This article comes from WeChat Public number: Tencent Space (ID: qqtaikong) , translation: Yu Jia, the picture from: ESO / Digitized Sky Survey 2

参 宿 四 (Betelgeuse) is a red supergiant star in Orion. It used to be the 12th brightest in the night sky except the sun. star.

Legend: The place of residence is located on the shoulder of Orion (red circle position). Orion is a well-known constellation of the starry sky in winter, very recognizable

But according to foreign media reports, the star has been dimming in recent months. This may be a signal of an explosion, but it may also be just another physical phenomenon.

Sansu 4 is about 8.5 million years old. Because of its brightness and color, it has always been one of the most recognizable stars in the sky. However, since October last year, the star has been half darker, dimmer than at any time in a century.

Shenzhu is 642.5 light years away from Earth. If it really becomes a supernova, its brightness may be comparable to that of the moon in a few weeks or even longer.To brighter. At the same time, this will be the closest supernova to Earth as observed and recorded by humans.

Because it takes time for the light to propagate, if we see the explosion of Sansui tonight, it means that this supernova will be born more than 600 years ago.

Edward (Edward Guinan) , who reported this in the Astronomer Telegraph, said that the star will become extremely bright when it erupts, That makes it difficult to see other stars nearby. Edward is a professor of astronomy and astrophysics at the University of Villanova.

Can our generation see it?

Four masses are 20 times the mass of the sun, and they are also a variable star. In other words, their brightness will change naturally. This is a phenomenon observed by scientists for decades. But accelerating dimming and not stopping usually means that the star is cooling and expanding, and then it explodes.

Legend: The scene of the four explosions described by the artist

Sarafina, a graduate student in astronomy at the University of California, Berkeley, who studies the four stars and the stellar explosion (Sarafina Nance) When will the star burst?

Edward said that Humans did not observe them closely until the supernova broke out. He also said that “there is no real consensus yet.” Some people think that major changes in stars will not be visible until a few hours before the explosion, while others believe that the stars will start to darken about a year before the explosion.

Both Sarafina and Edward believed that the Venus 4 could explode at any time within 100,000 years, but there may be other reasons for the decrease in the brightness of the star.

A surprise?

Darkening means that the explosion may occur in a relatively short time. “I don’t think it will explode now,” Edward said. “I hope it will burst, but I bet it is not now, it will be brighter again.”

Edward said that it would be awesome to see a supernova explosion on this huge star close to us. However, there may be other reasons for this dimming.

Legend: Artistic rendering of the observations of the participants 4 by the European Southern Observatory’s very large telescope. As shown, the gas plume of the star is almost the size of the solar system

According to Sarafina, Darkening may be due to some physical processes inside the star. She explained that different parts of the star may have different densities, and this density instability will cause energy to fluctuate inside the star, transferring energy from the inside to the outside. This causes a change in brightness and can cause stars to grow or shrink.

Salafina added that the extreme drop in brightness may also be due to the magnetic activity of the stars. But she said it was difficult to model the activity through numerical simulations, so she was not sure whether magnetic activity was a clear factor. She also added that it is possible that the material ejected from the star is forming “a kind of dust mist”, making it fuzzy and dim.

If there is no explosion recently, it may be less interesting to the public. But Sarafina said, “How do massive stars undergo cycles of change? It would also be interesting to understand and observe from a physics perspective.”

Looking up at the stars

Sarafina and Edward acknowledged that the darkened appearance of Sansui is probably just some interesting stellar physics. But they also agreed that the star could still explode in our lifetime.

Edward said that before the explosion, such changes were usually so slow that they could not be observed well, but now it is really great to see the evolution of stars.

Salfina said, “We don’t know what will happen. Our model must be limited. I don’t think it will explode anytime soon, but I will pay close attention. Every time I go out, I will look up at the night sky and look at the hostel. Is it still there. “

This article comes from WeChat Public number: Tencent Space (ID: qqtaikong) , translation: Yujia