What does the sun's closest neighbor look like? Are there Trisolarans on Proxima Centauri?

Proxima Centauri is the closest star to the solar system. The Trisolarans in Liu Cixin's novel "The Three-Body Problem" are intelligent life forms living in such a system. Of course, this is just science fiction, but many science fictions are scientific predictions about the future. So are there really Trisolarans there?

Let’s dissect this Samsung system today and see what it looks like.

Proxima Centauri is the youngest of the three stars.

Alpha Centauri is also called Alpha Centauri. It is a triple star system consisting of three stars, Alpha Centauri A, Alpha Centauri B, and Alpha Centauri C. I will sometimes refer to them as Alpha Centauri A, Alpha Centauri B, and Alpha Centauri C. Don't get confused. This triple star system is about 4.3 light years away from us.

The masses of the three brothers are: the eldest is about 1.1 times that of the sun, and the second is about 0.9 times that of the sun. That is to say, the two brothers have similar masses to the sun, and their surface temperatures and brightness are also similar. The eldest is slightly brighter than the sun.

As the saying goes, the nine sons of a dragon are all different. The third son was born in the same star system as the first and second sons, but they are as different as Wu Song and Wu Dalang. The third son, C, is just a red dwarf, very small, with a radius less than 1/3 of the sun, about 200,000 kilometers, a mass only about 12% of the sun, a surface temperature about half of the sun, and a brightness of 1/18,000 of the sun.

The absolute magnitude of Alpha Centauri A is 4.45, and the apparent magnitude is 0.01; the absolute magnitude of Alpha Centauri B is 5.71, and the apparent magnitude is 1.33; the absolute magnitude of Proxima Centauri is 15.49, and the apparent magnitude is about 11. The smaller the magnitude, the brighter it is, and the more negative the value, the brighter it is. The brightness difference between each magnitude is 2.512 times, and the lowest magnitude that the human eye can see is 6.

From this we can see that the first and second stars of the Antarctic are very bright stars visible to the naked eye in the night sky, and they rank 6th and 20th respectively among the bright stars in the sky. Although the third star, Proxima Centauri, is the closest to us, it cannot be seen by the naked eye.

The positions and movement patterns of the three brothers of Nanmen II

The current position of these three stars is that the third one is the closest to us, only 4.24 light-years away, so people call it Proxima Centauri, which means the nearest neighbor. Star A and Star B are farther away from us, about 4.37 light-years away.

The motion pattern of these three stars is that the first and second stars orbit each other, while the third star orbits the first and second stars, with an eccentricity of 0.5179. The distance between the first and second stars is about 35.6AU (astronomical units), or 5.33 billion kilometers, which is less than the average distance from the sun to Pluto; and the distance between them is only 11.2AU (1.68 billion kilometers), which is only equivalent to the distance between the sun and Saturn.

Saturn and Pluto are both planets in the inner solar system, but Alpha Centauri A and Alpha Centauri B are two stars comparable to the sun. They orbit each other at such a close distance that the gravitational effect between them can be imagined. The orbital period of the two stars is about 79.91 Earth years.

Proxima Centauri orbits around the two stars A and B. In the early years, there was controversy in the scientific community as to whether Proxima Centauri belonged to this star system. In 2017, a scientific team made precise measurements of Proxima Centauri's radial motion, thus confirming that Proxima Centauri orbits around the two stars A and B, making Proxima Centauri the younger brother of this triple star system.

It takes Proxima Centauri 547,000 years to orbit around Stars A and B, with an eccentricity of about 0.5. Its farthest distance from Stars A and B is 0.22 light-years (13,000 astronomical units), which is about 1.95 trillion kilometers.

Humans still don’t have an intuitive understanding of exoplanets

Is there life on Alpha Centauri? We cannot be sure of that yet. Not only can we not go to the site to see it, but even with the largest telescope we cannot see what it looks like there. The minimum resolution angle of the human eye is about 1' (1 arc minute), which means that no matter how far or near the object is, it must have an angle of 1' when it reaches the human retina. 1° (1 degree) is 1/360 of a circle, and 1' is 1/60 of 1°. It is only with such a large angle that the human eye can distinguish.

