We are used to the fact that the Milky Way is a cluster of stars in the sky, along which our ancestors were guided. But in fact, this is more than ordinary night lights - this is a huge and unexplored world.
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The structure of the Milky Way galaxy
It sometimes seems incredible how dynamically space science is developing. It is difficult to imagine, but 4 centuries ago, even the statement that the Earth revolves around the Sun caused condemnation and rejection in society. Judgments about these and other cosmic phenomena could lead not only to imprisonment, but also to death. Fortunately, times have changed, and the study of the Universe has long been a priority in science. Especially important in this regard are studies of the Milky Way - a galaxy of thousands of stars, one of which is our Sun.
Studying the structure of the galaxy and its development helps to answer the main questions that have been of interest to humanity since the beginning of time. These are such sacramental mysteries about how the solar system came into being, what factors contributed to the emergence of life on Earth, and whether life exists on other planets.
The fact that the Milky Way galaxy is a huge arm of an infinite star system became known relatively recently - just over half a century ago. The structure of our galaxy is similar to a colossal spiral in which our solar system is located somewhere on the periphery. From the side, it looks like a giant magnifying glass with a bilaterally convex center with a crown.
What is the Milky Way Galaxy? These are billions of stars and planets, which are interconnected by a certain algorithm for the structure of the Universe. In addition to stars, the Milky Way contains interstellar gas, galactic dust, and globular clusters.
The disk of our galaxy constantly revolves around the central part, which is located in the constellation Sagittarius. In order for the Milky Way to make one complete revolution around its axis, 220 million years are needed (and this despite the fact that the rotation occurs at a speed of 250 kilometers per second). Thus, all the stars of our galaxy have been moving in a single rush for many years and our solar system along with them. What makes them spin around the core at a truly breakneck speed? Scientists suggest that both the colossal weight of the center and an almost incomprehensible amount of energy (it can exceed the size of 150 million suns).
Why do we not see either spirals or a giant core, why do not we feel this universal rotation? The fact is that we are in the sleeve of this spiral Universe, and the frantic rhythm of its life is perceived by us everyday.
Of course, there will be skeptics who will deny such a structure of our galaxy, citing the fact that there is no exact picture of the galactic disk (and it cannot be). The fact is that the Universe is by no means limited to the Milky Way galaxy and in space there are a lot of the same formations. They are very similar to our galaxy in structure - these are the same disks with a center around which the stars revolve. That is, beyond our Milky Way, there are billions of systems similar to the Sun.
The nearest galaxy to us is the Large and Small Magellanic Clouds. They can be seen almost with the naked eye in the Southern Hemisphere. These two small luminous points, similar to clouds, were first described by the great traveler, from whose name the names of space objects originated. The diameter of the Magellanic Clouds is relatively small - less than half of the Milky Way. And there are much fewer star systems in the Clouds.
The Andromeda Nebula is different. This is another spiral-shaped galaxy that is very similar in appearance and composition to the Milky Way. Its dimensions are striking - by the most conservative estimates, it is three times larger than our Path. And the number of such gigantic galaxies in the Universe has already exceeded a billion for a long time - this is only what we can see at this stage in the development of astronomy. It is quite possible that a few years later we will become aware of another, previously unnoticed galaxy.
Milky Way characteristics
As stated earlier, the Milky Way is a cluster of millions of stars with their own solar-like systems. How many planets exist in our galaxy is a real mystery, the solution of which has been struggling for more than one generation of astronomers. Although, to be honest, they are more concerned about another question - what is the probability that there is a star system within our galaxy, the characteristics of which are similar to ours? Scientists are especially interested in stars that have similar rotational speed and technical characteristics to the Sun, and also occupy our place on the scale of the galaxy. This is because on planets with the approximate age and conditions of our Earth, there is a high probability of the presence of intelligent life.
Unfortunately, attempts by scientists to find anything similar to the solar system in the arms of the galaxy were unsuccessful. And this is perhaps for the best. It remains to be seen who or what may be waiting for us in an unfamiliar constellation.
Black Hole - Planetary Killer or Galaxy Maker?
