Our star system is the Milky Way. Interesting facts about the Milky Way galaxy

Astronomers say that with the naked eye a person can see about 4.5 thousand stars. And this, despite the fact that only a small part of one of the most amazing and unidentified pictures of the world is revealed to our eyes: only in the Galaxy Milky Way there are more than two hundred billion celestial bodies (scientists have the opportunity to observe only two billion).

The Milky Way is a barred spiral galaxy, representing a huge gravitationally bound star system in space. Together with the neighboring Andromeda and Triangulum galaxies and more than forty dwarf satellite galaxies, it is part of the Virgo Supercluster.

The age of the Milky Way exceeds 13 billion years, and during this time from 200 to 400 billion stars and constellations, more than a thousand huge gas clouds, clusters and nebulae have formed in it. If you look at a map of the Universe, you can see that the Milky Way is presented on it in the form of a disk with a diameter of 30 thousand parsecs (1 parsec is equal to 3.086 * 10 to the 13th power of kilometers) and an average thickness of about a thousand light years (one light year almost 10 trillion kilometers).

Astronomers find it difficult to answer exactly how much the Galaxy weighs, since most of the weight is contained not in the constellations, as previously thought, but in dark matter, which does not emit or interact with electromagnetic radiation. According to very rough calculations, the weight of the Galaxy ranges from 5*10 11 to 3*10 12 solar masses.

Like all celestial bodies, the Milky Way rotates around its axis and moves around the Universe. It should be taken into account that when moving, galaxies constantly collide with each other in space and the one that has larger sizes absorbs smaller ones, but if their sizes coincide, active star formation begins after the collision.

Thus, astronomers suggest that in 4 billion years the Milky Way in the Universe will collide with the Andromeda Galaxy (they are approaching each other at a speed of 112 km/s), causing the emergence of new constellations in the Universe.

As for the movement around its axis, the Milky Way moves unevenly and even chaotically in space, since each star system, cloud or nebula located in it has its own speed and orbits different types and forms.

Galaxy structure

If you look closely at a map of space, you can see that the Milky Way is very compressed in the plane and looks like a “flying saucer” ( solar system located almost at the very edge of the star system). The Milky Way Galaxy consists of a core, a bar, a disk, spiral arms and a crown.

Core

The core is located in the constellation Sagittarius, where there is a source of non-thermal radiation, the temperature of which is about ten million degrees - a phenomenon characteristic only of the nuclei of galaxies. In the center of the core there is a compaction - a bulge, consisting of large number old stars moving in an elongated orbit, many of which are at the end of their life cycle.

So, some time ago, American astronomers discovered an area here measuring 12 by 12 parsecs, consisting of dead and dying constellations.

At the very center of the core is a supermassive black hole(plot in outer space, which has such powerful gravity that even light is unable to leave it), around which a smaller black hole rotates. Together they exert such a strong gravitational influence on nearby stars and constellations that they move in unusual directions. celestial bodies trajectories in the Universe.

Also, the center of the Milky Way is characterized by an extremely strong concentration of stars, the distance between which is several hundred times less than at the periphery. The speed of movement of most of them is absolutely independent of how far they are from the core, and therefore average speed rotation ranges from 210 to 250 km/s.

Jumper

The bridge, 27 thousand light years in size, crosses the central part of the Galaxy at an angle of 44 degrees to the conventional line between the Sun and the core of the Milky Way. It consists mainly of old red stars (about 22 million), and is surrounded by a gas ring that contains most of the molecular hydrogen, and is therefore a region where stars are formed in the greatest number. According to one theory, such active star formation occurs in the bridge due to the fact that it passes gas through itself, from which constellations are born.

Disk

The Milky Way is a disk consisting of constellations, gas nebulae and dust (its diameter is about 100 thousand light years with a thickness of several thousand). The disk rotates much faster than the corona, which is located at the edges of the Galaxy, while the rotation speed at different distances from the core is unequal and chaotic (varies from zero in the core to 250 km/h at a distance of 2 thousand light years from it). Gas clouds, as well as young stars and constellations, are concentrated near the plane of the disk.

On the outer side of the Milky Way there are layers of atomic hydrogen, which extend into space one and a half thousand light years from the outer spirals. Despite the fact that this hydrogen is ten times thicker than in the center of the Galaxy, its density is just as many times lower. On the outskirts of the Milky Way, dense accumulations of gas with a temperature of 10 thousand degrees, the dimensions of which exceed several thousand light years, were discovered.

