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Do you know which stars are closest to us?

The distances to the nearest stars to us were first determined in 1838 by the trigonometric parallax method, which is still in use. Of the approximately 100 billion stars in the Milky Way Galaxy, only about 2.5 million are close enough to us for their parallaxes to be measured with accuracy. Only three stars - Alpha Centauri, Procyon and Sirius - are on the list of the 20 brightest stars. Most relatively nearby stars are dimmer than the Sun and are invisible without the help of a telescope.

The sun

Stars closest to us: Sun

When asked what is the closest star to us, the answer is very simple, it is the Sun. The star around which our planet revolves, and all the others that make up the solar system. The sun is a star with a diameter of about 1,392,000 kilometers and by itself makes up 98.2% of total weight solar system.

The distance from the Sun to the Earth depends on its relative position, but the average is 149,600,000 km. Sunlight travels this distance in 8 minutes and 19 seconds, so if you look at the Sun, you will see it roughly as it was eight minutes ago. Imagine: if, for some bizarre reason, the Sun disappears at this exact moment, we will have sunlight within 8 minutes and 19 seconds.

Alpha Centauri

Stars closest to us: Alpha Centauri

Alpha Centauri (also known as Rigel Centauri) is the closest star system to the Sun, at a distance of 4.37 light-years (41.3 billion kilometers).

It consists of a system of three stars, gravitationally bound. A binary system of stars orbiting their center of mass, Alpha Centauri A and Alpha Centauri B, plus a third red dwarf star Proxima Centauri, which orbits 2 stars Alpha Centauri A and B.

The system also contains at least two Earth-sized planets Alpha Centauri Bb with approximately 113% of Earth's mass with a rotation period of 3236 days. Orbiting 6 million kilometers from a star at 1 or 4% of the distance from Earth to the Sun, the planet has an estimated surface temperature of at least 1500 K (approximately 1200 °C).

Star Barnard

Stars closest to us: Star Bernard

Diameter: 0.20 sun
Brightness: 0.000441 sun
Class: M4V
Temperature: 3000ºC
Orbital period: 4 days
Distance to Earth: 5.9 light years
Mass: 0.15 suns
Age: 10.000 million years

Barnard's Star, at 5.94 light-years (1.82 parsecs), is the fourth closest star to us and the second closest star system to our Sun after the trianic system of Alpha Centauri. It lies in the northernmost part of the constellation Ophiuchus, west of Chebelar (Beta Officers) and was discovered in 1916 by Edward E. Barnard.

Because it is a red dwarf, it cannot be seen from Earth without a powerful telescope.

Barnard's Star is approaching us at an unusual speed of 108 kilometers per second, so every century the distance decreases by 0.036 light years. Barnard's Star also features the largest movement of any star, about 10.4 arcseconds per year, or the equivalent of a lunar diameter every 180 years. This and its proximity make it an ideal candidate for extrasolar planetary exploration, as any wobble motion in its passage across the sky caused by orbiting worlds will be relatively large. However, planets around Barnard's Star have not been confirmed.

Luhman 16

Stars closest to us: Luhman 16

WISE 1049-5319 (its complete official name- WISE J104915.57-531906), also called Luhman 16, is a binary brown dwarf located in southern constellation Sail 6.5 light-years from the Sun, making these brown dwarfs the third closest star to the solar system, after Alpha Centauri (known since antiquity) and Barnard's Star (discovered in 1916).
The primary element, Luhman 16A, has a star rating of L8 ± 1, while the secondary element, Luhman 16B, is likely nearby. The pair orbit each other at a distance of about 3 AU. with an orbital period of about 25 years.

WISE 0855–0714

Stars closest to us: WISE-0855-0714

WISE 0855-0714 is one of the closest stars to our planet, and one of the coldest objects this type in space.

WISE 0855-0714 was discovered in 2014 by American astronomer Kevin Luhmann using the WISE infrared telescope, after which it was named. By its type, it belongs to the class of subbrown dwarfs - stars that, in terms of their weight, are below the limit of brown dwarfs. This star located in the constellation Hydra and is a single star.

The distance from WISE 0855–0714 to Earth is only 7.27 light years. This star is the fourth closest star to us, after the Alpha Centauri system, Barnard's Star and the binary star Luhmann 16. Exact age this star is unknown. It is believed to be between 1 and 10 billion years old.

WISE 0855-0714 has the coldest temperature in space among objects of its type. Astronomical research showed that the temperature of WISE 0855-0714 is in the range of 245 Kelvin, which is approximately -30 degrees Celsius. Further research WISE 0855–0714 continues to this day.

