What is the distance from Earth to the nearest star, Proxy Centauri?
- Consider - 3.87 light years * for 365 days * 86400 (number of seconds in a day) * 300,000 (speed of light km/s) = (approximately) like Vladimir Ustinov, and our Sun is only 150 million km
- Perhaps there are stars closer (the sun doesn’t count), but they are very small (a white dwarf, for example), but they have not yet been discovered. 4 light years is still very far away((((((
- The closest star from the Sun, Proxima Centauri. Its diameter is seven times less than that of the sun, and the same applies to its mass. Its luminosity is 0.17% of the luminosity of the Sun, or only 0.0056% in the spectrum visible to the human eye. This explains the fact that it cannot be seen with the naked eye, and the fact that it was discovered only in the 20th century. The distance from the Sun to this star is 4.22 light years. Which by cosmic standards is almost close. After all, even the gravity of our Sun extends to approximately half this distance! However, for humanity, this distance is truly enormous. Distances on planetary scales are measured in light years. How far will light travel in a vacuum in 365 days? This value is 9,640 billion kilometers. To understand distances, here are a few examples. The distance from the Earth to the Moon is 1.28 light seconds, and with modern technology the journey takes 3 days. Between the planets of our solar system, distances vary from 2.3 light minutes to 5.3 light hours. In other words, the longest journey will take just over 10 years on an unmanned spacecraft. Now let's consider how much time we need to fly to Proxima Centauri. Currently, the champion in speed is the unmanned spaceship Helios 2. Its speed is 253,000 km/h or 0.02334% of the speed of light. Having calculated, we find out that it will take us 18,000 years to get to the nearest star. At the current level of technology development, we can only ensure the operation of a spacecraft for 50 years.
- It's hard to imagine distances using numbers. If our sun is reduced to the size of a match head, then the distance to the nearest star will be approximately 1 kilometer
- Proxima Centauri is approximately 40,000,000,000,000 km away... 4.22 light years.. Alpha Centauri is 4.37 light years away. of the year…
- 4 light years (approximately 37,843,200,000,000 km)
- You are confusing something, dear colleague. The nearest star is the Sun. 8 minutes and a little with no light coming on :)
- To Proxima: 4.22 (+- 0.01) light years. Or 1.295 (+-0.004) parsec. Taken from here.
- to Proxima Centauri 4.2 light years is 41,734,219,479,449.6 km, if 1 light year is 9,460,528,447,488 km
- 4.5 light years (1 parsec?)
- There are stars in the Universe that are so far from us that we do not even have the opportunity to know their distance or determine their number. But how far is the nearest star from Earth?
The distance from the Earth to the Sun is 150,000,000 kilometers. Since light travels at 300,000 km/sec, it takes 8 minutes to travel from the Sun to the Earth.
The closest stars to us are Proxima Centauri and Alpha Centauri. The distance from them to the Earth is 270,000 times greater than the distance from the Sun to the Earth. That is, the distance from us to these stars is 270,000 times more than 150,000,000 kilometers! Their light takes 4.5 years to reach Earth.
The distance to the stars is so great that it was necessary to develop a unit for measuring this distance. It's called a light year. This is the distance that light travels in one year. This is approximately 10 trillion kilometers (10,000,000,000,000 km). The distance to the nearest star exceeds this distance by 4.5 times.
Of all the stars in the sky, only 6000 can be seen without a telescope, with the naked eye. Not all of these stars are visible from the UK.
In fact, looking up at the sky and observing the stars, there are a little over a thousand of them. And with a powerful telescope you can detect many, many times more.
Alpha Centauri is the target of spaceship flights in many works belonging to the science fiction genre. This closest star to us belongs to a celestial design embodying the legendary centaur Chiron, according to Greek mythology, who was the teacher of Hercules and Achilles.
Modern researchers, like writers, tirelessly return in their thoughts to this star system, since it is not only the first candidate for a long-term space expedition, but also a possible owner of an inhabited planet.
