Proxima Centauri.

Here's a classic backfill question. Ask your friends Which one is closest to us?" and then watch them list nearest stars. Maybe Sirius? Alpha something there? Betelgeuse? The answer is obvious - it is; a massive ball of plasma located about 150 million kilometers from Earth. Let's clarify the question. Which star is closest to the Sun?

nearest star

You have probably heard that - the third brightest star in the sky at a distance of only 4.37 light years from. But Alpha Centauri not a single star, it is a system of three stars. First, a binary star (binary star) with a common center of gravity and an orbital period of 80 years. Alpha Centauri A is only slightly more massive and brighter than the Sun, while Alpha Centauri B is slightly less massive than the Sun. There is also a third component in this system, a dim red dwarf Proxima Centauri (Proxima Centauri).

Proxima Centauri- That's what it is closest star to our sun, located at a distance of only 4.24 light years.

Proxima Centauri.

Multiple star system Alpha Centauri located in the constellation Centaurus, which is only visible in the southern hemisphere. Unfortunately, even if you see this system, you will not be able to see Proxima Centauri. This star is so dim that you need a powerful enough telescope to see it.

Let's find out the scale of how far Proxima Centauri from U.S. Think about. moves at a speed of almost 60,000 km / h, the fastest in. He overcame this path in 2015 for 9 years. Traveling so fast to get to Proxima Centauri, New Horizons will need 78,000 light years.

Proxima Centauri is the nearest star over 32,000 light years, and it will hold this record for another 33,000 years. It will make its closest approach to the Sun in about 26,700 years, when the distance from this star to the Earth will be only 3.11 light years. In 33,000 years, the nearest star will be Ross 248.

What about the northern hemisphere?

For those of us who live in the northern hemisphere, the nearest visible star is Barnard's Star, another red dwarf in the constellation Ophiuchus (Ophiuchus). Unfortunately, like Proxima Centauri, Barnard's Star is too dim to see with the naked eye.

Barnard's Star.

nearest star, which you can see with the naked eye in the northern hemisphere is Sirius (Alpha Canis Major). Sirius is twice the size and mass of the Sun and is the brightest star in the sky. Located 8.6 light-years away in the constellation Canis Major (Canis Major), it is the most famous star chasing Orion in the night sky during the winter.

How did astronomers measure the distance to stars?

They use a method called . Let's do a little experiment. Hold one arm outstretched at length and place your finger so that some distant object is nearby. Now alternately open and close each eye. Notice how your finger seems to jump back and forth when you look with different eyes. This is the parallax method.

Parallax.

To measure the distance to the stars, you can measure the angle to the star with respect to when the Earth is on one side of the orbit, say in the summer, then 6 months later when the Earth moves to the opposite side of the orbit, and then measure the angle to the star compared to which some distant object. If the star is close to us, this angle can be measured and the distance calculated.

You can really measure the distance in this way to nearby stars, but this method only works up to 100,000 light years.

20 nearest stars

Here is a list of the 20 nearest star systems and their distances in light years. Some of them have several stars, but they are part of the same system.

Star	Distance, St. years
Alpha Centauri	4,2
Barnard's Star	5,9
Wolf 359 (Wolf 359; CN Lion)	7,8
Lalande 21185 (Lalande 21185)	8,3
Sirius	8,6
Leuthen 726-8 (Luyten 726-8)	8,7
Ross 154 (Ross 154)	9,7
Ross 248 (Ross 248	10,3
Epsilon Eridani	10,5
Lacaille 9352 (Lacaille 9352)	10,7
Ross 128 (Ross 128)	10,9
EZ Aquarii (EZ Aquarii)	11,3
Procyon (Procyon)	11,4
61 Cygni	11,4
Struve 2398 (Struve 2398)	11,5
Groombridge 34 (Groombridge 34)	11,6
Epsilon Indi	11,8
DX Cancri	11,8
Tau Ceti	11,9
GJ 106	11,9

According to NASA, there are 45 stars within a radius of 17 light years from the Sun. There are over 200 billion stars in the universe. Some of them are so dim that they are almost impossible to detect. Perhaps with new technologies, scientists will find stars even closer to us.

The title of the article you read "Closest Star to the Sun".

> > 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 the development of the native solar system. But will we be able to go on exploration to a neighboring star? And how much time to travel to the nearest star? This can be answered very simply or delved into the realm of science fiction.

