Constellations in the Milky Way galaxy. Milky Way

The Milky Way is our home galaxy, which contains solar system, in which the planet Earth is located, on which people live. It belongs to barred spiral galaxies and is included in the Local Group of galaxies along with the Andromeda galaxy, the Triangulum galaxy and 40 dwarf galaxies. The diameter of the Milky Way is 100,000 light years. There are about 200-400 billion stars in our galaxy. Our solar system is located on the outskirts of the disk of the galaxy, in a relatively quiet place, which allowed the origin of life on our planet. We may not be the only ones living in the Milky Way, but that 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 own galaxy.

The results of a study by an international group of astronomers, in the journal Nature Astronomy, suggest that our home galaxy is not at all like a flat "pancake", as was previously believed. Closer to the edges, the galaxy becomes larger by a compressed or crumpled accordion. Scientists believe that this discovery will force us to reconsider our current star charts.

Our galaxy. Mysteries of the Milky Way

To some extent, we know more about distant star systems than we do about our own galaxy, the Milky Way. It is more difficult to study its structure than the structure of any other galaxies, because it has to be studied from the inside, and much is not so easy to see. Interstellar dust clouds absorb the light emitted by myriads of distant stars.

Only with the development of radio astronomy and the advent of infrared telescopes, scientists were able to understand how our galaxy works. But many details remain unclear to this day. Even the number of stars in the Milky Way is estimated quite roughly. The newest electronic directories give numbers from 100 to 300 billion stars.

Not so long ago, it was believed that our Galaxy has 4 large arms. But in 2008, astronomers at the University of Wisconsin published the results of processing some 800,000 infrared images taken by the Spitzer space telescope. Their analysis showed that the Milky Way has only two arms. As for the other arms, they are only narrow side branches. So, the Milky Way is a spiral galaxy with two arms. It should be noted that most spiral galaxies known to us also have only two arms.

“Thanks to the Spitzer telescope, we have the opportunity to rethink the structure of the Milky Way,” said astronomer Robert Benjamin of the University of Wisconsin, speaking at a conference of the American Astronomical Society. “We are refining our understanding of the Galaxy in the same way that the discoverers centuries ago, traveling through the globe, refined and rethought previous ideas about what the Earth looks like.

Since the early 1990s, infrared observations have been increasingly changing our knowledge of the structure of the Milky Way, because infrared telescopes make it possible to look through gas and dust clouds and see what is inaccessible to conventional telescopes.

2004 - the age of our galaxy was estimated at 13.6 billion years. It arose shortly after. Initially, it was a diffuse gas bubble containing mainly hydrogen and helium. Over time, it turned into a huge spiral galaxy in which we now live.

general characteristics

But how did the evolution of our galaxy proceed? How did it form - slowly or, on the contrary, very quickly? How was it saturated with heavy elements? How the shape of the Milky Way and its chemical composition? Detailed answers to these questions have yet to be given by scientists.

The length of our Galaxy is about 100,000 light years, and the average thickness of the galactic disk is about 3,000 light years (the thickness of its convex part - the bulge - reaches 16,000 light years). However, in 2008, Australian astronomer Brian Gensler, after analyzing the results of observations of pulsars, suggested that the galactic disk is probably twice as thick as is commonly believed.

Is our galaxy big or small by cosmic standards? For comparison: the extent of the Andromeda Nebula, the nearest large galaxy to us, is approximately 150,000 light-years.

In late 2008, researchers determined using radio astronomy that the Milky Way was spinning faster than previously thought. Judging by this indicator, its mass is approximately one and a half times higher than it was commonly believed. According to various estimates, it varies from 1.0 to 1.9 trillion solar masses. Again, for comparison: the mass of the Andromeda nebula is estimated at the least at 1.2 trillion solar masses.

The structure of galaxies

Black hole

So, the Milky Way is not inferior in size to the Andromeda Nebula. "We should no longer treat our galaxy as the little sister of the Andromeda Nebula," said astronomer Mark Reid of the Smithsonian Center for Astrophysics at Harvard University. At the same time, since the mass of our Galaxy is greater than expected, its attractive force is also higher, which means that the probability of its collision with other galaxies in our vicinity also increases.

Our Galaxy is surrounded by a globular halo, reaching 165,000 light-years across. Astronomers sometimes refer to the halo as the "galactic atmosphere." It contains approximately 150 globular clusters, as well as a small number of ancient stars. The rest of the halo space is filled with rarefied gas and dark matter. The mass of the latter is estimated at about a trillion solar masses.