Structure
The Alpha Centauri star system includes three space objects: two stars with the same name and designations A and B, and such stars are characterized by a close location of two components and a distant location of the third. Proxima is just the latter. The distance to Alpha Centauri with all its elements is approximately 4.3 There are currently no stars located closer to Earth. At the same time, the fastest flight is to Proxima: we are separated by only 4.22 light years.
Solar relatives
Alpha Centauri A and B differ from their companion not only in their distance from Earth. Unlike Proxima, they are in many ways similar to the Sun. Alpha Centauri A or Rigel Centaurus (translated as “leg of the Centaur”) is the brighter component of the pair. Toliman A, as this star is also called, is a yellow dwarf. It is clearly visible from Earth, as it has a magnitude of zero. This parameter makes it the fourth brightest point in the night sky. The size of the object is almost the same as that of the sun.
The star Alpha Centauri B is inferior to our star in mass (about 0.9 of the corresponding parameter of the Sun). It is a first magnitude object, and its luminosity level is approximately half that of the main star of our piece of the Galaxy. The distance between the two neighboring companions is 23 astronomical units, meaning they are 23 times farther apart than the Earth is from the Sun. Toliman A and Toliman B rotate together around the same center of mass with a period of 80 years.
Recent discovery
Scientists, as already mentioned, have high hopes for discovering life in the vicinity of the star Alpha Centauri. The planets supposedly existing here may resemble Earth in the same way that the components of the system themselves resemble our star. Until recently, however, no such cosmic bodies were discovered near the star. The distance does not allow direct observation of the planets. Obtaining evidence of the existence of an earth-like object became possible only with the improvement of technology.
Using the radial velocity method, scientists were able to detect very small vibrations of Toliman B, which arise under the influence of the gravitational forces of the planet orbiting around it. Thus, evidence was obtained of the existence of at least one such object in the system. The vibrations caused by the planet appear as it moves 51 cm per second forward and then backward. Under Earth conditions, such a movement of even the largest body would be very noticeable. However, at a distance of 4.3 light years, detecting such a wobble seems impossible. Nevertheless, it was registered.
Sister of the Earth
The discovered planet orbits Alpha Centauri B in 3.2 days. It is located very close to the star: the orbital radius is ten times smaller than the corresponding parameter characteristic of Mercury. The mass of this space object is close to that of Earth and is approximately 1.1 times the mass of the Blue Planet. This is where the similarity ends: the close location, according to scientists, suggests that the emergence of life on the planet is impossible. The energy of the luminary reaching its surface heats it up too much.
Nearest
The third component that makes the entire constellation famous is Alpha Centauri C or Proxima Centauri. The name of the cosmic body translated means “nearest”. Proxima stands at a distance of 13,000 light years from its companions. This object is the eleventh red dwarf, small (about 7 times smaller than the Sun) and very dim. It is impossible to see it with the naked eye. Proxima is characterized by a “restless” state: the star is capable of doubling its brightness in a few minutes. The reason for this “behavior” is in the internal processes occurring in the bowels of the dwarf.
Dual position
Proxima has long been thought to be the third member of the Alpha Centauri system, orbiting the pair A and B every 500 years or so. However, in Lately The opinion is gaining strength that the red dwarf has nothing to do with them, and the interaction of the three cosmic bodies is a temporary phenomenon.
The reason for doubt was the data that said that the close-knit pair of stars does not have sufficient gravity to hold Proxima as well. The information obtained in the early 90s of the last century required additional confirmation for a long time. Recent observations and calculations by scientists have not given a clear answer. According to assumptions, Proxima may still be part of a triple system and move around a common gravitational center. In this case, its orbit should resemble an elongated oval, with the most distant point from the center being the one at which the star is observed now.
Projects
Be that as it may, it is to Proxima that it is planned to fly first when this becomes possible. The journey to Alpha Centauri, with the current level of development of space technology, can last more than 1000 years. Such a time period is simply unthinkable, which is why scientists are actively searching for options to reduce it.
