Chapter 124 The Situation Inside the Hydrogen Envelope of Betelgeuse

In southern Yunnan and the Observatory Observation Array Center, Xu Chuan found several doctoral fellows from NTU.

At this moment, these people were discussing something fiercely in a laboratory. On the side, there were several scientific researchers from the Observatory Observation Array Center, who were also discussing something simultaneously.

Without making a sound, Xu Chuan slowed down and leaned over to listen.

"Perhaps it is caused by the asymmetric envelope activity of Betelgeuse. The data in this area is indeed abnormal compared with other observational data."

"I have checked the original observation data and compared it with historical data. From the infrared spectrum analysis data, this abnormal observation data is not eye-catching in history. More abnormal data than this have been observed on Betelgeuse. ”

"For example, in 2007, the astronomical observatory in the country where the sun never sets observed the abnormal expansion of Betelgeuse. At that time, the overall shape was stretched from the standard circle of a table tennis ball into the shape of an egg."

"I know this incident. Later analysis is that the activity of Betelgeuse caused the gas envelope to expel a large amount of material outwards."

"So I think there is nothing wrong with the data. The problem most likely lies in the data calculation. Calculating a star with two hugely different diameters is unscientific and directly violates common sense."

"."

"Ah, Xu Chuan is here."

While they were discussing, someone suddenly noticed Xu Chuan squatting aside and exclaimed.

This made the colleague who had just questioned the problem with the data calculation blush slightly and feel a little embarrassed. After all, it was not good to say that there was a problem with his calculation behind the back of the real owner, and the real owner heard it.

Xu Chuan didn't care and didn't care. It was normal to have doubts.

To engage in scientific research, a questioning spirit is essential.

It is precisely because of the rigor of scientific research that it is more necessary for someone to question whether the process and results are correct.

The more basic the subject, the more people need to stand up.

And what he did was indeed a bit outrageous.

Two diameters of a star are calculated. Not to mention those workers in the astronomy department, even if they are Fields Medal winners, Fehrman or Witten, their first reaction is probably that there is a problem with the calculation data or calculation formula. .

Therefore, Xu Chuan has no objection to other people's suspicions, as long as the results of the discussion are finally available.

"It's okay, don't worry about me. I care more about the results of your discussion? How is the verification of the observation data? Is there a problem with the observation data, or is there something abnormal about Betelgeuse?"

Xu Chuan waved his hand and motioned for everyone to continue.

On the side, Liu Xuan, who led the team from Nanda, shook his head and said: "There hasn't been much progress. We can't determine where the problem is."

"However, there are several situations where problems may arise. I can list them."

"Which ones?" Xu Chuan asked.

Liu Xuan: "The first one may be caused by the asymmetric envelope activity of Betelgeuse. Because Betelgeuse has reached its old age, the outer hydrogen envelope is constantly expanding, but at the same time, its inner core is The activity is intense, so the hydrogen envelope appears differently, causing problems with the observational data."

"The second possibility is that Betelgeuse's violent activity caused the huge crown plume of gas ejected from the surface to form an effect similar to the expansion of a star."

"The third possibility is that there is something wrong with your data calculation, little junior brother."

"The fourth type may have a companion star orbiting it in its gas envelope, and part of the observed data may come from its companion star."

"The fifth type, there may be a planet orbiting it in its gas envelope."

"Sixth Type"

Liu Xuan listed the possible situations. Xu Chuan listened quietly. After he finished speaking, he raised his head and said, "Can you tell me the details of the fourth and fifth companion stars?"

"Yeah, no problem."

Liu Xuan nodded and continued: "The first time humans accurately observed the star Betelgeuse was when large telescopes and radio telescopes appeared. It was less than fifty years ago."

"And fifty years ago, parameter four was already in its old age."

"A star continues to expand as it enters its old age, take our sun as an example."

"When the sun enters its later years, most of the hydrogen in the central region will have finished reacting, and the rate of thermonuclear reactions will immediately decrease sharply. At the same time, the balance between gravity and radiation pressure in the central region will be broken, and gravity will gain the upper hand. "

"At this time, the central core began to shrink and gradually became hotter and denser. At the same time, the outer layers expanded violently due to the energy released by the contraction of the core, and turned into a red giant."

"At the same time, the Sun's outer shell will continue to expand outwards, while the core will compress inward and become, eventually, a red giant in its later years and eject its outer layers to form a planetary nebula."

"According to calculations, the sun will spread to the edge of the earth in its later years. In the process, it will swallow up all the surrounding materials, such as Mercury, Venus, the earth, etc."

"Betelgeuse is currently in this stage. Its surface layer, the hydrogen envelope, has been spreading outwards, and its volume and diameter are also increasing."

"At this stage, if there is another star near Betelgeuse and it is not destroyed in the process of being swallowed, it will fall into Betelgeuse's hydrogen envelope."