Since stars are too far away from us, the closest one is more than 4 light years away, almost all stars cannot be distinguished as circular surfaces when they reach the human eye. Even with the most advanced astronomical telescope, it cannot be enlarged to an angle of 1', so only a bright spot can be seen. So far, the only star that seems to have a circular surface is Betelgeux, because this star is not too far away from us, but its diameter is thousands of times that of the sun.

Therefore, the more than 4,000 planets discovered by humans outside the solar system were not "seen" but "guessed". Some people may say that scientists are just like me, guessing blindly. In fact, scientists' "guesses" are not random guesses, but calculations.

How astronomers search for planets outside our solar system

There are two main methods for observing exoplanets: the transit method and the gravitational perturbation method. Both methods require the use of high-tech astronomical telescopes.

The transit method is that when a planet happens to move in the middle of people's line of sight to observe a star, it will affect the brightness of the star. By calculating this influence and the period of light variation, we can know whether it is a planet, its approximate size, its distance, and its orbital period.

The gravitational perturbation method is based on the law of universal gravitation. The gravitational interaction between stars and planets will cause certain changes in the motion of stars. Based on the size and period of this change, the mass and distance of the star, as well as related parameters of its movement, can be calculated.

The combined use of these methods can produce quite accurate results. That’s why there are often reports of finding the Earth’s first and second cousins, but most of these “relatives” are far-fetched, and no one knows how similar they are.

However, although these methods can calculate the approximate distance between the planet and the star, and thus determine whether it is in the habitable zone, they cannot see whether there is life there. Even if it is in the habitable zone, it does not necessarily breed and evolve life. For example, Venus and Mars have entered or had the opportunity to enter the habitable zone of the sun, but no life has been born.

Only civilizations above level 2 can be detected by us.

With the current technology, we cannot observe life outside the solar system, let alone life with a civilization like ours. Only when this civilization can affect the movement and light changes of stars, such as by creating a Dyson sphere to wrap around a star, can it be discovered through observation. This kind of civilization must be at least level 2, and scientists have assessed that human civilization is only level 0.73.

Voyager 1, launched by NASA in the 1970s, took a stunning photo when it was 6.4 billion kilometers away from the Earth. In the vast space, the Earth became a dark spot of only 0.12 pixels in size, smaller than a speck of dust in the sun. On this speck of space dust, there are more than 7 billion people eating, drinking, defecating, urinating, fighting for power, and being jealous. It is terrifying to think about it.

The nearest star is 4.3 light-years away, which is 6,356 times the distance of 6.4 billion kilometers. Even the largest modern telescope cannot see this grain of dust. How can we know whether there is a civilization like human beings out there, or even more low-level life forms than this?

Therefore, whether there is life in the Alpha Centauri star system remains to be guessed.

The basic theory now holds that life cannot exist on stars and can only originate on planets. No planets have been found around the eldest and second stars of Alpha Centauri. They only have a circumstellar disk, that is, a dust disk formed around the equator of the star.

The total mass of these dust particles is about one millionth to one ten-millionth of the mass of the moon. The mass of the moon is 1/81 of the earth. Therefore, if all these dust particles condense into a ball with the density of the moon, its diameter will be only 16 kilometers. It is impossible for life to be born on such a ball.

On the other hand, Proxima Centauri, the younger brother of the two, has two planets discovered. According to the naming rules of planets, they are named Proxima b and Proxima c. Proxima b has a mass of about 1.17 to 1.3 times that of the Earth and is a rocky terrestrial planet. It is about 0.49 AU (7.35 million kilometers) away from Proxima Centauri and has an orbital period of 11 days. Proxima c has a mass of about 7 times that of the Earth and is a gas planet. It is considered to be a mini Neptune, with an orbital radius of about 1.49 AU (223.5 million kilometers) and an orbital period of 1928 days (about 5.28 Earth years).

So is there life on these two planets? Let's analyze it.