A group of NASA researchers led by Harold White is developing Project Speed, which should result in a new engine. Its peculiarity will be the ability to overcome the speed of light, due to which the flight from Earth to the nearest star will take only two weeks. Such a miracle of technology will be a real masterpiece of the united work of theoretical physicists and experimentalists. For now, however, a ship that overcomes the speed of light is a thing of the future. According to Mark Millis, who once worked at NASA, such technologies, given the current rate of progress, will become a reality no earlier than in two hundred years. Reducing the period is possible only if a discovery is made that can radically change existing ideas about space flight.
For now, Proxima Centauri and its companions remain an ambitious goal, unattainable in the near future. The technology, however, is constantly being improved, and new information about the characteristics of the star system is clear evidence of this. Already today, scientists can do many things that they could not even dream of 40-50 years ago.
> > How long will it take to travel to the nearest star?
Find out, how long to fly to the nearest star: the closest star to Earth after the Sun, distance to Proxima Centauri, description of launches, new technologies.
Modern humanity spends efforts on mastering its native solar system. But can we go on reconnaissance to a neighboring star? And how many How long will it take to travel to the nearest star?? This can be answered very simply, or you can go deeper into the realm of science fiction.
Speaking from the perspective of today's technology, real numbers will scare off enthusiasts and dreamers. Let's not forget that the distances in space are incredibly vast and our resources are still limited.
The closest star to planet Earth is . This is the middle representative of the main sequence. But there are many neighbors concentrated around us, so now it’s possible to create a whole map of routes. But how long does it take to get there?
Which star is the closest
The closest star to Earth is Proxima Centauri, so for now you should base your calculations on its characteristics. It is part of the triple system Alpha Centauri and is distant from us at a distance of 4.24 light years. It is an isolated red dwarf located 0.13 light years from the binary star.
As soon as the topic of interstellar travel comes up, everyone immediately thinks about warp speed and jumping into wormholes. But all of them are either unattainable or absolutely impossible. Unfortunately, any long-distance mission will take more than one generation. Let's start the analysis with the slowest methods.
How long will it take to travel to the nearest star today?
It is easy to make calculations based on existing equipment and the limits of our system. For example, the New Horizons mission used 16 engines operating on hydrazine monopropellant. It took 8 hours 35 minutes to get to. But the SMART-1 mission was based on ion engines and took 13 months and two weeks to reach the earth’s satellite.
This means we have several vehicle options. In addition, it can be used as a giant gravitational slingshot. But if we plan to travel that far, we need to check all possible options.
Now we are talking not only about existing technologies, but also about those that in theory can be created. Some of them have already been tested on missions, while others are only in the form of drawings.
Ionic strength
This is the slowest method, but economical. Just a few decades ago, the ion engine was considered fantastic. But now it is used in many devices. For example, the SMART-1 mission reached the Moon with its help. In this case, the option with solar panels was used. Thus, he spent only 82 kg of xenon fuel. Here we win in efficiency, but definitely not in speed.
For the first time, the ion engine was used for Deep Space 1, flying to (1998). The device used the same type of engine as SMART-1, using only 81.5 kg of propellant. Over the course of 20 months of travel, he managed to accelerate to 56,000 km/h.
The ion type is considered much more economical than rocket technology because the thrust per unit mass of explosive is much higher. But it takes a lot of time to speed up. If they were planned to be used to travel from Earth to Proxima Centauri, a lot of rocket fuel would be needed. Although you can take previous indicators as a basis. So, if the device moves at a speed of 56,000 km/h, then it will cover a distance of 4.24 light years in 2,700 human generations. So it is unlikely to be used for a manned flight mission.
Of course, if you fill it with a huge amount of fuel, you can increase the speed. But the arrival time will still take a standard human life.
Help from gravity
This is a popular method as it allows you to use orbit and planetary gravity to change the route and speed. It is often used to travel to gas giants to increase speed. Mariner 10 tried this for the first time. He relied on the gravity of Venus to reach (February 1974). In the 1980s, Voyager 1 used the moons of Saturn and Jupiter to accelerate to 60,000 km/h and enter interstellar space.
