The fantasy universe is full of all kinds of surprises, beyond people's imagination. Among them is such a star, the light and dark changes have "teased" humans for 300 years.
170 years ago, this star became brighter and brighter, reaching the "second brighter" of the entire sky. When people thought it had exploded and perished, it miraculously "survived" and still emits dazzling light like a lighthouse.
This star is Haishan II located in the stellar system of the ship's base, 7500 to 8000 light years away from us. It is also the largest "star" in the Milky Way that humans have observed.
The star suddenly became brighter, and once the "ugly duck turned into a swan"
In fact, people discovered this star as early as 1677. The person who discovered it was Edmund Halley, the famous British astronomer. At that time, it was just a not-bright fourth-class star. Halley did not even take this star seriously. Instead, it continued to study its favorite Comet field, and finally calculated the orbit of Halley Comet , which is famous all over the world.
Haishan 2 is just an unknown junior. So small that few scientists are willing to waste time on it.
However, in 1730, the situation changed. People suddenly observed that the brightness of Haishan 2 had increased a lot, and it became the most dazzling star on the base of the ship.
Just as everyone focused the lens of the high-power telescope on Haishan 2, Haishan 2 was like a shy girl, and the brightness dimmed again and disappeared into the vast universe.
People were extremely surprised: Why can the brightness of this star still flicker and darker? When we were preparing to observe, it hid and disappeared again. Is this sea and mountain second playing hide and seek with us?
However, something even stranger is still to come. By 1827, Haishan II became brighter again, and it became brighter and brighter. By April 1843, it became the second brightest star in the sky, second only to Sirius , which is only 8.6 light years away from the earth.
You should know that Haishan 2 is seven or eight thousand light years away from the earth. If Sirius is a candle that is only 14 meters away from us, Haishan II is a lighthouse that is 10 kilometers away, but the light of the lighthouse is no less than that of a candle, which surprised people.
Why does Haishan II suddenly become brighter? Why did it become dim?
The first explanation that scientists think of is the supernova explosion . Supernova explosion refers to the violent explosion of certain stars that evolve to the end of their lives. This kind of explosion often releases huge energy, and the sudden electromagnetic radiation during the entire process can even illuminate the entire galaxy.
This is not difficult to explain why Haishan 2 suddenly increased its brightness several times or even dozens of times in a short period of time. Moreover, scientists did detect the material ejected from Haishan II, with a total mass equivalent to 10 suns, and it passed through the Milky Way at a speed of 32 million kilometers per second. Isn’t this evidence of a supernova explosion?
However, after careful observation, the scientists found something was wrong. Logically speaking, such a huge explosion, Haishan II should have become dust in the universe long ago? However, except for the sharp drop in brightness of Haishan II, it seems to be unscathed.
Between 1900 and 1940, its brightness was as low as 8 levels and it could not be directly observed with the naked eye. Generally, after a supernova erupts, all the outer material of the star will disintegrate and expand toward the surroundings into nebula, while the core of the star will evolve into a high-density celestial body, and some will evolve into neutron star or even black holes. It is rare to have not been destroyed like Haishan II.
According to the data, some scientists have proposed another hypothesis: Haishan II originally had two partners, which is a system composed of three stars!
is a star moving around a pair of binary stars in the distance. The moment when the two stars are more mass gradually reaches the end of their lives, and when the star is about to end, its volume begins to expand.
But don’t forget at this time, there is also an companion star next to it.According to the law of universal gravitation, the companion star begins to absorb the matter that the expanded star is radiated. When the star expands to 100 times the mass of the sun of , it not only becomes extremely bright, but also releases the accumulated energy and matter outward. The original large-mass star matter was sucked away by the companion star, which lost the original hydrogen outer layer, leaving only a helium internal core.
The mass changes between them, which will naturally affect the star that rotates around them outside. The mass changed, the gravitational balance was broken, and the helium planet was thrown out directly to collide with the third star, causing a big explosion.
Supernova explosion occurred like this. A large amount of matter and dust were thrown around the universe. Because the later substances spread quickly, they quickly caught up with the first substances, and while pushing the substances outward, they were heated and luminous, which made the brightness grow higher and higher. In the end, the two colliding stars merged into one, and the companion star of the original larger star evolved into Haishan II.
Now, scientists have shown that Haishan II may indeed have a companion star, but its companion star should be a hot and smaller-mass star.
If two stars are really combined into one, then its mass should be greater. Therefore, the hypothesis of the three stars proposed above is not enough to satisfy all astronomers. Many scientists believe that the reason why Haishan 2's brightness changes so drastically is actually the reason behind it is the hydrogen element that is making trouble. The higher the hydrogen content released by
, the greater the brightness of the star. Every 1,000 years, Haishan II releases hydrogen equivalent to 10 times the mass of the sun. Of course, the brightness has soared to several times, or even dozens of times as before. They call this phenomenon of Haishan II "fake supernova explosion" .
is unique. When you look at the examples of astronomical observations, similar cases are rare, but they are not unique.
Cygnus P star, whose Chinese name is Tianjin Zengjiu, was discovered by Dutch astronomers in 1600, and the brightness slowly weakened. By 1626, it was completely unseen by the naked eye. But by 1655 it became brighter again, and by 1662 it became darker again, and in 1665 the brightness rose to its peak, and since then it has remained at the brightness of the fifth-rank star.
Similarly, the explosion of SN 1961V, when the substance was thrown out at a speed of 2000 kilometers per second, which is much slower than the ejection speed of most supernova explosions. Its brightness change curve is also significantly different from ordinary supernova. However, scientists are not clear about what caused these "fake supernova explosions". The truth still needs future observations and inferences.
Haishan 2's brightness increased again after 1998, and its brightness has now exceeded the fifth-class star. The increase in brightness shows that Haishan II is consuming its material and energy very quickly.
Scientists generally speculate that Haishan II will eventually become a supernova, but no one knows when its next outbreak will be, it may be a long one million years later, or it may be tomorrow.
Once a supernova erupts in Haishan 2, the gamma ray it emits will inevitably have an impact on the earth. Fortunately, the earth has a dense atmosphere, and these rays are blocked by the atmosphere before they reach the ground.
But the upper part of the atmosphere, including ozone layer , including our space station , and artificial satellite , may suffer a devastating blow. Once Haishan II becomes a supernova, its brightness can even be bright enough to be seen during the day, or at night we can read books based on the light it emits. Perhaps by then, there will be a new sun in our sky.