Spiral sleeves

Immediately behind the gas ring there are five main spiral arms of the Galaxy, the size of which ranges from 3 to 4.5 thousand parsecs: Cygnus, Perseus, Orion, Sagittarius and Centauri (the Sun is located on the inner side of the Orion arm). Molecular gas is located unevenly in the arms and does not always obey the rules of rotation of the Galaxy, introducing errors.

Crown

The Milky Way's corona appears as a spherical halo that extends five to ten light years beyond the Galaxy. The corona consists of globular clusters, constellations, individual stars (mostly old and low-mass), dwarf galaxies, and hot gas. They all move around the core in elongated orbits, and the rotation of some stars is so random that even the speed of nearby stars can differ significantly, so the corona rotates extremely slowly.

According to one hypothesis, the corona arose as a result of the absorption of smaller galaxies by the Milky Way, and therefore is their remnants. According to preliminary data, the age of the halo exceeds twelve billion years and is the same age as the Milky Way, and therefore star formation here has already completed.

star space

If you look at the night starry sky, the Milky Way can be seen from absolutely any point globe in the form of a strip of lightish color (since our star system is located inside the Orion arm, only part of the Galaxy is accessible for viewing).

The map of the Milky Way shows that our Sun is located almost on the disk of the Galaxy, at its very edge, and its distance to the core is from 26-28 thousand light years. Considering that the Sun moves at a speed of about 240 km/h, to make one revolution, it needs to spend about 200 million years (over the entire period of its existence, our star has not flown around the Galaxy thirty times).

It is interesting that our planet is located in a corotation circle - a place where the speed of rotation of stars coincides with the speed of rotation of the arms, so stars never leave these arms or enter them. This circle is characterized by high level radiation, therefore it is believed that life can only arise on planets near which there are very few stars.

This fact also applies to our Earth. Being on the periphery, it is located in a fairly calm place in the Galaxy, and therefore for several billion years it was almost not subject to global cataclysms, for which the Universe is so rich. Perhaps this is one of the main reasons that life was able to originate and survive on our planet.

Planet Earth, solar system, and all stars visible to the naked eye are in Milky Way Galaxy, which is a barred spiral galaxy that has two distinct arms starting at the ends of the bar.

This was confirmed in 2005 by the Lyman Spitzer Space Telescope, which showed that the central bar of our galaxy is larger than previously thought. Spiral galaxies barred - spiral galaxies with a bar (“bar”) of bright stars extending from the center and crossing the galaxy in the middle.

Spiral branches in such galaxies begin at the ends of the bars, whereas in ordinary spiral galaxies ah they come directly from the core. Observations show that about two-thirds of all spiral galaxies are barred. According to existing hypotheses, bridges are centers of star formation that support the birth of stars in their centers. It is assumed that, through orbital resonance, they allow gas from the spiral arms to pass through them. This mechanism provides the influx of building material for the birth of new stars. The Milky Way, together with the Andromeda galaxy (M31), Triangulum galaxy (M33), and more than 40 smaller satellite galaxies form the Local Group of Galaxies, which, in turn, is part of the Virgo Supercluster. "Using infrared imaging from NASA's Spitzer Telescope, scientists have discovered that the Milky Way's elegant spiral structure has only two dominant arms from the ends of a central bar of stars. Previously, our galaxy was thought to have four main arms."

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In appearance, the galaxy resembles a disk (since the bulk of the stars are located in the form of a flat disk) with a diameter of about 30,000 parsecs (100,000 light years, 1 quintillion kilometers) with an estimated average thickness of the disk of the order of 1000 light years, the diameter of the bulge is The center of the disk is 30,000 light years away. The disk is immersed in a spherical halo, and around it is a spherical corona. The center of the galactic core is located in the constellation Sagittarius. The thickness of the galactic disk at the location where it is located solar system with planet Earth is 700 light years. The distance from the Sun to the center of the Galaxy is 8.5 kiloparsecs (2.62.1017 km, or 27,700 light years). solar system is on inner edge arm called the Orion Arm. In the center of the Galaxy, there appears to be a supermassive black hole (Sagittarius A*) (about 4.3 million solar masses) around which the black hole presumably rotates average weight from 1000 to 10,000 solar masses and an orbital period of about 100 years and several thousand relatively small ones. The galaxy contains, according to the lowest estimate, about 200 billion stars ( modern assessment ranges from 200 to 400 billion). As of January 2009, the mass of the Galaxy is estimated at 3.1012 solar masses, or 6.1042 kg. The bulk of the Galaxy is contained not in stars and interstellar gas, but in a non-luminous halo of dark matter.