Proxima b is the most likely star to harbor life

Because Proxima b is in the habitable zone. The so-called habitable zone is the distance between the planet and its parent star. The radiation from the star allows the planet to maintain a temperature that is neither too hot nor too cold. This temperature is suitable for the existence of liquid water. Since Proxima Centauri has a low luminosity and temperature, the temperature is suitable at a distance of 7 million kilometers.

Since it is in the habitable zone, some scientists believe that there may be life on this planet. But the fact is that Proxima b is too close to Proxima Centauri and has long been tidally locked, that is, one side is always facing Proxima Centauri and the other side is facing away from Proxima Centauri. In this way, one side is always in daytime, baked by the hot radiation of the star, and the temperature is always maintained at hundreds of degrees Celsius; while the other side is always dark, in the extreme cold of more than minus 100 degrees Celsius.

Therefore, even if life can really be born on this planet, it can only be in its twilight zone, which is the boundary between day and night. The temperature in that area can reach above 0°C, so liquid water may exist.

But even if there is life, the environment in which it exists is very harsh

Although Proxima Centauri is older than the Sun, about 4.85 billion years old (the Sun is about 4.6 billion years old), the Sun is already middle-aged, while Proxima Centauri is still an infant. This is because Proxima Centauri has a small mass and its central nuclear fusion is much milder than that of the Sun, so its fuel consumption is very slow and its lifespan is extremely long. Proxima Centauri has a lifespan of about 3 to 4 trillion years, and it is only 4.8 billion years old now. Isn't it in its infancy compared to its lifespan?

Research has found that in the early days of red dwarfs, the surface activity is extremely intense and huge flares often erupt. Proxima Centauri is only 7 million kilometers away from the main star. The high-energy X-rays and ultraviolet radiation emitted by the flares will destroy everything on the sun-facing surface of Proxima Centauri b. Moreover, its orbital period is only 11 days, which is a very fast speed. Therefore, the storm on it is much larger than that on Earth. (The above picture shows the ratio of the sun as seen from Earth and Proxima Centauri as seen from Proxima Centauri b)

Therefore, even if life was born in the twilight zone of Proxima b, the destruction it would endure would be much more severe than that of the Earth.

Proxima c is more than 220 million kilometers away from Proxima Centauri. In such a dim and cold star system, at such a long distance, it is like an ice ball. The surface temperature is more than 200 degrees below zero Celsius, and it is also a gas planet. It is basically impossible to give birth to life.

Proxima b will not have the three suns scorching environment described in the novel "The Three-Body Problem"

In the novel "The Three-Body Problem", the suffering of the Trisolarians is even more severe than that described above on Proxima b. The three suns take turns to burn, and sometimes all three suns appear at the same time, and the flames burn everything on the ground. But the fact is that this will not happen on Proxima b, because although Proxima b is not far from Alpha Centauri A and Alpha Centauri B, only 0.22 light years away, it will not be burned by them.

Let's see how bright Alpha Centauri A is from Proxima b.

The conversion formula between absolute magnitude and apparent magnitude is: m=M-5log(d0/d), where m is the apparent magnitude, M is the absolute magnitude, d0 is 10 arc seconds (about 32.6 light years), and d is the actual distance of the celestial body.

The absolute magnitude of Alpha Centauri A is 4.45. We put it into the formula and get the value of -6.4 when viewed from Proxima b, which is 0.22 light years away. The brightness of Alpha Centauri A is even weaker than that of Proxima Centauri. The brightness of the moon when viewed from Earth is -12.7. The brightest star in the night sky is the planet Venus, which is -4.7 at its brightest.

Therefore, the star A we see is only slightly brighter than Venus and nearly 400 times less bright than the moon. How can such brightness burn us? (See the picture below)

Therefore, if there are really Trisolarans on Proxima b, no matter how harsh their living environment is, they will not be scorched by three suns like in the novel "The Three-Body Problem". The story of the so-called Trisolaran fleet invading the earth is even more pure fiction. A technological civilization below level 2 cannot travel across the stars.

This is also what I said in the past. If aliens really come to Earth, they must be much more technologically advanced than human civilization to be able to do this. At this stage, it is nonsense to talk about humans resisting alien invasion.

That’s all I have to say. What do you think? Welcome to discuss. Thank you for reading.

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