers. After all, everyone is interested in watching a "close-range" supernova explosion in their lifetime. After March 2020, please participate Aldebaran has gradually returned to normal brightness, disappointing fans waiting for the supernova to explode!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

What causes the dimming?

The team of the Paris Observatory in France and Montargès of the University of Leuven in Belgium pointed the VLT of the ESO (European Southern Observatory) (VLT in northern Chile) at Betelgeuse in Orion at the end of 2019, and obtained extremely fine images. Compared with the earlier and later Betelgeuse (variable stars with different periods in this class, usually up to several years), which returned to normal brightness earlier and later, it is believed that this is caused by the cooling of the surface after a large amount of material ejected by the star has cooled.

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

Emily Cannon of Leuven University stated that “dust emitted from stars at the end of evolution, such as the massive stellar mass ejection we have just witnessed, may become the cornerstone of terrestrial planets and life.”

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

When will Betelgeuse explode in the future? The scientist gave the time!

Although scientists have explained the reasons for the Betelgeuse change, the risk of its supernova explosion still exists, and it may get higher and higher with the increase of time. Therefore, it is still possible for you to see the supernova explosion at "close distance" during your lifetime. Yes, friends who only know astronomy know that this so-called impending eruption and eruption at any time refers to Betelgeuse’s eruption at any time in the next million to tens of millions of years!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

Because any time in the astronomical sense is not timed by the human life cycle! But the question is, maybe Betelgeuse has already erupted, it is about 600 light-years away from the earth, maybe the light of supernova explosion will arrive tomorrow?

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

But scientists still have to pour cold water on everyone. Dr. Meridith Joyce from the Australian National University (ANU) led a team to conduct a very in-depth study on the strange light changes of Betelgeuse. He It is believed that despite the sharp change in brightness between 209 and 2020, Betelgeuse may still be in the early stage of helium combustion in the red giant, and it is still too early for the supernova to explode!

Dangerous Betelgeuse: 1.5 billion times bigger than the sun, may explode at any time? The scientist gives the time

The Orion of the future?

After a long time, Betelgeuse is still in the early stage of a red giant star, will it become even bigger in the future? It's 1.5 billion times now. How big is the future? This is an excellent feature!