Compared to the halo, the Galaxy's disk rotates noticeably faster. The speed of its rotation is not the same at different distances from the center. It rapidly increases from zero at the center to 200-240 km/s at a distance of 2 thousand light years from it, then decreases somewhat, increases again to approximately the same value and then remains almost constant. Studying the peculiarities of the rotation of the Galaxy's disk made it possible to estimate its mass; it turned out that it is 150 billion times greater than the mass of the Sun. Age Milky Way galaxies equals13,200 million years old, almost as old as the Universe. The Milky Way is part of the Local Group of galaxies.

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Together with other stars, the Sun rotates around the center of the Galaxy at a speed of 220-240 km/s, making one revolution in approximately 225-250 million years (which is one galactic year). Thus, during its entire existence, the Earth has flown around the center of the Galaxy no more than 30 times. The galactic year of the Galaxy is 50 million years, the period of revolution of the jumper is 15-18 million years. In the vicinity of the Sun, it is possible to trace sections of two spiral arms that are approximately 3 thousand light years away from us. Based on the constellations where these areas are observed, they were given the name Sagittarius Arm and Perseus Arm. The sun is located almost in the middle between these spiral branches. But relatively close to us (by galactic standards), in the constellation Orion, there passes another, not very clearly defined arm - the Orion Arm, which is considered a branch of one of the main spiral arms of the Galaxy. The speed of the Sun's rotation around the center of the Galaxy almost coincides with the speed of the compaction wave forming the spiral arm. This situation is atypical for the Galaxy as a whole: the spiral arms rotate at a constant angular velocity, like spokes in a wheel, and the movement of stars occurs according to a different pattern, so almost the entire stellar population of the disk either falls inside the spiral arms or falls out of them. The only place where the velocities of stars and spiral arms coincide is the so-called corotation circle, and it is on it that the Sun is located. For the Earth, this circumstance is extremely important, since violent processes occur in the spiral arms, generating powerful radiation that is destructive for all living things. And no atmosphere could protect from it. But our planet exists in a relatively calm place in the Galaxy and has not been affected by these cosmic cataclysms for hundreds of millions (or even billions) of years. Perhaps this is why life was able to be born and preserved on Earth, the age of which is estimated at 4.6 billion years. A diagram of the location of the Earth in the Universe in a series of eight maps that show, from left to right, starting with the Earth, moving in solar system, to neighboring star systems, to the Milky Way, to local Galactic groups, tolocal Virgo superclusters, on our local supercluster, and ends in the observable Universe.

Solar System: 0.001 light years

Neighbors in interstellar space

Milky Way: 100,000 light years

Local Galactic Groups

Local Virgo Supercluster

Local above a cluster of galaxies

Observable Universe

The solar system is immersed in a huge star system - the Galaxy, numbering hundreds of billions of stars of very different luminosity and color (Stars in the section: “Life of stars”). Properties different types The stars of the Galaxy are quite well known to astronomers. Our neighbors are not just typical stars and other celestial objects, but rather representatives of the most numerous “tribes” of the Galaxy. At present, all or almost all stars in the vicinity of the Sun have been studied, with the exception of very dwarf ones, which emit very little light. Most of them are very faint red dwarfs - their masses are 3-10 times less than that of the Sun. Stars similar to the Sun are very rare, only 6% of them. Many of our neighbors (72%) are grouped into multiple systems, where the components are connected to each other by gravitational forces. Which of the hundreds of nearby stars can claim the title of the closest neighbor of the Sun? Now it is considered a component of the famous triple system Alpha Centauri - the faint red dwarf Proxima. The distance to the proxima is 1.31 pc, the light from it travels to us in 4.2 years. Statistics of the circumsolar population provide insight into the evolution of the galactic disk and the galaxy as a whole. For example, the luminosity distribution of solar-type stars shows that the age of the disk is 10-13 billion years.

In the 17th century, after the invention of the telescope, scientists first realized how large the number of stars is in outer space. In 1755, the German philosopher and naturalist Immanuel Kant proposed that stars form groups in the cosmos, just as the planets form the solar system. He called these groups “star islands.” According to Kant, one of these countless islands is the Milky Way - a grandiose cluster of stars, visible in the sky as a light, foggy stripe. In ancient Greek, the word "galaktikos" means "milky", which is why the Milky Way and similar star systems are called galaxies.