At the end of its life, the star sheds its gaseous envelope, and its core begins to shrink very quickly. Provided that the mass of the star is large enough (1.4 times the Sun), a Black Hole is formed in its place. It is an object with a critical speed that no object can overcome. As a result, what falls into the Black Hole disappears into it forever. That is, in fact, this space element is a one-way ticket. Any object that comes close enough to the Hole will disappear forever.
Sad, isn't it? But there is also a positive moment in the Black Hole - thanks to it, various space objects are gradually pulled up and new galaxies are formed. It turns out that the core of each of the known star systems is the Black Hole.
Why is our galaxy called the Milky Way?
Each nation has its own legends about how the visible part of the Milky Way was formed. For example, the ancient Greeks believed that it was formed from the spilled milk of the goddess Hera. But in Mesopotamia there was a legend about a river made from the same drink. Thus, many peoples associated a large cluster of stars with milk, which is why our galaxy got its name.
How many stars are there in the Milky Way?
It is rather difficult to accurately calculate the number of stars in our galaxy, because they say that there are more than 200 billion of them. As you understand, it is very problematic to study them all with the modern development of science, therefore scientists turn their attention only to the most interesting representatives of these space objects. Take at least the alpha star from the constellation Karina (Carina). This is a supergiant star that has long held the title of the biggest and brightest.
The Sun is also one of the stars of the Milky Way, which, however, does not have any outstanding characteristics. This is a small yellow dwarf, which became famous only for the fact that for millions of years it has been the source of life on our planet.
Astronomers around the world have long compiled lists of stars that are distinguished by their outstanding mass or brightness. But this does not mean at all that each of them received its own name. Usually, the names of the stars consist of letters, numbers and the names of the constellations to which they refer. So, the brightest star in the Milky Way is designated on astronomical maps as R136a1, and R136 is nothing more than the name of the nebula from which it comes. This star has an indescribable power that cannot be compared with anything. R136a1 shines 8.7 million times brighter than our Sun, and therefore it is very difficult to imagine at least some kind of life near it.
But the colossal power does not at all mean that the R136a1 has impressive dimensions. The list of the largest stars is headed by UY Shield, which is 1.7 thousand times the size of our star. That is, if instead of the Sun there was this star, then it would take all the place from the center of our system to Saturn.
Although these stars would not be as large and powerful, the total number of their mass does not compare with the mass of the Black hole, which is located in the center of the galaxy. It is her colossal energy that holds the Milky Way, forcing it to move in a specific order.
Our galaxy is not just a scattering of stars in the night sky. This is a huge system that consists of hundreds of billions of stars, among which there is our Sun.
The Milky Way Galaxy is very majestic, beautiful. This huge world is our Motherland, our solar system. All 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 across, and, as you know, one light year is equal to 9460730472580 km. Our solar system is located from the center of the galaxy at a distance of 27,000 light years, in one of the arms, which is called the arm of Orion.
Our solar system revolves around the center of the Milky Way galaxy. This happens in the same way as the Earth revolves around the Sun. The solar system completes a full revolution in 200 million years.
Deformation
The Milky Way Galaxy looks like a disc with a bulge in the center. He's not in perfect shape. On the one hand, there is a bend to the north of the center of the galaxy, and on the other, it goes down, then turns to the right. Outwardly, such a deformation is somewhat reminiscent of a wave. The disc 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 referred to as 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 pulling a rope 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 be swallowed up by the Magellanic Clouds, and after a while it will be swallowed up by Andromeda.
Halo
Wondering which galaxy is the Milky Way, scientists began studying it. They managed to find out that 90% of its mass consists of dark matter, which creates a mysterious halo. Everything that can be seen with 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 have drawn up various models that take into account the invisible part without it. After the experiments, the opinion was put forward that if there were no halo, the speed of movement of the planets and other elements of the Milky Way would be less than now. Because of this feature, it has been assumed that most of the components are composed of invisible mass or dark matter.
Number of stars
One of the most unique is the Milky Way galaxy. The structure of our galaxy is unusual, it contains more than 400 billion stars. About a fourth 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 various stars, and only a small part of the Earth is visible, about 3000. It is impossible to say exactly how many stars are in the Milky Way, so how the galaxy is constantly losing objects due to their transformation into supernovae.