"If its own mass and orbital speed can counteract the gravity of the core, it will rotate around the core in the hydrogen envelope, and then form a relatively unique binary star system, that is, the small star becomes a planet-like and rotates around the main star."

"This may explain why there are two diameters you calculated. Some of the observed values ​​may actually come from this small star."

"But this statement is relatively... Well, it can only be said that the current astronomical community does not have enough evidence to support it. It is just a hypothesis made by other researchers in the astronomical community in the past regarding the unusual celestial activity of Betelgeuse."

"As for the planets, they are similar to the situation of the companion stars. They are all swallowed up, but the probability of a planet existing is relatively small, because they do not have such a strong gravity to counter the stellar wind, and they will eventually fall into the core of Betelgeuse."

"So the probability of a planet existing can be basically ruled out."

Liu Xuan roughly explained the so-called binary star system. Although binary star systems are very common in the universe, he is not very optimistic about this hypothesis.

Because of the distance and the formation of stars.

The formation of a single star system is relatively simple. It is that the matter, dust and some gases in the universe accumulate over time to form a gathering point, and finally gather into stars under the action of gravity.

For binary stars, there are more dust and matter in a certain place in the universe, and they are widely distributed. It is possible to form two gathering points, that is, two accretion disks, and finally form two stars over a long period of time.

If the mass of the two stars and the distance between the stars are sufficient, then a stable binary star system can be formed. More than one-third of the galaxies in the Milky Way are binary stars.

But Betelgeuse does not meet this condition.

Because the distance is too short.

Even if its size is placed in the solar system, the boundary is enough to swallow Jupiter, but on the scale of the universe, if there are two stars squeezed in this range, it is no different from being next to each other.

But in the stage of star formation, gravitational collapse will clear all objects around.

Massive stars like Betelgeuse will eat up all the raw materials around them after they are formed.

Even if there are still enough raw materials nearby to form a small star, it will gradually fall into Betelgeuse due to the influence of huge gravity and eventually disappear.

You should know that the diameter calculated this time is a Betelgeuse that is 890 times the diameter of the sun, while the other is an unknown star that is only 67 times the diameter of the sun. The difference between the two is huge.

The gravitational difference between the two is like an elephant pulling a river with an ordinary person.

The final result is only one, that is, the ordinary person is dragged.

In addition, there is no evidence in the current astronomical community to show that Betelgeuse is a binary star system.

In the past few decades of observation and observation of Betelgeuse, no trace of its companion star has been found.

So Liu Xuan is not very optimistic about the statement that there is another star rotating around the core of Betelgeuse in the hydrogen envelope of Betelgeuse.

He thinks the most likely possibility is that the observation data is abnormal due to the violent activity of the hydrogen envelope, or that the calculation formula of this junior brother is wrong.

Xu Chuan pondered for a moment and asked, "If it is such a binary star system, then it should have a return period, right?"

"Just like the moon revolves around the earth and returns to the full moon every month."

Liu Xuan nodded and said, "If this kind of stable physical binary star system really exists, the small star must have a return period."

"But we can't be sure how long it takes for this 'hypothetical' small star to revolve around Betelgeuse."

"Maybe a week? A month? Or maybe a year? Or even more than ten years?"

Xu Chuan: "Can you calculate an approximate time?"

Liu Xuan smiled bitterly and said, "I don't know. No one has ever thought about it, and no one has tried it because of the lack of necessary data."

"You know, the revolution speed of a planet depends on the gravity of the star it revolves around, and the distance"

Before Brother Liu finished speaking, Xu Chuan understood what he meant.

This is the basis of physics.

Universal gravity is proportional to mass. The greater the mass, the stronger the gravity. It is inversely proportional to distance. The farther the distance, the smaller the gravity.

For example, the Earth is subject to the gravity of the Sun. When it approaches the Sun, the Sun itself rotates, causing the Earth to revolve with its gravity.

While revolving, centrifugal force is generated between the Earth and the Sun. The centrifugal force counteracts the gravity of the Sun, and this counteraction is proportional to the distance from the Sun.

The closer to the Sun, the stronger the gravity.

In order not to be directly attracted to the star by the gravity of the star, the planet will revolve faster, thus forming a greater centrifugal force to counteract the gravity of the Sun.

In the galaxy that can finally stabilize, the centrifugal force and gravity between the planets are in a state of balance.

This is why the Earth will not be sucked into the Sun.

According to this theorem, after determining some conditions such as distance and mass, the revolution speed of the planet can be calculated.

But now the problem is here. If there is really a small star in the hydrogen envelope of Betelgeuse, then how far is it from the core of Betelgeuse and how much mass it has, no one knows.

Because when people observed Betelgeuse, it was already in its old age and had already swallowed up the "possible" star.

Therefore, there is no way to calculate the mass and orbital speed of this companion star.