Speaking from the position of today's technologies, the real numbers will scare off enthusiasts and dreamers. Let's not forget that space is incredibly vast and our resources are still limited.

The closest star to the planet Earth is. This is the middle representative of the main sequence. But there are a lot of neighbors around us, so we can already create a whole route map. But how long does it take to get there?

Which star is the closest

The closest star to the Earth is Proxima Centauri, so for now, you should base your calculations on the basis of its characteristics. It is part of the Alpha Centauri triple system 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 pops up, everyone immediately thinks about the speed of deformation and jumping into wormholes. But all of them are either unattainable or absolutely impossible. Unfortunately, any long-range mission will take more than one generation. Let's start with the slowest methods.

How long will it take to travel to the nearest star today

It is easy to make calculations based on the existing technique and the limits of our system. For example, the New Horizons mission used 16 hydrazine monopropellant engines. It took 8 hours and 35 minutes to get to . But the SMART-1 mission was based on ion engines and traveled to the earth's satellite for 13 months and two weeks.

So we have several vehicle options. In addition, it can be used or as a giant gravitational slingshot. But if we plan to go this 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 have only been drawn up in the form of drawings.

Ionic strength

This is the slowest way, but economical. A few decades ago, the ion engine was considered fantastic. But now it is used in many devices. For example, the SMART-1 mission got to 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 terms of efficiency, but definitely not in terms of speed.

For the first time, an ion engine was used for Deep Space 1, flying to (1998). The device used the same type of engine as the SMART-1, using only 81.5 kg of propellant. For 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 the explosive is much higher. But it takes a long time to accelerate. If they were planned to be used to travel from Earth to Proxima Centauri, then a lot of rocket fuel would be needed. Although you can take the 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 route and speed. It is often used to travel to the 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 80s, Voyager 1 used the moons of Saturn and Jupiter to accelerate to 60,000 km/h and go into interstellar space.

But the record holder for the speed obtained using gravity was the Helios-2 mission, which went to study the interplanetary medium in 1976.

Due to the large eccentricity of the 190-day orbit, the device was able to accelerate to 240,000 km / h. For this, only 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, it would have taken 19,000 years. It's faster, but not 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 transform electrical energy into traction.

While conventional electromagnetic motors are designed to move a particular type of mass, this one does not use a reaction mass and does not produce directional radiation. This view has been met with a great deal of skepticism because it violates the law of conservation of momentum: a system of momentum within a system remains constant and only changes under the action of a force.

But recent experiments are slowly poaching supporters. In April 2015, researchers announced that they had successfully tested the disk in a vacuum (meaning it could function in space). In July, they had already built their own version of the engine and showed noticeable thrust.

In 2010, Huang Yang took over a series of articles. She finished her final work in 2012, where she reported higher input power (2.5kW) and tested thrust conditions (720mN). In 2014, she also added some details about the use of internal temperature changes, which confirmed the operability of the system.

If you believe the 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, it would take 13,000 years to travel to Proxima Centauri. 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's nozzle to form thrust.

A nuclear-rocket power plant contains the same original reactor that transforms heat and energy into electrical energy. In both cases, the rocket relies on nuclear fission or fusion to generate propulsion systems.

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 the level of fuel consumption, and therefore, would reduce the mass of the launch and the cost of the missions.

So far, there has not been a single launched nuclear-thermal engine. But there are many concepts. They range from traditional solid structures to those based on liquid or gaseous cores. Despite all these advantages, the most sophisticated concept achieves a maximum specific impulse of 5000 seconds. If you use a similar engine to travel to when the planet is 55,000,000 km away (the "opposition" position), then it will take 90 days.

But, if we send it to Proxima Centauri, then it will take centuries for acceleration to move to the speed of light. After that, it would take several decades to travel and another century 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 technology is rather slow to overcome such long distances. If we want to do this in one generation, then we need to come up with something breakthrough. And if wormholes are still gathering dust in the pages of science fiction books, then we have a few real ideas.

Nuclear impulse movement

This idea was developed by Stanislav Ulam 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 push with a high specific impulse. That is, we have a large spacecraft with a huge stock of thermonuclear warheads. During the drop, we use a detonation wave on the rear platform ("pusher"). After each explosion, the pusher pad absorbs the force and converts thrust into momentum.