Gases and dust
About 15% of the galaxy's constituent is dust and gases. Could it be because of them that our galaxy is called the Milky Way? Despite its enormous size, we can see about 6,000 light years ahead, while the galaxy is 120,000 light years across. It may be larger, but even the most powerful telescopes cannot see further. This is due to the accumulation of gas and dust.
The thickness of the dust does not allow visible light to pass through, but infrared light passes through it, and scientists can create maps of the starry sky.
What came before
According to scientists, our galaxy has not always been like this. The Milky Way emerged from the merger of several other galaxies. This giant conquered other planets, areas, which had a strong impact on size and shape. Even now, the planets are being captured by the Milky Way galaxy. An example of this are the objects of Canis Major, a dwarf galaxy located near our Milky Way. Dog stars are periodically added to our universe, and from ours they move to other galaxies, for example, there is an exchange of objects with the Sagittarius galaxy.
Milky Way View
Not a single scientist, 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. Due to this location, it is not possible to take pictures of the entire Milky Way. Therefore, any image of a galaxy is either images of other visible galaxies or someone's fantasy. And we can only guess how it really looks. There is even a possibility that we now know as much about it as the ancient people who considered 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 in the heart. It is estimated to be just over 22 million kilometers in size, and this is the hole itself.
All substances that try to get into the hole form a huge disk, almost 5 million times larger than our Sun. But even this pulling force does not prevent new stars from forming at the edge of the black hole.
Age
According to estimates of the composition of the Milky Way galaxy, it was possible to establish an estimated age - 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 arms appeared. It gradually changed, and only about ten billion years ago it began to look as it does now.
We are part of something more
All of the stars in the Milky Way galaxy are part of a larger galactic structure. We are part of the Virgo Supercluster. The nearest 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 covers a huge area. And this is only a small part of the stellar neighborhood.
The Virgo Supercluster contains more than a hundred cluster groups spread over 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 complete revolution in 1 year. Our Sun revolves in the Milky Way around the center of the galaxy. Our galaxy is moving in relation to a special radiation. The relic radiation is a convenient landmark that allows you to determine the speed of a 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 from its special appearance, reminiscent of spilled milk in the night sky. The name was given to her in ancient Rome. Then she was called "expensive milk". Until now, it is called the Milky Way, associating the name with the appearance of the white stripe in the night sky, with spilled milk.
The galaxy has been mentioned since the era of Aristotle, who said that the Milky Way is the place where the celestial spheres are in contact with the 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 neighbours
For some reason, many people think that the closest galaxy to the Milky Way is Andromeda. But this opinion is not entirely correct. The closest "neighbor" to us 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, the Big Dog is closer to us than to the black hole in 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. Unusual stars with a huge density class M were discovered in Pse.
According to the theory, the Milky Way absorbed Canis Major, along with all its stars, planets and other objects.
Collision of galaxies
Recently, more and more information has been encountered that the nearest 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 able to unite galaxies, and due to the expansion of the Universe, they must 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 the Milky Way.
Astronomer J. Dubinsky created the collision model presented in this video:
The collision will not lead to a global catastrophe. And after a few billion years, a new system will form, with the usual galactic forms.
Lost galaxies
Scientists have conducted a large-scale study of the starry sky, covering about an eighth of it. As a result of the 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 dark matter halo, rarefied gas and scanty stars, remnants of dwarf galaxies that were once swallowed up by the Milky Way. With a sufficient amount of data, scientists have managed to collect the "skeleton" of the dead galaxies. It's like in paleontology - it's hard to tell from a few bones what the creature looked like, but with enough data, you can assemble a skeleton and guess what the lizard was. So it is here: the information content of the images made it possible to recreate the eleven galaxies that were swallowed up by the Milky Way.