But the record holder for the speed achieved using gravity was the Helios-2 mission, which set off to study the interplanetary medium in 1976.
Due to the high eccentricity of the 190-day orbit, the device was able to accelerate to 240,000 km/h. For this purpose, exclusively solar gravity was used.
Well, if we send Voyager 1 at 60,000 km/h, we'll have to wait 76,000 years. For Helios 2, this would have taken 19,000 years. It's faster, but not fast enough.
Electromagnetic drive
There is another way - radio frequency resonant motor (EmDrive), proposed by Roger Shavir in 2001. It is based on the fact that electromagnetic microwave resonators can convert electrical energy into thrust.
While conventional electromagnetic motors are designed to move a specific type of mass, this one does not use reaction mass and does not produce directed radiation. This type has been met with a huge amount of skepticism because it violates the law of conservation of momentum: a system of momentum within a system remains constant and changes only under the influence of force.
But recent experiments are slowly winning over supporters. In April 2015, researchers announced that they had successfully tested the disk in a vacuum (which means it can function in space). In July they had already built their version of the engine and discovered noticeable thrust.
In 2010, Huang Yang began a series of articles. She completed the final work in 2012, where she reported higher input power (2.5 kW) and tested thrust conditions (720 mN). In 2014, she also added some details about the use of internal temperature changes that confirmed the system's functionality.
According to calculations, a device with such an engine can fly to Pluto in 18 months. These are important results, because they represent 1/6 of the time that New Horizons spent. Sounds good, but even so, traveling to Proxima Centauri would take 13,000 years. Moreover, we still do not have 100% confidence in its effectiveness, so there is no point in starting development.
Nuclear thermal and electrical equipment
NASA has been researching nuclear propulsion for decades now. Reactors use uranium or deuterium to heat liquid hydrogen, transforming it into ionized hydrogen gas (plasma). It is then sent through the rocket nozzle to generate thrust.
A nuclear rocket power plant houses the same original reactor, which transforms heat and energy into electrical energy. In both cases, the rocket relies on nuclear fission or fusion to generate propulsion.
When compared with chemical engines, we get a number of advantages. Let's start with unlimited energy density. In addition, higher traction is guaranteed. This would reduce fuel consumption, which would reduce launch mass and mission costs.
So far there has not been a single launched nuclear thermal engine. But there are many concepts. They range from traditional solid designs to those based on a liquid or gas core. Despite all these advantages, the most complex concept achieves a maximum specific impulse of 5000 seconds. If you use such an engine to travel to when the planet is 55,000,000 km away (the “opposition” position), it will take 90 days.
But if we send it to Proxima Centauri, it will take centuries to accelerate to reach the speed of light. After that, it would take several decades to travel and centuries more to slow down. In general, the period is reduced to a thousand years. Great for interplanetary travel, but still not good for interstellar travel.
In theory
You probably already realized that modern technologies quite slow to cover such long distances. If we want to accomplish this in one generation, then we need to come up with something breakthrough. And if wormholes are still gathering dust on the pages of science fiction books, then we have several real ideas.
Nuclear impulse movement
Stanislav Ulam was involved in this idea back in 1946. The project started in 1958 and continued until 1963 under the name Orion.
Orion planned to use the power of impulsive nuclear explosions to create a strong shock with a high specific impulse. That is, we have a large spaceship with a huge supply of thermonuclear warheads. During drop, we use a detonation wave on the rear platform ("pusher"). After each explosion, the pusher pad absorbs the force and converts the thrust into impulse.
Naturally, in modern world The method is devoid of grace, but it guarantees the necessary impulse. By preliminary estimates, in this case it is possible to achieve 5% of the speed of light (5.4 x 10 7 km/h). But the design suffers from shortcomings. Let's start with the fact that such a ship would be very expensive, and it would weigh 400,000-4000,000 tons. Moreover, ¾ of the weight is represented by nuclear bombs (each of them reaches 1 metric ton).