Wolf 359

Stars closest to us: Wolf 359

This extremely faint star is located just 7.8 light years from Earth in the constellation Leo. Like red dwarf stars in Earth's night sky, the star is too hazy to be seen by the naked human eye. Its correct motion was discovered by Max (Maximilian Franz Joseph Cornelius) Wolf (1863-1932), a pioneer of astrophotography, who discovered hundreds of variable stars and asteroids and about 5,000 nebulae by analyzing photographic plates.

Laland 21185

Stars closest to us: Laland 21185

Lalande 21185 is a red dwarf of spectral type M2.0V, whose effective temperature is 3526 K.2 It has a mass and diameter less than half that of the Sun. Its brightness just corresponds to 2% of the brightness of the sun and its relative abundance of elements that are heavier than helium is 52% of the sun (= -0.28). It moves perpendicular to the plane of the galaxy at a speed of 47 km/s. Although much older than the Sun, which is about 4600 million years old, Lalande 21185 is thought to be no more than 10,000 million years old.

Lalande 21185 is 8.31 light-years from the solar system and within 20,000 years, is only 4.7 light-years from Earth.

Sirius

Stars closest to us: Sirius

Sirius is the only bright star in the night sky.

It is located at a distance of 8.60 light years (2.64 parsecs) from Earth, in the constellation big dog. Sirius is not the best bright Star, but more visible than other stars because it is located so close to the solar system.

Sirius is slowly approaching Earth and will gradually increase in brightness over the next 60,000 years before it begins to recede. However, it will remain the brightest star seen on Earth for the next 210,000 years.

Sirius can be seen from almost anywhere inhabited place on the ground. Only those who live beyond the parallel of 73º, a few degrees above the arctic circle, cannot see this, for example, in St. Petersburg, where it reaches only 13º.93.

Sun as seen from the SDO satellite

The Sun, the closest star to the Earth, is a huge ball of hot plasma at the center of our system. It accounts for more than 99.86% of the mass of the solar system, it also provides all the energy needed for life on Earth. Ancient civilizations such as the Romans worshiped it because they believed it brought life. It received various names such as Sol for the Romans or Helios for the Greeks.

The diameter is 1,392,000 kilometers or 109 Earth diameters. It can fit 1,300,000 Earth-sized planets inside it. 8 planets and their satellites move around it, many dwarf planets, asteroids, comets and dust. Its mass eclipses that of any other object in the solar system.

It formed 4.6 billion years ago from a huge cloud of gas and dust called the protosolar nebula.

Over millions of years, this gas and dust condensed into stars and planets. As soon as gravity compressed the hydrogen enough to start a thermonuclear reaction, our star lit up.

The sun, the closest star to Earth, heats up very slowly. This will continue for another 7 billion years. After all the hydrogen reserves in the core run out, it will expand to a red giant, absorbing inner planets. At the end of its life, it will shed its outer layers and become a white dwarf.

Structure

The surface we see is called the photosphere, it has average temperature about 5800 degrees Kelvin. The surface consists of several layers - the photosphere, chromosphere and corona.

The structure of our star

As you go deeper into the depths, the temperature and pressure increase. At the core, the temperature is 15.7 million Kelvin, and the pressure is enough to maintain nuclear fusion. In the nucleus, as a result of thermonuclear fusion, protons combine into helium atoms, releasing great amount energy.

Activity

Despite the fact that our luminary consists entirely of plasma, it has a strong magnetic field. He has a north and a south magnetic poles, a lines of force magnetic field create noticeable activity that we see on the surface. For example, dark spots form when magnetic lines of force pierce the Sun's photosphere. And prominences, giant ejections of plasma, move along magnetic field lines.

Coronal mass ejections and flares occur when magnetic field lines realign.

Activity rises and falls over an 11-year cycle. At the lowest point, called the minimum, there are practically no spots on the surface. In the high point cycle-solar maximum, the number of sunspots is maximum.

The luminary constantly radiates a huge amount of heat and charged particles - wind. If we did not have a magnetic field, then charged particles would destroy all life on the planet. The winds carry charged particles to the edge, where they form a magnetic field that prevents the interstellar wind from penetrating from outside. This barrier is known as the heliopause, and without it, the solar system would be constantly exposed to cosmic rays.

Charged particles collide with satellites, power lines, disrupt radio communications, and cause the northern lights. Light is vital to our planet.

The sun appears yellow to us when it is actually white.

It seems so because of the influence of the atmosphere. It needs 1 month to turn around its axis. However, this is a rough estimate, because the star is a ball of plasma. Some parts spin faster than others, so it's hard to tell when it will complete a full rotation. For example, it takes 25.4 days to complete one revolution near the equator, and 36 days at the poles.

Compound

Our star is almost entirely composed of hydrogen (74%) and helium (25%), with impurities of other elements.

The nucleus is the main place where nuclear reactions synthesis.