Scientists are confident that as they observe and evaluate the information received, 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 hyperspeed stars in our galaxy did not originate in it, but in the Large Magellanic Cloud. Theorists cannot explain many points regarding the existence of such stars. For example, it is impossible to say for sure why a large number of hyperspeed stars are concentrated in Sextant and in Leo. After revising the theory, scientists came to the conclusion that such a speed can develop only because of the impact on them of a black hole located in the center of the Milky Way.
Recently, more and more stars are being discovered that do not move from the center of our galaxy. After analyzing the trajectory of superfast stars, scientists managed 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 an aging star. During the expansion and transformation into a red giant, the star engulfed its planet. And another planet in the same system changed its orbit. Seeing this and assessing the state of our Sun, scientists have come to the conclusion that the same will happen with our star. In about five million years, it will turn into 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 giant black hole.
In the night sky, we can see the galactic arms. They look like white stripes, reminiscent of a milky road that is strewn with stars. These are the branches of the Milky Way. They are best seen in clear weather during the warm season, when there is the most cosmic dust and gases.
The following arms are distinguished in our galaxy:
- A branch of a square.
- Orion. Our solar system is located in this arm. This sleeve is our "room" in the "house".
- Carina-Sagittarius Sleeve.
- Branch of Perseus.
- Shield Branch of the Southern Cross.
It also contains a core, a gas ring, and 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 on a clear sky. In our "house" a variety of processes are constantly taking place: stars are born, they disintegrate, other galaxies are bombarded, dust, gases appear, stars change and go out, others flare up, they lead a round dance around ... And all this happens somewhere, far away in a universe about which we know so little. Who knows, maybe the time will come when people will be able to get to other arms and planets of our galaxy in a matter of minutes, travel to other universes.
The solar system is immersed in a huge star system - the Galaxy, numbering hundreds of billions of stars of various luminosities and colors (Stars in the section: "The life of stars"). Astronomers are well aware of the properties of various types of stars in the Galaxy. 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 have been investigated in the vicinity of the Sun, with the exception of very dwarf stars that emit very little light. Most of them are very faint red dwarfs - their masses are 3-10 times less than that of the Sun. Sun-like stars are very rare, only 6%. Many of our neighbors (72%) are grouped into multiple systems, where the components are linked to each other by gravity. Which of the hundreds of nearby stars can claim the title of the Sun's closest neighbor? Now it is considered a component of the famous triple system Alpha Centauri - the faint red dwarf Proxima. The distance to the proximal is 1.31 pc, and the light travels from it to us for 4.2 years. The statistics of the circumsolar population gives an idea of \u200b\u200bthe 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 in outer space is. In 1755, the German philosopher and naturalist Immanuel Kant suggested that stars form groups in space, just as planets make up the solar system. He called these groups "star islands". According to Kant, one of such countless islands is the Milky Way - a grandiose cluster of stars visible in the sky as a light hazy streak. In ancient Greek, the word "galacticos" means "milky", therefore the Milky Way and similar star systems are called galaxies.
The size and structure of our Galaxy
Based on the results of his calculations, Herschel made an attempt 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 - 200 units, if we take the distance to Sirius as a unit. On the modern distance scale, this corresponds to 7300X1700 light years. This estimate generally reflects correctly the structure of the Milky Way, although it is highly imprecise. The fact is that, in addition to stars, the Galaxy 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 could see all of its stars.
The true dimensions of the Galaxy were established only in the XX century. It turned out that it is a much flatter formation than previously thought. The galactic disk is over 100,000 light years in diameter and about 1,000 light years thick. 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 the terrestrial 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, the German astronomer Walter Baade noticed that the flat lenticular disk of this huge galaxy is immersed in a thinner spherical star cloud - a halo. Since the nebula is very similar to our Galaxy, he suggested that the Milky Way has a similar structure. The stars in the galactic disk were called population type I, and halo stars were called population type II.
As shown by modern studies, the two types of stellar population differ not only in spatial position, but also in the nature of movement, as well as in chemical composition. These features are primarily associated with the different origins of the disc 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 much 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's halo coincides with the center of the galactic disk. The halo consists mainly of very old, dim, low-mass stars. They are found both singly and in the form of globular clusters, which can include over a million stars. The age of the population of the spherical component of the Galaxy exceeds 12 billion years. It is usually taken for the age of the galaxy itself. A characteristic feature of halo stars is their extremely small proportion of heavy chemical elements. The stars that form globular clusters contain hundreds of times less metals than the Sun.