Naturally, in the modern world, the method lacks elegance, but it guarantees the necessary impulse. According to preliminary estimates, in this case it is possible to reach 5% of the speed of light (5.4 x 10 7 km/h). But the design suffers from flaws. Let's start with the fact that such a ship would be very expensive, and it would weigh 400,000-4,000,000 tons. Moreover, ¾ of the weight is represented by nuclear bombs (each of them reaches 1 metric ton).

The total launch cost would have risen to $367 billion at the time ($2.5 trillion today). There is also a problem with the generated radiation and nuclear waste. 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 chamber via inertial confinement using electron beams. Such a reactor would detonate 250 pellets per second, creating a high-energy plasma.

In such a development, fuel is saved and a special momentum is created. Achievable speed - 10600 km (significantly faster than standard missiles). Recently, more and more people are interested in this technology.

In 1973-1978. The British Interplanetary Society has created a feasibility study - Project Daedalus. It relied 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 work for 2.05 years and will accelerate the ship to 7.1% of the speed of light. Then it will be dropped and the engine will start, increasing the speed to 12% in 1.8 years. After that, the engine of the second stage 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, then the time will be reduced to 36 years. But this technology, too, has encountered obstacles. Let's start with the fact that helium-3 will have to be mined on the moon. And the reaction that activates the movement of the spacecraft requires that the energy released exceed the energy used to launch. And while the testing went well, we still don't have the kind of power we need to power an interstellar spacecraft.

Well, let's not forget the money. A single launch of a 30 megaton rocket costs NASA $5 billion. So the Daedalus project would weigh 60,000 megatons. In addition, a new type of fusion reactor will be needed, which also does not fit into the budget.

ramjet engine

This idea was proposed by Robert Bussard in 1960. You can think of it as an improved form of nuclear fusion. It uses magnetic fields to compress hydrogen fuel until the fusion is activated. But here a huge electromagnetic funnel is created, which “pulls 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 reach the fusion process. After that, it will redirect the energy in the form of exhaust gases through the engine nozzle and accelerate the movement. Without the use of other fuel, you can reach 4% of the speed of light and go anywhere in the galaxy.

But this scheme has a huge bunch of shortcomings. The problem of resistance immediately arises. The ship needs to increase its speed in order to accumulate fuel. But it encounters a huge amount of hydrogen, so it can slow down, especially when it gets into 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, besides they do not require fuel. The sail uses the radiation pressure from the stars.

But in order to use such a structure for interstellar travel, it is necessary to control it with focused energy beams (lasers and microwaves). Only in this way can it be accelerated to a mark 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 are retained. 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 reach 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 for its production it is necessary to use advanced composites to avoid melting. Do not forget that it must reach a huge size, 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 direct current of 17,000 terawatts. For you to understand, this is the amount of energy that the entire planet consumes in one day.

antimatter

This is a material represented by antiparticles, which 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, particles of hydrogen and antihydrogen are involved in such an engine. 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 of the speed of light.

The advantage of this technology is that most of the mass is converted into energy, which will create a 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 antimatter engine spends only a few milligrams on the same actions. Such technology would be a great option for a trip to Mars, but it cannot be applied to another star, because the amount of fuel is growing exponentially (along with costs).

A two-stage antimatter rocket would require 900,000 tons of propellant for a 40-year flight. The difficulty is that to extract 1 gram of antimatter, 25 million billion kilowatt-hours of energy and more than a trillion dollars will be needed. Right now we only have 20 nanograms. But such a vessel 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 spends 170 tons of antimatter.

As a solution to the problem, they proposed the development of the “Vacuum of an anti-material rocket interstellar research system”. Here one could use large lasers that create antimatter particles when fired in empty space.

The idea is also based on the use of fuel from space. But again there is a moment of high cost. In addition, humanity simply cannot create such an amount of antimatter. There is also the risk of radiation, as matter-antimatter annihilation can create explosions 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 tool is inferior in practicality.

Bubble Alcubierre

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. He proposes stretching the fabric of space-time in a wave. Theoretically, this will lead to the fact that the distance in front of the object will be reduced, and behind it will expand.

A ship caught inside the wave will be able to move beyond relativistic speeds. The ship itself in the "warp bubble" will not move, 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 that has gone beyond the bubble. Calculations show that it will arrive at its destination in 4 years. If you think in theory, then this is the fastest method.

But this scheme does not take into account quantum mechanics and is technically nullified by the Theory of Everything. Calculations of the amount of energy required also showed that an extremely huge power would be required. And we haven't touched on security issues yet.