Around the nucleus, there is a radiation zone where gamma ray photons are emitted and absorbed by hydrogen atoms. Sometimes a photon can take 100,000 years to cross radiation belt. Outside the radiation zone there is a convection zone, where the plasma rises and transfers energy to the surface, and then cooled down.

Only 5% of the stars in Milky Way larger than the Sun, the vast majority are small red dwarf stars.

Some of the most big stars, could be 100,000 times brighter and contain 100 times more mass than our star. Our star is a relatively young star. Old stars that formed billions of years ago contain far fewer heavy elements.

solar flares

This question can rightfully be considered classic, because despite all the evidence, for many people it causes difficulty. Once I asked it to a friend, and observed attempts to recall at least some famous stars. What was his surprise when I explained to him which star is closest to our planet.

What is the name of the closest star to Earth?

The answer is obvious - The sun, the only star of our solar system. The distance to it is “only” 150 million kilometers. Yes, too far :(

Other stars

You can look at this question from the other side, and try to answer, Which star is closest to our planet other than the Sun?. Many people know Alpha Centauri, the third most intense light in the starry sky. The distance to our planet is 4.35 light years however, this is not one star, a three-star system. The largest - Alpha Centauri, much larger and brighter than our luminary, and Alpha Centauri B significantly inferior in weight to our sun. The third member of this system is Proxima Centauri, a red dwarf. This is constellation available for observation only from areas southern hemisphere, but to distinguish red dwarf and it is completely impossible without armed with a powerful astronomical equipment.

How is the distance to stars measured?

This is possible through parallax. You can spend a small experiment. To do this, you need to clench your fist, stretch out your hand, and stretch thumb. As a target, you can use any remote object pointing your thumb at it. If you close one eye or the other in turn, you will notice that the finger is either opposite the target, or shifted to the side. This is the whole point of this method.

When determining the distance to cosmic body, calculate angle to object in relation to a certain landmark, the so-called reference point, during the period when the planet is at a certain point its orbit. The method applies only to those stars that are not further 100 light years from our planet.

The closest stars

Listed here stars and systems located at the minimum distance from our planet:

• Alpha Centauri- 4.35 light years;
• Star of Bernard- 5.9 light years;
• Wolf 359- 7.8 light years;
• Lalande 21186- 8.3 light years;

• Sirius- 8.6 light years.

In total, considering range of 14 light years, our "neighbors" it could be considered 32 star systems.

Everyone can say which star is closest to the Earth, but not everyone knows additional information about it.

This star belongs to the type of yellow dwarfs. And it appeared as much as 5 billion years ago. The light emitted by the Sun reaches the Earth in only 8 minutes at such a huge distance as about 150 million kilometers (this number is taken as 1 astronomical unit). This is the center of all planetary systems: 8 planets with satellites, many comets and meteorites revolve around it.

The mass of this star exceeds the mass of the Earth by about 330 thousand times, and the size is 109 times larger! For clarity, you can watch the video below, which clearly shows the scale of the planets with the Sun.

The sun is the brightest object in the entire sky. Thanks to the energy that the sun produces, life was born on Earth. Interestingly, it consists of only 90% hydrogen and 10% helium. The composition, of course, includes other substances, but their percentage is only 0.1%

First studies

Once upon a time, people thought that the Sun was not a moving object. This idea was destroyed by Galileo Galilei, because in 1610 he saw the movement of spots on the surface with his telescope. Based on this, it was concluded that it rotates. And it rotates, by the way, not like solid: in the equatorial region, the period of rotation around its axis is 25 days, and the period of rotation around the poles reaches 30 days. Making a rotation at a speed of about 200 -220 kilometers per second, for full turn around the center of the galaxy will take about 200 million years.

Sun and life on earth

This star releases just a huge amount of energy, or to be more precise, 6.5 kW from one square centimeter of surface. This energy, by the way, is unchanged throughout the life of the Sun. Interestingly, only a billionth of this energy will be enough for life on Earth. If the energy that will be transmitted to our planet changes up or down, life on Earth would most likely cease.

The sun is the basis of our system - the star closest to the Earth, which, unlike all other objects, we clearly see on a clear day. At night, the rest of the luminaries of the boundless space become available for observation. The number of stars filling the Universe cannot be counted. But the nearest celestial bodies located within a radius of 16, the scientists identified and compiled a list. It includes 57 star systems. Some of them are not single luminaries, but double and triple stars, therefore total celestial bodies reaches 64. The list also includes 13 brown dwarfs, significantly inferior to other objects in mass.