Spherical stars concentrate towards the center of the Galaxy. The central, densest part of the halo within a few thousand light years of the galactic center is called the "bulge" ("thickening"). Stars and star clusters in the halo move around the center of the Galaxy in very elongated orbits. Due to the fact that the rotation of individual stars is almost random, the halo as a whole rotates very slowly.
Galaxy Structure: Disk
Compared to the halo, the disk rotates noticeably faster. Its rotation speed is not the same at different distances from the center. It rapidly increases from zero in the center to 200-240 km / s at a distance of 2 thousand light years from it, then decreases slightly, increases again to approximately the same value, and then remains almost constant. The study of the peculiarities of the disk rotation made it possible to estimate its mass. It turned out that it is 150 billion times the mass of the Sun. The disk population is very different from the halo population. 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.
Gas in the disk of the Galaxy is also concentrated mainly near its plane. It is located unevenly, forming numerous gas clouds - giant, heterogeneous superclouds several thousand light-years in length to small clouds no larger than a parsec. The main chemical element in our Galaxy is hydrogen. It is approximately 1/4 helium. Compared to these two elements, the rest are present in very small quantities. On average, the chemical composition of stars and gas in the disk is almost the same as that of the Sun.
Galaxy Structure: Core
One of the most interesting regions of the Galaxy is considered to be its center, or core, located in the direction of the constellation Sagittarius. The visible radiation of the central regions of the Galaxy is completely hidden from us by powerful layers of absorbing matter. Therefore, they began to study it only after the creation of receivers for infrared and radio radiation, which is absorbed to a lesser extent. The central regions of the Galaxy are characterized by a strong concentration of stars: in each cubic parsec near the center there are many thousands of them. The distances between the 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 brightest stars in our sky.
In addition to a large number of stars in the central region of the Galaxy, a circumnuclear gaseous disk is observed, consisting mainly of molecular hydrogen. Its radius exceeds 1000 light years. Closer to the center, there are regions of ionized hydrogen and numerous sources of infrared radiation, indicating star formation taking place 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 is also the bright radio source Sagittarius A, the origin of which is associated with the activity of the nucleus.
The space that we are trying to study is a vast and endless space, in which there are tens, hundreds, thousands of trillions of stars, united in certain groups. Our Earth does not live on its own. We are part of the solar system, which is a small particle and part of the Milky Way, a larger cosmic entity.
Our Earth, like other planets of the Milky Way, our star called the Sun, like other stars of the Milky Way, move in the Universe in a certain order and occupy designated places. Let's try to understand in more detail what is the structure of the Milky Way, and what are the main features of our galaxy?
The origin of the Milky Way
Our galaxy has its own history, like other areas of outer space, and is the product of a catastrophe on a universal scale. The main theory of the origin of the Universe, which today dominates the scientific community, is the Big Bang. The model that perfectly characterizes the Big Bang theory is a nuclear chain reaction at the microscopic level. Initially, there was some kind of substance, which, due to certain reasons, in an instant began to move and exploded. It is not worth talking about the conditions that led to the onset of the explosive reaction. This is far from our understanding. Now formed 15 billion years ago as a result of the cataclysm, the Universe is a huge, endless polygon.
The primary products of the explosion were initially gas clusters and clouds. Later, under the influence of gravitational forces and other physical processes, the formation of larger objects of a universal scale took place. Everything happened very quickly in cosmic terms, over billions of years. First there was the formation of stars, which formed clusters and later merged into galaxies, the exact number of which is unknown. By its composition, galactic matter is hydrogen and helium atoms in the company of other elements, which are the building blocks for the formation of stars and other space objects.
It is not possible to say exactly where the Milky Way is located in the Universe, since the center of the universe is not known exactly.
Due to the similarity of the processes that formed the Universe, our galaxy is very similar in structure to many others. By its type, it is a typical spiral galaxy, a type of object that is widespread in the Universe in a huge variety. In terms of its size, the galaxy is in the golden mean - not small and not huge. Our galaxy has much more smaller neighbors in the stellar house than those who have colossal dimensions.