Dimensions and structure of our Galaxy

Based on the results of his calculations, Herschel attempted to determine the size and forms a kind of thick disk: in the plane of the Milky Way it extends to a distance of no more than 850 units, and in the perpendicular direction - to 200 units, if we take the distance to Sirius as one. According to the modern distance scale, this corresponds to 7300X1700 light years. This estimate generally correctly reflects the structure of the Milky Way, although it is highly imprecise. The fact is that in addition to stars, the Galaxy’s disk also includes numerous gas and dust clouds that weaken the light of distant stars. The first explorers of the Galaxy did not know about this absorbing substance and believed that they saw all its stars.

The true size of the Galaxy was established only in the 20th century. It turned out that it is a much flatter formation than previously thought. The diameter of the galactic disk exceeds 100 thousand light years, and the thickness is about 1000 light years. Due to the fact that the Solar System is located practically in the plane of the Galaxy, filled with absorbing matter, many details of the structure of the Milky Way are hidden from the view of an earthly observer. However, they can be studied using the example of other galaxies similar to Shasha. So, in the 40s. XX century, observing the galaxy M 31, better known as the Andromeda nebula, German astronomer Walter Baade noticed that the flat lens-shaped disk of this huge galaxy is immersed in a more rarefied spherical star cloud - a halo. Since the nebula is very similar to our Galaxy, he suggested that the Milky Way also has a similar structure. Galactic disk stars were called population type I, and halo stars were called population type II.

As modern research shows, the two types of stellar populations differ not only in their spatial position, but also in the nature of their motion, as well as their chemical composition. These features are associated primarily with the different origin of the disk and the spherical component.

Galaxy Structure: Halo

The boundaries of our Galaxy are determined by the size of the halo. The radius of the halo is significantly larger than the size of the disk and, according to some data, reaches several hundred thousand light years. The center of symmetry of the Milky Way halo coincides with the center of the galactic disk. The halo consists mainly of very old, dim, low-mass stars. They occur individually and in globular clusters that can contain more than a million stars. The age of the population of the spherical component of the Galaxy exceeds 12 billion years. It is usually taken to be the age of the Galaxy itself. A characteristic feature of halo stars is the extremely small proportion of heavy chemical elements in them. The stars that form globular clusters contain hundreds of times less metal than the Sun.

Stars of the spherical component are concentrated towards the center of the Galaxy. The central, densest part of the halo within several thousand light years from the center of the Galaxy is called the “bulge” (“thickening”). Stars and halo star clusters move around the center of the Galaxy in very elongated orbits. Because individual stars rotate almost randomly, the halo as a whole rotates very slowly.

Structure of the Galaxy: Disk

Compared to a halo, the disk rotates noticeably faster. The speed of its rotation is not the same at different distances from the center. It quickly increases from zero at the center to 200-240 km/s at a distance of 2 thousand light years from it, then decreases somewhat, increases again to approximately the same value and then remains almost constant. Studying the characteristics of the disk's rotation made it possible to estimate its mass. It turned out that it is 150 billion times the mass of the Sun. The population of the disk is very different from the population of the halo. Young stars and star clusters, whose age does not exceed several billion years, are concentrated near the plane of the disk. They form the so-called flat component. There are a lot of bright and hot stars among them.

The gas in the Galaxy's disk is also concentrated mainly near its plane. It is located unevenly, forming numerous gas clouds - giant superclouds, heterogeneous in structure, extending several thousand light years to small clouds no larger than a parsec in size. The main chemical element in our Galaxy is hydrogen. Approximately 1/4 of it consists of helium. Compared to these two elements, the others are present in very small quantities. On average, the chemical composition of the stars and gas in the disk is almost the same as that of the Sun.

Structure of the Galaxy: Core

One of the most interesting areas of the Galaxy is considered to be its center, or core, located in the direction of the constellation Sagittarius. The visible radiation from the central regions of the Galaxy is completely hidden from us by thick layers of absorbing matter. Therefore, it began to be studied only after the creation of receivers of infrared and radio radiation, which are absorbed to a lesser extent. The central regions of the Galaxy are characterized by a strong concentration of stars: each cubic parsec near the center contains many thousands of them. The distances between stars are tens and hundreds of times smaller than in the vicinity of the Sun. If we lived on a planet near a star located near the core of the Galaxy, then dozens of stars would be visible in the sky, comparable in brightness to the Moon, and many thousands brighter than the most bright stars our sky.