Only 7 stars from the list we can consider without the help of optical amplification - Alpha Centauri, Epsilon Eridani, Epsilon Indiana, Tau Ceti, 61 Cygnus. All of them have an apparent magnitude ranging from 1.43 to 6.03. Most of the luminaries belong to spectral class M (red), their temperature is 2600-3800 K. Hot stars are Sirius A, spectral type A (white), 9940 K and Procyon A, class F (yellow-white), 6650 K. The brown dwarfs included in the list are belong to additional spectral classes L, T, Y. The list also includes 4 white dwarfs of class D, which are rather rare objects in the visible sector of the Galaxy.

Characteristics of Alpha Centauri - the closest star system to Earth

The smallest distance - 4.22 light years - separates our planet from, one of the three elements of the Alpha Centauri star system. According to its characteristics, the star closest to the Earth (excluding the Sun) differs significantly from its neighbors. This luminary belongs to the spectral class M (red dwarf), and its mass and radius do not exceed 0.1 solar. Due to the low temperature - 3042 K - it emits little energy and is not detected by the naked eye. It was opened in 1915. Periodic and active flares increase the luminosity of the star. Proxima Centauri and the rest of its native system are separated by a significant distance of 0.21 light year, so whether it is in its orbit has not been reliably clarified. If they prove that Proxima is circling a binary star, then its full period exceeds 500 thousand years. The search for possible exoplanets near the star was unsuccessful, scientists rule out the presence major planets in its orbit.

The other two components of the system - Alpha Centauri A and Alpha Centauri B - closely interact with each other. From Earth, they are observed as one star. The distance to the system is 4.36 light years. Objects are assigned to the spectral classes G and K - these are yellow and orange dwarfs. In terms of their characteristics and temperature, they are similar to the Sun, but older than it, which reaches 6 billion years. The Centaurus A component is larger than the neighboring one, its mass is 1.1, and its diameter is 1.2 solar. Centaurus B values ​​are 0.9 and 0.86, respectively. The rotation of the luminaries occurs in an elliptical orbit, its angle of inclination is 79.2 degrees, their period is 79.9 years.

Exoplanets Alpha Centauri

The search for planets that are part of the systems of stars closest to us is carried out regularly. Special attention given to yellow and red dwarfs. To detect companions near distant objects, scientists have to measure the radial velocity of stars using spectrographs installed on the most powerful telescopes. The main studies were carried out by two independent groups: California and Geneva, which focused on a limited number of objects. Alpha Centauri is one of them. European astronomers were able to achieve positive results. In 2012, analyzing a record amount of data, they reported on a planet named Alpha Centauri B b. A clear signal, appearing at intervals of 3.2 days, marked a body with a mass of 1.13 Earth. The exoplanet is represented by a ball heated to 1200 degrees. This temperature is maintained due to the close placement of the orbit to the surface of the star. Its year is just over three Earth days. It does not fall into the conditional zone where life could originate, its size in this case is 0.5-0.9 AU. e. from the luminary.

Further research and computer modelling give hope for the presence of a second, larger and more distant planet near Alpha Centauri B, with a rotation period of 20.4 days. According to hypothetical calculations, the influence of Centaurus A will affect once every 70 years. With the presence of oceans, its desert surface will become much more vulnerable.

Barnard's Star

The star, discovered by E. Barnard in 1916 and named after him, belongs to the spectral class M. This is a red dwarf. Its location is the equatorial constellation Ophiuchus, at a distance of 5.96 light years from Earth. The small luminary is significantly inferior to our Sun, reaching 0.17 of its value in mass and diameter. The star is not visible to the naked eye, however, it is the fourth farthest from us. "Flying Barnard" is famous for its agility own movement, which is directed towards our Sun. One day she will be closer to us than Proxima Centauri. Its speed is a record, for a year it passes 10.36 arc seconds.

Presence of planets

A California team of scientists has been working for decades to find planets around Barnard's star, but so far there is no evidence of their existence.

Luman 16

The constellation Sails, located in southern hemisphere became a refuge dual system Brown dwarfs are the next closest neighbors of the Sun. The distance to Luhmann 16 was 6.59 light years. The two elements of the system are almost identical, their mass is 0.4-0.5 solar. The rotation period is two decades. No other bodies have been found in the vicinity of this binary star system.

earthly space ship, who went on a trip to our nearest neighbor Proxima Centauri, it will take 70 thousand years to get to her.

The distance between the components of the double star Alpha Centauri is 22 arc seconds. They merge when viewed with the naked eye, but separate when observed even in the simplest telescope. The angular distance between Centaurus A and B is not constant. In 2010, it was 6.74 arc seconds, and by 2016 it will be reduced to 4. Maximum value will be observed in 2056.

Among the stars close to us, only 3 belong to the luminaries of the first magnitude: Sirius, Alpha Centauri and Procyon, and the closest star to Earth is a red dwarf.