The age of all galaxies that exist in outer space is the same. Our galaxy is practically the same age as the Universe and is 14.5 billion years old. During this huge period of time, the structure of the Milky Way has repeatedly changed, and this is happening today, only imperceptibly, in comparison with the pace of life on earth.
A curious story with the name of our galaxy. Scientists believe the name Milky Way is legendary. This is an attempt to connect the location of the stars in our sky with the ancient Greek myth about the father of the gods Kronos, who devoured his own children. The last child, who faced the same sad fate, turned out to be thin and was given to the nurse for fattening. During feeding, a spray of milk fell into the sky, thus creating a milk path. Subsequently, scientists and astronomers of all times and peoples agreed that our galaxy is indeed very similar to the milk road.
The Milky Way is currently in the middle of its development cycle. In other words, the cosmic gas and matter for the formation of new stars are coming to an end. The stars that exist are still quite young. As in the story with the Sun, which may turn into a Red Giant in 6-7 billion years, our descendants will observe the transformation of other stars and the entire galaxy as a whole into a red sequence.
Our galaxy can also cease to exist as a result of the next universal cataclysm. Research topics in recent years are guided by the upcoming meeting of the Milky Way with our nearest neighbor, the Andromeda galaxy. Probably, the Milky Way after meeting with the Andromeda galaxy will disintegrate into several small galaxies. In any case, this will be the reason for the appearance of new stars and the reorganization of the space nearest to us. It remains only to guess what the fate of the Universe and our galaxy is in the distant future.
Astrophysical parameters of the Milky Way
In order to imagine what the Milky Way looks like on the scale of space, it is enough to look at the Universe itself and compare its individual parts. Our galaxy is part of a subgroup, which in turn is part of the Local Group, a larger entity. Here, our space metropolis is adjacent to the Andromeda and Triangle galaxies. The trinity is surrounded by more than 40 small galaxies. The local group is already part of an even larger formation and is part of the Virgo supercluster. Some argue that these are only rough guesses about where our galaxy is. The scale of the formations is so huge that it is almost impossible to imagine all this. Today we know the distance to the nearest neighboring galaxies. Other deep sky objects are out of sight. Only theoretically and mathematically their existence is allowed.
The location of the galaxy became known only thanks to rough calculations that determined the distance to the nearest neighbors. The satellites of the Milky Way are dwarf galaxies - the Small and Large Magellanic Clouds. In total, according to scientists, there are up to 14 satellite galaxies that make up the escort of the universal chariot called the Milky Way.
As for the observable world, today there is enough information about what our galaxy looks like. The existing model, and with it the map of the Milky Way, was compiled on the basis of mathematical calculations obtained as a result of astrophysical observations. Each cosmic body or fragment of the galaxy takes its place. It is, like in the Universe, only on a smaller scale. The astrophysical parameters of our space metropolis are interesting, and they are impressive.
Our galaxy is a spiral type with a bar, which is designated as SBbc on star maps. The diameter of the Milky Way's galactic disk is on the order of 50-90 thousand light years, or 30 thousand parsecs. For comparison, the radius of the Andromeda galaxy is 110 thousand light years on the scale of the Universe. One can only imagine how much larger our neighbor is than the Milky Way. The dimensions of the dwarf galaxies closest to the Milky Way are tens of times smaller than the parameters of our galaxy. Magellanic clouds are only 7-10 thousand light years in diameter. There are about 200-400 billion stars in this huge stellar cycle. These stars are clustered in clusters and nebulae. A significant part of it is the arms of the Milky Way, in one of which our solar system is located.
Everything else is dark matter, clouds of cosmic gas and bubbles that fill interstellar space. The closer to the center of the galaxy, the more stars, the closer outer space becomes. Our Sun is located in a region of space, consisting of smaller space objects located at a considerable distance from each other.