However, in 2012 there was talk that this method was being tested. The scientists claimed to have built an interferometer that could detect distortions in space. In 2013, an experiment was conducted at the Jet Propulsion Laboratory in a vacuum. In conclusion, the results were inconclusive. If you go deeper, you can understand that this scheme violates one or more of the fundamental laws of nature.

What follows from this? If you were hoping to make a round trip to a star, then the chances are incredibly low. But, if humanity decided to build a space ark and send people on an age-old journey, then everything 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.

So far, we can only plow 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.

With the help of telescopes of the European Southern Observatory (ESO), astronomers have managed to make another amazing discovery. This time they have found clear evidence of the existence of an exoplanet orbiting the closest star to Earth - Proxima Centauri. The world, called Proxima Centauri b (Proxima Centauri b), has long been sought by scientists all over the Earth. Now, thanks to his discovery, it has been established that the period of his revolution around his native star (year) is 11 Earth days, and the surface temperature of this exoplanet is suitable for the possibility of finding water in liquid form. By itself, this stone world is slightly larger than the Earth and, like the star, has become the closest to us of all such space objects. In addition, it is not just the closest exoplanet to Earth, it is also the closest world suitable for the existence of life.

Proxima Centauri is a red dwarf, and it is located at a distance of 4.25 light years from us. The star got its name for a reason - this is another confirmation of its proximity to the Earth, since proxima is translated from Latin as “nearest”. This star is located in the constellation of Centaurus, and its luminosity is so weak that it is completely impossible to see with the naked eye, and besides, it is quite close to the much brighter pair of stars α Centauri AB.

During the first half of 2016, Proxima Centauri was regularly studied with the HARPS spectrograph installed on the 3.6-meter telescope in Chile, as well as simultaneously with other telescopes from around the world. The star was studied as part of the Pale Red Dot campaign (a pale red dot or red speck), during which scientists from the University of London studied the oscillations of a star caused by the presence of an unidentified exoplanet in its orbit. The name of this program is a direct reference to the famous image of the Earth from the far reaches of the solar system. Then Carl Sagan called this picture (blue speck). Since Proxima Centauri is a red dwarf, the name of the program has been adjusted.

Since this topic of exoplanet search has generated widespread public interest, the progress of scientists in this work from mid-January to April 2016 was constantly publicly published on the program's own website and through social media. These reports were accompanied by numerous articles written by experts from all over the world.

“We received the first hints of the possibility of the existence of an exoplanet here, but our data then turned out to be inconclusive. Since then we have been working hard to improve our observations with the help of the European Observatory and other organizations. For example, the planning of this campaign took approximately two years,” Guillem Anglada-Escude, head of the research team.

Data from the Pale Red Dot campaign, combined with earlier observations from ESO's observatories and others, showed a clear signal of the exoplanet's presence. It has been very accurately established that from time to time Proxima Centauri approaches the Earth at a speed of 5 kilometers per hour, which is equal to the usual human speed, and then moves away at the same speed. This regular cycle of changing radial velocities repeats with a period of 11.2 days. Careful analysis of the resulting Doppler shifts indicated the presence of a planet here with a mass of at least 1.3 times the mass of the Earth at a distance of 7 million kilometers from Proxima Centauri, which is only 5 percent of the distance from Earth to the Sun. In general, such a detection has become technically possible only in the last 10 years. But, in fact, even signals with smaller amplitudes have been detected earlier. However, stars are not smooth balls of gas, and Proxima Centauri is a very active star. Therefore, accurate detection of Proxima Centauri b became possible only after obtaining a detailed description of how the star changes on time scales from minutes to decades, and monitoring its luminosity with light-measuring telescopes.

“We continued to check the data so that the received signal did not contradict what we found. This was done every day for another 60 days. After the first ten days, we had confidence, after 20 days we realized that our signal was in line with expectations, and after 30 days all the data categorically stated the discovery of the exoplanet Proxima Centauri b, so we began to prepare articles on this event.

Red dwarfs, such as Proxima Centauri, are active stars and have many tricks in their arsenal to be able to mimic the presence of an exoplanet in their orbits. To eliminate this error, the researchers monitored the change in the brightness of the star using the ASH2 telescope at the San Pedro de Atacami Observatory in Chile and the Las Cumbres Observatory network of telescopes. Information about radial velocities as the star's luminosity increased was excluded from the final analysis.