The total cost of the launch would have risen at that time to 367 billion dollars (today - 2.5 trillion dollars). There is also the problem of the radiation and nuclear waste generated. It is believed that it was because of this that the project was stopped in 1963.
Nuclear Fusion
Here thermonuclear reactions are used, due to which thrust is created. Energy is produced when deuterium/helium-3 pellets are ignited in the reaction compartment through inertial confinement using electron beams. Such a reactor would detonate 250 pellets per second, creating a high-energy plasma.
This development saves fuel and creates a special boost. The achievable speed is 10,600 km (much faster than standard rockets). Recently, more and more people are interested in this technology.
In 1973-1978. The British Interplanetary Society created a feasibility study, Project Daedalus. It was based on current knowledge of fusion technology and the availability of a two-stage unmanned probe that could reach Barnard's star (5.9 light years) in a single lifetime.
The first stage will operate for 2.05 years and will accelerate the ship to 7.1% of the speed of light. Then it will be reset and the engine will start, increasing the speed to 12% in 1.8 years. After this, the second stage engine will stop and the ship will travel for 46 years.
In general, the ship will reach the star in 50 years. If you send it to Proxima Centauri, the time will be reduced to 36 years. But this technology also faced obstacles. Let's start with the fact that helium-3 will have to be mined on the Moon. And the reaction that powers the spacecraft requires that the energy released exceeds the energy used to launch it. And although testing went well, we still don't have required type energy that could power an interstellar spacecraft.
Well, let's not forget about money. A single launch of a 30-megaton rocket costs NASA $5 billion. So the Daedalus project would weigh 60,000 megatons. In addition, you will need the new kind thermonuclear reactor, which also does not fit into the budget.
Ramjet engine
This idea was proposed by Robert Bussard in 1960. This can be considered an improved form of nuclear fusion. It uses magnetic fields to compress hydrogen fuel until fusion is activated. But here a huge electromagnetic funnel is created, which “rips out” hydrogen from the interstellar medium and dumps it into the reactor as fuel.
The ship will pick up speed and cause the compressed magnetic field to achieve the process thermonuclear fusion. It will then redirect the energy in the form of exhaust gases through the engine injector and accelerate the movement. Without using other fuel, you can reach 4% of the speed of light and travel to anywhere in the galaxy.
But this scheme has a huge number of shortcomings. The problem of resistance immediately arises. The ship needs to increase speed to accumulate fuel. But it encounters huge amounts of hydrogen, so it can slow down, especially when it hits dense regions. In addition, it is very difficult to find deuterium and tritium in space. But this concept is often used in science fiction. The most popular example is Star Trek.
Laser sail
In order to save money, solar sails have been used for a very long time to move vehicles around the solar system. They are light and cheap, and do not require fuel. The sail uses radiation pressure from the stars.
But to use such a design for interstellar travel, it must be controlled by focused energy beams (lasers and microwaves). This is the only way to accelerate it to a point close to the speed of light. This concept was developed by Robert Ford in 1984.
The bottom line is that all the benefits of a solar sail remain. And although the laser will take time to accelerate, the limit is only the speed of light. A 2000 study showed that a laser sail could accelerate to half the speed of light in less than 10 years. If the size of the sail is 320 km, then it will reach its destination in 12 years. And if you increase it to 954 km, then in 9 years.
But its production requires the use of advanced composites to avoid melting. Don't forget that it must reach huge sizes, so the price will be high. In addition, you will have to spend money on creating a powerful laser that could provide control at such high speeds. The laser consumes a constant current of 17,000 terawatts. So you understand, this is the amount of energy that the entire planet consumes in one day.
Antimatter
This is a material represented by antiparticles that reach the same mass as ordinary ones, but have the opposite charge. Such a mechanism would use the interaction between matter and antimatter to generate energy and create thrust.
In general, such an engine uses hydrogen and antihydrogen particles. Moreover, in such a reaction the same amount of energy is released as in a thermonuclear bomb, as well as a wave of subatomic particles moving at 1/3 the speed of light.