In addition to a large number of stars, in the central region of the Galaxy there is a circumnuclear gas disk consisting mainly of molecular hydrogen. Its radius exceeds 1000 light years. Closer to the center, areas of ionized hydrogen and numerous sources of infrared radiation are noted, indicating star formation occurring there. In the very center of the Galaxy, the existence of a massive compact object is assumed - a black hole with a mass of about a million solar masses. In the center there is also a bright radio source, Sagittarius A, the origin of which is associated with the activity of the nucleus.

The Milky Way Galaxy is very majestic and beautiful. This huge world- our Motherland, our Solar system. All the stars and other objects that are visible to the naked eye in the night sky are our galaxy. Although there are some objects that are located in the Andromeda Nebula, a neighbor of our Milky Way.

Description of the Milky Way

The Milky Way Galaxy is huge, 100 thousand light years in size, and, as you know, one light year is equal to 9460730472580 km. Our solar system is located 27,000 light years from the center of the galaxy, in one of the arms called the Orion arm.

Our solar system orbits the center of the Milky Way galaxy. This happens in the same way as the Earth rotates around the Sun. The solar system completes a revolution every 200 million years.

Deformation

The Milky Way Galaxy appears as a disk with a bulge in the center. He doesn't perfect shape. On one side there is a bend north of the center of the galaxy, and on the other it goes down, then turns to the right. Outwardly, this deformation somewhat resembles a wave. The disk itself is deformed. This is due to the presence of the Small and Large Magellanic Clouds nearby. They rotate around the Milky Way very quickly - this was confirmed by the Hubble telescope. These two dwarf galaxies are often called satellites of the Milky Way. The clouds create a gravitationally bound system that is very heavy and quite massive due to the heavy elements in the mass. It is assumed that they are like a tug of war between galaxies, creating vibrations. As a result, the Milky Way galaxy is deformed. The structure of our galaxy is special; it has a halo.

Scientists believe that in billions of years the Milky Way will absorb the Magellanic Clouds, and after some time it will be absorbed by Andromeda.

Halo

Wondering what kind of galaxy the Milky Way is, scientists began to study it. They managed to find out that 90% of its mass consists of dark matter, which is why a mysterious halo appears. Everything that is visible to the naked eye from Earth, namely that luminous matter, is approximately 10% of the galaxy.

Numerous studies have confirmed that the Milky Way has a halo. Scientists compiled various models, which took into account the invisible part and without it. After experiments, it was suggested that if there were no halo, then the speed of movement of the planets and other elements of the Milky Way would be less than now. Because of this feature, it was assumed that most of the components consist of invisible mass or dark matter.

Number of stars

The Milky Way galaxy is considered one of the most unique. The structure of our galaxy is unusual; there are more than 400 billion stars in it. About a quarter of them are large stars. Note: other galaxies have fewer stars. There are about ten billion stars in the Cloud, some others consist of a billion, and in the Milky Way there are more than 400 billion of the most different stars, and only a small part is visible from Earth, about 3000. It is impossible to say exactly how many stars are contained in the Milky Way, since the galaxy is constantly losing objects due to their transformation into supernovae.

Gases and dust

Approximately 15% of the galaxy is dust and gases. Maybe because of them our galaxy is called the Milky Way? Despite its enormous size, we can see about 6,000 light years ahead, but the size of the galaxy is 120,000 light years. It may be larger, but even the most powerful telescopes cannot see beyond that. This is due to the accumulation of gas and dust.

Thickness does not allow dust to pass through visible light, but infrared light passes through it, allowing scientists to create star maps.

What happened before

According to scientists, our galaxy has not always been like this. The Milky Way was created by the merger of several other galaxies. This giant captured other planets and areas, which had a strong impact on the size and shape. Even now, planets are being captured by the Milky Way galaxy. An example of this is objects Canis Major- a dwarf galaxy located near our Milky Way. Canis stars are periodically added to our universe, and from ours they move to other galaxies, for example, objects are exchanged with the Sagittarius galaxy.

View of the Milky Way

Not a single scientist or astronomer can say exactly what our Milky Way looks like from above. This is due to the fact that Earth is located in the Milky Way galaxy, 26,000 light years from the center. Because of this location, it is not possible to take pictures of the entire Milky Way. Therefore, any image of a galaxy is either pictures of other visible galaxies or someone's imagination. And we can only guess what she really looks like. There is even a possibility that we now know as much about it as the ancient people who believed the Earth to be flat.