Despite the fact that Proxima Centauri b rotates much closer to its star than Mercury orbits the Sun, Proxima Centauri itself is much weaker than our star. As a result, the discovered exoplanet is located exactly in the region around the star that is suitable for the existence of life as we know it, and the estimated temperature of its surface allows the presence of water in liquid form. Despite such a moderate orbit, the conditions of existence on its surface can be very strongly influenced by ultraviolet radiation and X-ray flares from the star, which are much more intense than the effects that the Sun has on Earth.

The actual possibility of this kind of planet supporting liquid water and having life like Earth is a matter of intense but mostly theoretical debate. The main arguments that speak against the presence of life are related to the proximity of Proxima Centauri. For example, on Proxima Centauri b, such conditions can be created under which it always faces the star on one side, which is why there is eternal night on one half and eternal day on the other. The planet's atmosphere could also slowly evaporate or have more complex chemistry than Earth's due to strong ultraviolet and X-ray radiation, especially during the star's first billion years of life. However, so far not a single argument has been definitively proven, and it is unlikely that they will be eliminated without direct observational evidence and obtaining accurate characteristics of the planet's atmosphere.

Two separate papers were devoted to the habitability of Proxima Centauri b and its climate. It has been established that today the existence of liquid water on the planet cannot be ruled out, and in this case it can be present on the surface of the planet only in the sunniest regions, either in the hemisphere of the planet, always facing the star (synchronous rotation), or in the tropical zone (3: 2 resonant rotation). The rapid movement of Proxima Centauri b around the star, the strong radiation of Proxima Centauri and the history of the formation of the planet made the climate on it completely different from that on Earth, and it is unlikely that Proxima Centauri b has seasons at all.

One way or another, this discovery will be the beginning of large-scale further observations, both with current instruments and with the next generation of giant telescopes, such as the European Extremely Large Telescope (E-ELT). In the coming years, Proxima Centauri b will become a prime target for the search for life elsewhere in the universe. This is quite symbolic, since the Alpha Centauri system is also chosen as the target of humanity's first attempt to move to another star system. The Breakthrough Starshot project is a research and engineering project within the Breakthrough Initiatives program to develop a concept for a fleet of light sail spacecraft called the StarChip. This type of spacecraft would be able to travel to the Alpha Centauri star system, 4.37 light-years from Earth, at between 20 and 15 percent of the speed of light, which would take 20 to 30 years, respectively, and about 4 more years to notify the Earth of a successful arrival.

In conclusion, I would like to note that many accurate methods for searching for exoplanets are based on the analysis of its passage through the disk of a star and starlight through its atmosphere. At present, there is no evidence that Proxima Centauri b passes through the disk of the parent star, and the possibilities to see this event are currently negligible. However, scientists hope that in the future the efficiency of observational instruments will increase.

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 has been accumulated and systematized. And when it became clear that the stars are not just luminous points, but real space objects of enormous size, a person had a dream - to fly to them. But first it was necessary to determine how far they were.

closest star to earth

With the help of telescopes and mathematical formulas, scientists were able to calculate the distances to our (excluding objects in the solar system) space neighbors. So what is the closest star to Earth? It turned out to be a small Proxima Centauri. It is part of a triple system located at a distance of about four light-years from the solar system (it is worth noting that astronomers often use a different unit of measurement - the parsec). She was named proxima, which in Latin means "nearest". 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 weaker than the Sun about one hundred and fifty times. In size, it is also significantly inferior to the latter, and the temperature of its surface is half as much. Astronomers consider this star and the existence of planets around it is hardly possible. And therefore it makes no sense to fly there. Although the triple system in itself deserves attention, such objects are not very common in the Universe. The stars in them turn one around the other in bizarre orbits, and it happens that they “devour” a 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 roughly corresponds to a quarter magnitude. And the closest star to the Earth of this galaxy is from us, according to the calculations of astronomers, at a distance of two million light years. Astonishing value! After all, we see it as it was two million years ago - that's how easy it is to look into the past! But back to our "neighbors". The closest galaxy to us is a dwarf galaxy, which can be observed in the constellation Sagittarius. It is so close to us that it almost absorbs it! True, it will still take eighty thousand light years to fly to it. These are the distances in space! The Magellanic Cloud is out of the question. This satellite of the Milky Way is almost 170 million light-years behind us.