The advantage of this technology is that most of the mass is converted into energy, which will create higher energy density and specific impulse. As a result, we will get the fastest and most economical spacecraft. If a conventional rocket uses tons of chemical fuel, then an engine with antimatter spends only a few milligrams for the same actions. This technology would be great for a trip to Mars, but it can't be applied to another star because the amount of fuel increases exponentially (along with the costs).
A two-stage antimatter rocket would require 900,000 tons of fuel for a 40-year flight. The difficulty is that to extract 1 gram of antimatter will require 25 million billion kilowatt-hours of energy and more than a trillion dollars. Right now we only have 20 nanograms. But such a ship is capable of accelerating to half the speed of light and flying to the star Proxima Centauri in the constellation Centaurus in 8 years. But it weighs 400 Mt and consumes 170 tons of antimatter.
As a solution to the problem, they proposed the development of a “Vacuum Antimaterial Rocket Interstellar Research System.” This could use large lasers that create antimatter particles when fired into empty space.
The idea is also based on using fuel from space. But again the moment of high cost arises. In addition, humanity simply cannot create such an amount of antimatter. There is also a radiation risk, as matter-antimatter annihilation can create bursts of high-energy gamma rays. It will be necessary not only to protect the crew with special screens, but also to equip the engines. Therefore, the product is inferior in practicality.
Alcubierre Bubble
In 1994, it was proposed by the Mexican physicist Miguel Alcubierre. He wanted to create a tool that would not violate the special theory of relativity. It suggests stretching the fabric of spacetime in a wave. Theoretically, this will cause the distance in front of the object to decrease and the distance behind it to expand.
A ship caught inside a wave will be able to move beyond relativistic speeds. The ship itself will not move in the “warp bubble”, so the rules of space-time do not apply.
If we talk about speed, then this is “faster than light,” but in the sense that the ship will reach its destination faster than a beam of light leaving the bubble. Calculations show that he will arrive at his destination in 4 years. If we think about it in theory, this is the fastest method.
But this scheme does not take into account quantum mechanics and is technically annulled by the Theory of Everything. Calculations of the amount of energy required also showed that extremely enormous power would be required. And we haven’t touched on security yet.
However, in 2012 there was talk that this method was being tested. Scientists claimed to have built an interferometer that could detect distortions in space. In 2013, the Jet Propulsion Laboratory conducted an experiment in vacuum conditions. In conclusion, the results seemed inconclusive. If you look deeper, you can understand that this scheme violates one or more fundamental laws of nature.
What follows from this? If you were hoping to make a round trip to the star, the odds are incredibly low. But if humanity decided to build a space ark and send people on a century-long journey, then anything is possible. Of course, this is just talk for now. But scientists would be more active in such technologies if our planet or system were in real danger. Then a trip to another star would be a matter of survival.
For now, we can only surf and explore the expanses of our native system, hoping that in the future a new method will appear that will make it possible to implement interstellar transits.
Proxima Centauri is the star closest to Earth. It got its name from the Latin word proxima, which means “nearest.” The distance from it to the Sun is 4.22 light years. However, despite the fact that the star is closer to us than the Sun, it can only be seen through a telescope. It is so small that nothing was known about its existence until 1915. The discoverer of the star was Robert Innes, an astronomer from Scotland.
Alpha Centauri
Proxima is part of the system. In addition to it, it also includes two more stars: Alpha Centauri A and Alpha Centauri B. They are much brighter and more visible than Proxima. Thus, star A, the brightest in this constellation, is located at a distance of 4.33 light years from the Sun. It is called Rigel Centauri, which translates as “Leg of the Centaur.” This star is somewhat reminiscent of our Sun. Probably because of its brightness. Unlike Proxima Centauri, it has been known since ancient times, as it is very visible in the night sky.