Center

The center of the Milky Way galaxy is called Sagittarius A* - a great source of radio waves, suggesting that there is a huge black hole at its very heart. According to assumptions, its size is a little more than 22 million kilometers, and this is the hole itself.

All the substances that try to get into the hole form a huge disk, almost 5 million times larger than our Sun. But even this retraction force does not prevent new stars from forming at the edge of the black hole.

Age

Based on estimates of the composition of the Milky Way galaxy, it was possible to establish an estimated age of about 14 billion years. The oldest star is just over 13 billion years old. The age of a galaxy is calculated by determining the age of the oldest star and the phases preceding its formation. Based on the available data, scientists have suggested that our universe is about 13.6-13.8 billion years old.

First, the bulge of the Milky Way was formed, then its middle part, in the place of which a black hole subsequently formed. Three billion years later, a disk with sleeves appeared. Gradually it changed, and only about ten billion years ago it began to look the way it does now.

We are part of something bigger

All the stars in the Milky Way galaxy are part of a larger galactic structure. We are part of the Virgo Supercluster. The closest galaxies to the Milky Way, such as the Magellanic Cloud, Andromeda and other fifty galaxies, are one cluster, the Virgo Supercluster. A supercluster is a group of galaxies that occupies a huge area. And this is only a small part of the stellar surroundings.

The Virgo Supercluster contains more than a hundred groups of clusters over an area more than 110 million light-years in diameter. The Virgo cluster itself is a small part of the Laniakea supercluster, and it, in turn, is part of the Pisces-Cetus complex.

Rotation

Our Earth moves around the Sun, making a full revolution in 1 year. Our Sun orbits in the Milky Way around the center of the galaxy. Our galaxy moves in relation to a special radiation. CMB radiation is a convenient reference point that allows you to determine the speed of a wide variety of matters in the Universe. Studies have shown that our galaxy rotates at a speed of 600 kilometers per second.

Appearance of the name

The galaxy got its name because of its special appearance, reminiscent of spilled milk in the night sky. The name was given to it back in Ancient Rome. Back then it was called the “milk road.” It is still called that way - the Milky Way, associating the name specifically with appearance white streak on the night sky, with spilled milk.

References to the galaxy have been found since the era of Aristotle, who said that the Milky Way is a place where celestial spheres contact with earthly ones. Until the telescope was created, no one added anything to this opinion. And only from the seventeenth century people began to look at the world differently.

Our neighbors

For some reason, many people think that the closest galaxy to the Milky Way is Andromeda. But this opinion is not entirely correct. Our closest “neighbor” is the Canis Major galaxy, located inside the Milky Way. It is located at a distance of 25,000 light years from us, and 42,000 light years from the center. In fact, we are closer to Canis Major than to the black hole at the center of the galaxy.

Before the discovery of Canis Major at a distance of 70 thousand light years, Sagittarius was considered the closest neighbor, and after that the Large Magellanic Cloud. Opened in Pse unusual stars with huge class M density.

According to the theory, the Milky Way swallowed Canis Major along with all its stars, planets and other objects.

Collision of galaxies

IN lately Information is increasingly being found that the closest galaxy to the Milky Way, the Andromeda Nebula, will swallow our universe. These two giants formed at about the same time - about 13.6 billion years ago. It is believed that these giants are capable of uniting galaxies, but due to the expansion of the Universe they should move away from each other. But, contrary to all the rules, these objects are moving towards each other. The speed of movement is 200 kilometers per second. It is estimated that in 2-3 billion years Andromeda will collide with Milky Way.

Astronomer J. Dubinsky created a model of the collision shown in this video:

The collision will not lead to a catastrophe on a global scale. And after several billion years it will form new system, with familiar galactic shapes.

Lost galaxies

Scientists conducted a large-scale study of the starry sky, covering approximately an eighth of it. As a result of an analysis of the star systems of the Milky Way galaxy, it was possible to find out that there are previously unknown streams of stars on the outskirts of our universe. This is all that remains of small galaxies that were once destroyed by gravity.

The telescope installed in Chile took a huge number of images that allowed scientists to assess the sky. The images estimate that our galaxy is surrounded by a halo of dark matter, thin gas and few stars, remnants of dwarf galaxies that were once swallowed up by the Milky Way. Having a sufficient amount of data, scientists were able to assemble a “skeleton” of dead galaxies. It’s like in paleontology - it’s difficult to say from a few bones what a creature looked like, but with enough data, you can collect a skeleton and guess what the lizard was like. So it is here: the information content of the images made it possible to recreate eleven galaxies that were swallowed up by the Milky Way.