The closest stars to Earth

Fifty-one are relatively close to the Sun. But we will list only eight. So, get acquainted:

1. Proxima Centauri already mentioned above. Distance - four light years, class M5.5 (red or brown dwarf).
2. 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.
3. Barnard's Star - it is also called "Flying" because it moves at a high (compared to other space objects) speed. It is located at a distance of 6 light years from the Sun. Object of class M3,8. In the sky, it can be found in the constellation Ophiuchus.
4. Wolf 359 is located at a distance of 7.7 light years from us. An object of 16th magnitude in the constellation Draco. Class M5.8.
5. Lalande 1185 is 8.2 light years away from our system. Located in the object of class M2.1. Magnitude - 10.
6. Tau Ceti is located at a distance of 8.4 light years from us. Star class M5,6.
7. The Sirius A and B systems are eight and a half light years away. Stars class A1 and DA.
8. Ross 154 in the constellation Sagittarius. It is located at a distance of 9.4 light years from the Sun. Star class M 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 the Earth is still the Sun. This is the center of our system. Without it, life on Earth would be impossible, and our planet was formed along with this star. Therefore, it deserves special attention. A little about her. Like all stars, the Sun is mostly made up of hydrogen and helium. Moreover, the former constantly turns into the latter. As a result, heavier elements are formed. And the older the star, the more they accumulate.

In terms of age, the closest star to the 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 Sun's atmosphere consists of three parts: the corona, the chromosphere, and the photosphere.

Solar activity significantly affects the life of the 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.

When asked what is the name of the closest star to the Earth, many will not be able to answer correctly. The correct answer is actually very simple. The closest star to us is called the Sun.

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The Sun is the closest star to Earth

The bright ball that rises above the horizon every day is the closest star to us. It was formed about 4.5 billion years ago. The sun belongs to the group of young stars. Scientists believe that the appearance of the star, we owe the explosion of a supernova. This is confirmed by data on the anomalous amount of gold in the matter of the solar system. The luminary consists of hot gases and impurities of a relatively small amount of other elements.

Its chemical composition:

• hydrogen (70%);
• helium (28%);
• iron;
• nickel;
• oxygen;
• nitrogen;
• silicon;
• magnesium.

The sun produces an enormous amount of energy through nuclear fusion. Now these are reactions associated with the conversion of hydrogen into helium. The surface temperature is 5780 kelvin (approximately 5500 ̊С). According to the accepted classification, this is not the largest star in the universe, located in one of the arms of the Milky Way galaxy. Thanks to the gigantic force of gravity, the Sun has become the center around which the planets of the solar system, as well as asteroids, meteorites, cosmic dust, and other cosmic bodies revolve.

Interesting Facts:

• the star makes up 99.8% of the mass of our planetary system;
• here every second 4 billion tons of matter is converted into energy;
• 1300 planets like ours could fit inside;
• its diameter is equal to 109 diameters of the Earth;
• its mass is comparable to 332940 masses of the blue planet;
• The sun moves around the center of the galaxy at about 217 km/s;
• it is brighter than 85% of the stars in the Milky Way galaxy;
• the light of the Sun is actually almost white: it acquires a yellow tint as it passes through the Earth's atmosphere;
• photons of light from the surface of the star reach the planet Earth in 8 minutes;
• the Sun's magnetic field is very strong and can change its direction every 11 years;
• the solar wind, sunspots, flares and giant prominences arise under the action of a magnetic field;
• it is noticed that the cycles of solar activity last 11 years;
• geomagnetic storms on the planet simply would not exist without the magnetic field of the closest star, because they arise as a result of the interaction of force flows.

The closest star supports life on the blue planet. It is the source of light necessary for the process of photosynthesis. This ensures the creation of organics from inorganic substances, as well as the synthesis of oxygen. Without it, life would not have been possible. Thanks to photosynthesis, ancient plants obtained energy, which is contained in coal, oil, and other carbon-containing minerals. High doses of ultraviolet radiation from the Sun are dangerous for all living things, it is restrained by the ozone layer of the atmosphere. But at the same time, ultraviolet has antiseptic properties and is necessary for the production of vitamin D by the human body. Solar flares and strong fluctuations in its magnetic field can cause interruptions in the operation of electrical appliances and affect people's well-being.

The sun is the center of our planetary system, so the future of mankind is directly related to the future of the star, which is located closest to our planet. Now the luminary is approximately in the middle of its life cycle. Scientists have found that such stars exist on the main sequence for 10-12 million years. What future awaits our luminary?