Alpha Centauri B is also not inferior to its “sister” in brightness. Together they are a tight binary system. Proxima Centauri is quite far from them. Between the stars there is a distance of thirteen thousand astronomical units (this is four hundred times further than from the Sun to the planet Neptune!).
All stars in the Centauri system orbit around their common center of mass. Only Proxima moves very slowly: its orbital period takes millions of years. Therefore, this star will remain closest to Earth for a very long time.
Very small
The star Proxima Centauri is not only the closest star in the constellation to us, but is also the smallest. Its mass is so tiny that it is barely enough to support the processes of formation of helium from hydrogen necessary for existence. The star glows very dimly. Proxima is much lighter than the Sun, about seven times. And the temperature on its surface is much lower: “only” three thousand degrees. Proxima is one hundred and fifty times brighter than the Sun.
Red dwarfs
The small star Proxima belongs to the spectral class M with very low luminosity. Another widely known name for celestial bodies of this class is red dwarfs. Stars with such low mass are interesting objects. Their internal structure is somewhat similar to the structure of giant planets such as Jupiter. The substance of red dwarfs is in an exotic state. In addition, there are suggestions that planets located near such stars may be suitable for life.
Red dwarfs live a very long time, much longer than any other stars. They evolve very slowly. Any nuclear reactions inside them begin to occur only several billion years after their origin. The lifespan of a red dwarf is longer than the lifetime of the entire Universe! So, in the distant, distant future, when more than one star like the Sun goes out, the red dwarf Proxima Centauri will still shine dimly in the darkness of space.
In general, red dwarfs are the most common stars in our galaxy. More than 80% of all stellar bodies are made up of them. And here’s the paradox: they are completely invisible! You won't notice any of them with the naked eye.
Measurement
Until now, it was simply not possible to accurately measure the sizes of small stars such as red dwarfs due to their weak luminosity. But today this problem solved using a special VLT interferometer (VLT is an abbreviation for Very Large Telescope). This device operates on the basis of two large 8.2-meter VLT telescopes located at the Paranal Astronomical Observatory (ESO). These two huge telescopes, 102.4 meters apart, allow measurements with such precision that other devices simply cannot do. This is how astronomers at the Geneva Observatory for the first time obtained the exact dimensions of such a small star.
Changeable Centauri
In terms of its size, Proxima Centauri borders between a real star, a planet and And yet it is a star. Its mass and diameter are one-seventh of its mass, and also respectively. The star is one hundred and fifty times more massive than the planet Jupiter, but weighs one and a half times less. If Proxima Centauri weighed even less, then it simply could not become a star: there would not be enough hydrogen in its depths to emit light. In this case, it would be an ordinary brown dwarf (i.e., dead), and not a real star.
Proxima itself is a very dim celestial body. In its normal state, its luminosity reaches no more than 11m. It appears bright only in photographs taken by huge telescopes, such as Hubble. However, sometimes the brightness of a star increases sharply and significantly. Scientists explain this fact by the fact that Proxima Centauri belongs to the class of so-called changeable, or flare-up, stars. This is caused by strong flares on its surface, which are the results of violent convection processes. They are somewhat similar to those that occur on the surface of the Sun, only much stronger, which even leads to a change in the brightness of the star.
Still just a child
These violent processes and outbreaks indicate that the nuclear reactions occurring in the depths of Proxima Centauri have not yet stabilized. Scientists' conclusions: this is still a very young star by cosmic standards. Although its age is quite comparable to the age of our Sun. But Proxima is a red dwarf, so they can't even be compared. After all, like other “red brothers”, it will burn its nuclear fuel very slowly and economically, and therefore will shine for a very, very long time - approximately three hundred times longer than our entire Universe! What can we say about the Sun...
Many science fiction writers believe that Proxima Centauri is the most suitable star for space exploration and adventure. Some believe that there are planets hidden in her Universe where other civilizations can be found. Maybe it is so, but the distance from Earth to Proxima Centauri is more than four light years. So, even though it is the closest, it is still quite far away.