Scientists are confident that as they observe and evaluate the information they receive, they will be able to find several more new disintegrated galaxies that were “eaten” by the Milky Way.

We're under fire

According to scientists, the hypervelocity stars located in our galaxy did not originate in it, but in the Large Magellanic Cloud. Theorists cannot explain many aspects regarding the existence of such stars. For example, it is impossible to say exactly why it is concentrated large number hypervelocity stars in Sextant and Leo. Having revised the theory, scientists came to the conclusion that such a speed can only develop due to the influence of a black hole located in the center of the Milky Way.

Recently, more and more stars have been discovered that do not move from the center of our galaxy. After analyzing the trajectory of ultra-fast stars, scientists were able to find out that we are under attack from the Large Magellanic Cloud.

Death of the planet

By observing the planets in our galaxy, scientists were able to see how the planet died. She was consumed by the aging star. During the expansion and transformation into a red giant, the star absorbed its planet. And another planet in the same system changed its orbit. Having seen this and assessed the state of our Sun, scientists came to the conclusion that the same thing would happen to our luminary. In about five million years it will become a red giant.

How the galaxy works

Our Milky Way has several arms that rotate in a spiral. The center of the entire disk is a gigantic black hole.

We can see the galactic arms in the night sky. They look like white stripes, reminiscent of a milk road that is strewn with stars. These are the branches of the Milky Way. They are best seen in clear weather in the warm season, when there is the most cosmic dust and gases.

The following arms are distinguished in our galaxy:

1. Angle branch.
2. Orion. Our solar system is located in this arm. This sleeve is our “room” in the “house”.
3. Carina-Sagittarius sleeve.
4. Perseus branch.
5. Branch of the Shield of the Southern Cross.

It also contains a core, a gas ring, dark matter. It supplies about 90% of the entire galaxy, and the remaining ten are visible objects.

Our Solar System, the Earth and other planets are a single whole of a huge gravitational system that can be seen every night in a clear sky. In our “home” a variety of processes are constantly taking place: stars are born, they decay, we are bombarded by other galaxies, dust and gases appear, stars change and go out, others flare up, they dance around... And all this happens somewhere out there, far away in a universe about which we know so little. Who knows, maybe the time will come when people will be able to reach other branches and planets of our galaxy in a matter of minutes, and travel to other universes.

Planet Earth, the Solar System, billions of other stars and celestial bodies - all this is our Milky Way galaxy - a huge intergalactic formation, where everything obeys the laws of gravity. Data on the true size of the galaxy are only approximate. And the most interesting thing is that there are hundreds, maybe even thousands, of such formations, larger or smaller, in the Universe.

The Milky Way Galaxy and what surrounds it

All celestial bodies, including the Milky Way planets, satellites, asteroids, comets and stars, are constantly in motion. Born in a cosmic vortex big bang, all these objects are on the path of their development. Some have more ancient age, others are clearly younger.

The gravitational formation rotates around the center, while individual parts of the galaxy rotate with at different speeds. If in the center the rotation speed of the galactic disk is quite moderate, then at the periphery this parameter reaches values ​​of 200-250 km/s. The Sun is located in one of these areas, closer to the center of the galactic disk. The distance from it to the center of the galaxy is 25-28 thousand light years. The Sun and the Solar System complete a full revolution around the central axis of the gravitational formation in 225-250 million years. Accordingly, in the entire history of its existence, the Solar System has flown around the center only 30 times.

Place of the galaxy in the Universe

One notable feature should be noted. The position of the Sun and, accordingly, the planet Earth is very convenient. The galactic disk is constantly undergoing a process of compaction. This mechanism is caused by the discrepancy between the speed of rotation of the spiral branches and the movement of stars, which move within the galactic disk according to their own laws. During compaction, violent processes occur, accompanied by powerful ultraviolet radiation. The Sun and Earth are comfortably located in the corotational circle, where such vigorous activity is absent: between two spiral branches on the border of the Milky Way arms - Sagittarius and Perseus. This explains the calm in which we remain so long time. For more than 4.5 billion years, we have not been affected by cosmic disasters.