Scientists have calculated:

• in 1.1 billion years, the Sun will increase its brightness by 11%, which threatens to end life on the Earth's surface;
• after 3.5 billion years, the Sun will become brighter by 40%; this will make the Earth like Venus in our time;
• after 6.4 billion years, the hydrogen in the core will run out, it will begin to shrink and become denser;
• another 7.7 billion years will pass and the Sun will inevitably become a red giant, the radius of which will be 206 times greater than the present one; if it does not swallow the Earth, water and atmosphere will definitely disappear from it;
• the mass of the Sun will not allow it to turn into a supernova, so then the phase of a planetary nebula and a white dwarf will follow; then the Sun will be the size of the Earth;
• in about 20 million years, the white dwarf will die out.

Now the question of which is the closest star to the blue planet will not take you by surprise. What is the name of the closest star besides the Sun? This is a more difficult question.

Distance from Earth to nearest star

Scientists have long calculated how many kilometers separate the Earth from the Sun. The distance from Earth to the nearest star is approximately 150 million kilometers. Because the Earth's orbit is elliptical, the exact value may vary. Astronomers call the minimum distance to the Sun perihelion (148 million km), and the maximum distance aphelion (152 million km). Aphelion is in July and perihelion is in January.

The closest star to the Earth, except for the Sun: not everything is so simple

After the Sun, closest to the blue planet is a very unusual star called Alpha Centauri. The distance to it is 4.37 light years. Alpha Centauri is not a single object.

It consists of three objects:

• Alpha Centauri A;
• Alpha Centauri B;
• Proxima Centauri.

They make revolutions around one joint center of gravity. But most of all we are interested in Proxima Centauri, which makes a complete revolution around the Alpha Centauri system in 500 thousand years. It is she who is closest to the Earth. The distance from it to the Earth is 4.23 light years. This is 270 thousand times the distance between the Earth and the Sun. Astronomers claim that it has been in this position for about 32 thousand years. And after 55 thousand years, according to scientists, this distance will decrease to 3.11 light years. The diameter of Proxima Centauri is less than the diameter of the Sun by 7 times. The mass is also about the same times less than the mass of our star.

Alpha Centauri is located in the constellation Centaurus, which is only visible from the Southern Hemisphere. It is impossible to see it with the naked eye. This is probably why astronomers saw Proxima Centauri only in 1915, and research on this most interesting object continues to this day. Scientists have been actively looking for planets around this star, but so far without success. Also, without a powerful telescope, it will not be possible to consider the closest star to Earth in the Northern Hemisphere. It is called Bernard's Star, is located at a distance of 5.978 light years in the constellation of Ophiuchus and belongs to the group of red dwarfs.

Of those stars that can be seen with the naked eye in the night sky, Sirius is the closest to Earth (8.6 light years). It is twice the size of the Sun in radius and mass. The second name of Sirius is Alpha Canis Major. There are no brighter stars in the night sky. In terms of brightness in the sky, it ranks sixth.

Only such celestial bodies shine brighter than Sirius:

1. Sun;

3. Jupiter;

4. Venus;

Due to its brightness, Sirius has long been an object of study and worship among various peoples of the world from different continents. It is visible from almost anywhere on the planet, although it belongs to the southern hemisphere of the starry sky. This is a double star. Sirius B is not as bright as Sirius A (the part of the system visible from Earth), but at the same time these space objects revolve around a common center of mass. The periodicity of this rotation is 50 years. Sirius B is a white dwarf, which means that it used to be much larger than Sirius A. Scientists estimate the age of Sirius at about 230 million years.

It now emits a bluish-white light, although researchers of older eras describe it as a bright red star. There is no scientific explanation for this fact yet. It is known that the bright appearance of Sirius from Earth is due to the fact that the star is close, and not to its own brightness. Astronomers have calculated that in our time, Sirius is approaching our planet at a speed of 7.6 km / s, so its apparent brightness will increase over time. Sirius is the eighth closest star to Earth.

List of stars by proximity to Earth:

• Sun;
• Alpha Centauri (Proxima Centauri);
• Star of Bernard;
• Luman 16;
• WISE 0855-0714;
• Wolf 395;
• Lalande 21185;
• Sirius.

Perhaps soon astronomers will make new discoveries, and this list will be replenished with new names of such distant, but at the same time close stars.