Since ancient times, man has turned his gaze to the sky, where he saw thousands of stars. They fascinated him and made him think. Over the centuries, knowledge about them accumulated and systematized. And when it became clear that the stars are not just luminous points, but real cosmic objects of enormous size, a person had a dream - to fly to them. But first we had to determine how far away they were.
The closest star to Earth
Using telescopes and mathematical formulas, scientists were able to calculate the distances to our (excluding solar system objects) cosmic neighbors. So, which star is closest to Earth? It turned out to be little Proxima Centauri. It is part of a triple system located at a distance of approximately just over four light years from the Solar System (it is worth noting that astronomers more often use another unit of measurement - the parsec). She was named proxima, which means “nearest” in Latin. For the Universe, this distance seems insignificant, but with the current level of space shipbuilding, it will take more than one generation of people to reach it.
Proxima Centauri
In the sky this star can only be seen through a telescope. It shines about one hundred and fifty times weaker than the Sun. It is also significantly smaller in size than the latter, and its surface temperature is two times lower. Astronomers consider this star and the existence of planets around it to be unlikely. And therefore there is no point in flying there. Although the triple system itself deserves attention - such objects are not very common in the Universe. The stars in them revolve around each other in bizarre orbits, and sometimes they “devour” their neighbor.
Deep space
Let's say a few words about the most distant object discovered so far in the Universe. Of those visible without the use of special optical devices, this is, without a doubt, the Andromeda Nebula. Its brightness is approximately a quarter magnitude. And the closest star to Earth in this galaxy is located from us, according to astronomers, at a distance of two million light years. Mind-blowing magnitude! After all, we see it as it was two million years ago - that’s how easy it is to look into the past! But let's return to our “neighbors”. The closest galaxy to us is a dwarf galaxy, which can be observed in the constellation Sagittarius. She is so close to us that she practically absorbs her! True, it will still take eighty thousand light years to fly to it. These are the distances in space! The Magellanic Cloud is not worth talking about. This satellite of the Milky Way is almost 170 million light years behind us.
The closest stars to Earth
There are fifty-one relatively close to the Sun. But we will list only eight. So, meet:
- Proxima Centauri, already mentioned above. Distance - four light years, class M5.5 (red or brown dwarf).
- The stars Alpha Centauri A and B. They are 4.3 light years away from us. Objects of class D2 and K1 respectively. Alpha Centauri is also the closest star to Earth, similar in temperature to our Sun.
- Barnard's Star - it is also called "Flying" because it moves at a high speed (compared to other space objects). Located at a distance of 6 light years from the Sun. Object class M3.8. In the sky it can be found in the constellation Ophiuchus.
- Wolf 359 is located 7.7 light years away. 16th magnitude object in the constellation Draco. Class M5.8.
- Lalande 1185 is 8.2 light years away from our system. Located in Object class M2.1. Magnitude - 10.
- Tau Ceti is located 8.4 light years away. M5,6 class star.
- The Sirius A and B system is eight and a half light years away. Stars class A1 and DA.
- Ross 154 in the constellation Sagittarius. Located at a distance of 9.4 light years from the Sun. M class star 3.6.
Only space objects located within a radius of ten light years from us are mentioned here.
Sun
However, looking at the sky, we forget that the closest star to Earth is still the Sun. This is the center of our system. Without it, life on Earth would have been impossible, and our planet was formed along with this star. That’s why it deserves special attention. A little about her. Like all stars, the Sun is composed primarily of hydrogen and helium. Moreover, the first one constantly turns into the last one. As a result, heavier elements are also formed. And the older the star, the more they accumulate.
In terms of age, the closest star to Earth is no longer young, it is about five billion years old. is ~2.10 33 g, diameter - 1,392,000 kilometers. The temperature on the surface reaches 6000 K. In the middle of the star it rises. The atmosphere of the Sun consists of three parts: the corona, the chromosphere and the photosphere.
Solar activity significantly affects life on Earth. It is argued that climate, weather and the state of the biosphere depend on it. It is known about the eleven-year periodicity of solar activity.