The mass of the Milky Way is 6x1042 kg, which is trillions of times the mass of our Sun. Almost all the stars inhabiting our star country are located in the plane of one disk, the thickness of which is, according to various estimates, 1000 light years. It is not possible to find out the exact mass of our galaxy, since most of the visible spectrum of stars is hidden from us by the arms of the Milky Way. In addition, the mass of dark matter that occupies vast interstellar space is unknown.
The distance from the Sun to the center of our galaxy is 27 thousand light years. Being at a relative periphery, the Sun is rapidly moving around the center of the galaxy, making a complete revolution in 240 million years.
The center of the galaxy has a diameter of 1000 parsecs and consists of a nucleus with an interesting sequence. The center of the core has the shape of a bulge in which the largest stars and a cluster of hot gases are concentrated. It is this region that emits a huge amount of energy, which collectively is more than the billions of stars that make up the galaxy emit. This part of the core is the most active and brightest part of the galaxy. There is a bar along the edges of the nucleus, which is the beginning of the arms of our galaxy. Such a bridge arises as a result of the colossal force of gravity caused by the rapid speed of rotation of the galaxy itself.
Considering the central part of the galaxy, the following fact looks paradoxical. For a long time, scientists could not understand what is in the center of the Milky Way. It turns out that in the very center of the stellar country called the Milky Way, there is a supermassive black hole with a diameter of about 140 km. It is there that most of the energy released by the galactic nucleus goes, it is in this bottomless abyss that stars dissolve and die. The presence of a black hole in the center of the Milky Way indicates that all the processes of formation in the Universe must end sometime. Matter will turn into antimatter and everything will happen again. How this monster will behave after millions and billions of years, the black abyss is silent, which indicates that the processes of absorption of matter are only gaining strength.
From the center, there are two main arms of the galaxy - the Shield of the Centaur and Perseus. These structural formations were named after the constellations located in the sky. In addition to the main arms, the galaxy is surrounded by 5 other small arms.
Near and distant future
The arms born by the core of the Milky Way unwind in a spiral, filling space with stars and cosmic material. An analogy with cosmic bodies that revolve around the Sun in our star system is appropriate here. A huge mass of stars, large and small, clusters and nebulae, space objects of various sizes and nature, revolve on a giant carousel. All of them create a wonderful picture of the starry sky, which a person has been looking at for more than one thousand years. Studying our galaxy, you should know that the stars in the galaxy live according to their own laws, being today in one of the arms of the galaxy, tomorrow they will begin their journey in the other direction, leaving one arm and flying to the other.
Earth in the Milky Way galaxy is far from the only planet suitable for life. It is just a particle of dust, the size of an atom, which is lost in the vast starry world of our galaxy. There can be a huge number of such planets, similar to Earth, in the galaxy. It is enough to imagine the number of stars that somehow have their own stellar planetary systems. Other life may be far away, on the very edge of the galaxy, tens of thousands of light years away, or, conversely, be present in neighboring regions that are hidden from us by the arms of the Milky Way.
The Milky Way is our home galaxy, which houses the solar system, which houses the planet Earth, where people live. It belongs to the barred spiral galaxies and is a member of the Local Group of Galaxies along with the Andromeda Galaxy, the Triangle Galaxy and 40 dwarf galaxies. The Milky Way is 100,000 light years across. There are about 200-400 billion stars in our galaxy. Our solar system is located on the outskirts of the galactic disk, in a relatively calm place that allowed life to originate on our planet. It is possible that not only we live in the Milky Way, but this remains to be seen. Although, in the ocean of the Universe, the entire history of mankind is nothing more than a barely noticeable ripple, it is very interesting for us to learn about the Milky Way and follow the development of events in our native galaxy.
The infinitely expanding one is home to a myriad of galaxies. Woven from dust and gas and filled with celestial bodies, these amazing space travelers collide with each other. This is due to gravitational attraction. Inch by inch, light year after light year, the space clock brings the inevitable closer. Massive structures, each containing hundreds of billions of stars, mix and ignite. And our galaxy is no exception. Astronomers recently discovered Antlia 2, a low-density but massive galaxy that revolves around like a ghost. Scientists believe Antlia 2 may help unravel the mysteries of dark matter.