Structure of the Milky Way galaxy

The galactic disk is not homogeneous in its composition. Like other spiral gravitational systems, the Milky Way has three distinguishable regions:

• a core formed by a dense star cluster containing a billion stars of varying ages;
• the galactic disk itself, formed from clusters of stars, stellar gas and dust;
• corona, spherical halo - the region in which globular clusters, dwarf galaxies are located, separate groups stars, cosmic dust and gas.

Near the plane of the galactic disk there are young stars collected in clusters. The density of star clusters in the center of the disk is higher. Near the center, the density is 10,000 stars per cubic parsec. In the region where the Solar System is located, the density of stars is already 1-2 stars per 16 cubic parsecs. As a rule, the age of these celestial bodies is no more than several billion years.

Interstellar gas also concentrates around the plane of the disk, subject to centrifugal forces. Despite the constant speed of rotation of the spiral branches, the interstellar gas is distributed unevenly, forming large and small zones of clouds and nebulae. However, the main galactic building material is dark matter. Its mass prevails over the total mass of all celestial bodies that make up the Milky Way galaxy.

If in the diagram the structure of the galaxy is quite clear and transparent, then in reality it is almost impossible to examine the central regions of the galactic disk. Gas and dust clouds and clusters of stellar gas hide from our view the light from the center of the Milky Way, in which lives a real space monster - a supermassive black hole. The mass of this supergiant is approximately 4.3 million M☉. Next to the supergiant is a smaller black hole. This gloomy company is complemented by hundreds of dwarf black holes. The black holes of the Milky Way are not only devourers of stellar matter, but also act as a maternity hospital, throwing huge bunches of protons, neutrons and electrons into space. It is from them that atomic hydrogen is formed - the main fuel of the star tribe.

The jumper bar is located in the region of the galactic core. Its length is 27 thousand light years. Old stars reign here, red giants, whose stellar matter feeds black holes. The bulk of molecular hydrogen is concentrated in this region, which acts as the main building material for the star formation process.

Geometrically, the structure of the galaxy looks quite simple. Each spiral arm, and there are four of them in the Milky Way, originates from a gas ring. The sleeves diverge at an angle of 20⁰. At the outer boundaries of the galactic disk, the main element is atomic hydrogen, which spreads from the center of the galaxy to the periphery. The thickness of the hydrogen layer on the outskirts of the Milky Way is much wider than in the center, while its density is extremely low. The discharge of the hydrogen layer is facilitated by the influence of dwarf galaxies, which have been closely following our galaxy for tens of billions of years.

Theoretical models of our galaxy

Even ancient astronomers tried to prove that the visible stripe in the sky is part of a huge stellar disk rotating around its center. This statement was supported by the mathematical calculations carried out. It was possible to get an idea of ​​our galaxy only thousands of years later, when they came to help science instrumental methods space exploration. A breakthrough in the study of the nature of the Milky Way was the work of the Englishman William Herschel. In 1700, he was able to experimentally prove that our galaxy is disk-shaped.

Already in our time, research has taken a different turn. Scientists relied on comparing the movements of stars between which there were different distances. Using the parallax method, Jacob Kaptein was able to approximately determine the diameter of the galaxy, which, according to his calculations, is 60-70 thousand light years. Accordingly, the place of the Sun was determined. It turned out that it is located relatively far from the raging center of the galaxy and at a considerable distance from the periphery of the Milky Way.

The fundamental theory of the existence of galaxies is that of the American astrophysicist Edwin Hubble. He came up with the idea to classify all gravitational formations, dividing them into elliptical galaxies and spiral-type formations. The latter, spiral galaxies, represent the largest group, which includes formations of various sizes. The largest recently discovered spiral galaxy is NGC 6872, which has a diameter of more than 552 thousand light years.

Expected future and forecasts

The Milky Way Galaxy appears to be a compact and orderly gravitational formation. Unlike our neighbors, our intergalactic home is quite calm. Black holes systematically influence the galactic disk, reducing it in size. This process has already lasted tens of billions of years and how much longer it will continue is unknown. The only threat looming over our galaxy comes from its nearest neighbor. The Andromeda Galaxy is rapidly approaching us. Scientists suggest that a collision of two gravitational systems could occur in 4.5 billion years.

Such a meeting-merger will mean the end of the world in which we are accustomed to living. The Milky Way, which is smaller in size, will be absorbed more large education. Instead of two large spiral formations, a new elliptical galaxy will appear in the Universe. Until this time, our galaxy will be able to deal with its satellites. Two dwarf galaxies - the Large and Small Magellanic Clouds - will be absorbed by the Milky Way in 4 billion years.

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