The spiral arms of the Milky Way contain huge amounts of hydrogen. This is where stars continue to be born. Over time, young stars leave the arms of galaxies and "move" into the galactic disk. However, the most massive and brightest stars do not live long enough, therefore they do not have time to move away from their birthplace. It is no coincidence that the arms of our Galaxy glow so brightly. Most of the Milky Way is made up of small, not very massive stars.

The central part of the Milky Way is located in the constellation Sagittarius. This area is surrounded by dark gas and dust clouds, beyond which nothing can be seen. Only since the 1950s, using the means of radio astronomy, have scientists been able to gradually see what lurks there. A powerful radio source, called Sagittarius A, was discovered in this part of the Galaxy. As observations have shown, a mass is concentrated here that exceeds the mass of the Sun by several million times. The most acceptable explanation for this fact is only one: at the center of our Galaxy is located.

Now, for some reason, she has given herself a break and is not particularly active. The influx of matter here is very scarce. Maybe in time the black hole will have an appetite. Then it will again begin to absorb the veil of gas and dust surrounding it, and the Milky Way will add to the list of active galaxies. It is possible that before this, stars will begin to rapidly emerge in the center of the Galaxy. Similar processes are likely to be repeated regularly.

2010 - American astronomers using the Fermi Space Telescope, designed to observe sources of gamma radiation, discovered two mysterious structures in our Galaxy - two huge bubbles emitting gamma radiation. The diameter of each of them is on average 25,000 light years. They scatter from the center of the Galaxy in the northern and southern directions. May be, we are talking about the streams of particles that once emitted a black hole located in the middle of the Galaxy. Other researchers believe that we are talking about gas clouds that exploded during the birth of stars.

There are several dwarf galaxies around the Milky Way. The most famous of them are the Large and Small Magellanic Clouds, which are associated with milky way a kind of hydrogen bridge, a huge plume of gas that stretches behind these galaxies. It is called the Magellanic Stream. Its length is about 300,000 light years. Our Galaxy is constantly consuming the nearest dwarf galaxies, in particular the Sagitarius Galaxy, which is located at a distance of 50,000 light-years from the galactic center.

It remains to add that the Milky Way and the Andromeda Nebula are moving towards each other. Presumably in 3 billion years, both galaxies will merge together, forming a larger elliptical galaxy, which has already been called the Milky Honey.

Origin of the Milky Way

Andromeda's nebula

For a long time it was believed that the Milky Way formed gradually. 1962 - Olin Eggen, Donald Linden-Bell and Allan Sandage proposed a hypothesis that became known as the ELS model (it was named after the initial letters of their surnames). According to her, a homogeneous cloud of gas once slowly rotated in place of the Milky Way. It resembled a ball and reached a diameter of approximately 300,000 light years, and consisted mainly of hydrogen and helium. Under the influence of gravity, the protogalaxy contracted and became flat; at the same time, its rotation accelerated noticeably.

For almost two decades, this model suited scientists. But new observational results have shown that the Milky Way could not have arisen as theorists prescribed it.

According to this model, the halo is formed first, and then the galactic disk. But there are also very ancient stars in the disk, for example, the red giant Arcturus, whose age is more than 10 billion years, or numerous white dwarfs of the same age.

Both in the galactic disk and in the halo, globular clusters have been found that are younger than the ELS model allows. Obviously, they are absorbed by our later Galaxy.

Many stars in the halo rotate in a different direction than the Milky Way. Maybe they, too, were once outside the Galaxy, but then they were drawn into this "stellar whirlwind" - like a random swimmer in a whirlpool.

1978 - Leonard Searle and Robert Zinn proposed their own model for the formation of the Milky Way. It was designated as "Model SZ". Now the history of the Galaxy has become noticeably more complicated. Not so long ago, her youth, in the view of astronomers, was described as simply as in the opinion of physicists - a rectilinear translational motion. The mechanics of what was happening was clearly visible: there was a homogeneous cloud; it consisted only of evenly spread gas. Nothing by its presence complicated the calculations of theorists.

Now, instead of one huge cloud in the visions of scientists, several small, bizarrely scattered clouds appeared at once. Stars were visible among them; however, they were located only in the halo. Inside the halo, everything was seething: the clouds collided; gas masses were mixed and compacted. Over time, a galactic disk formed from this mixture. New stars began to appear in it. But this model was subsequently criticized.

It was impossible to understand what connected the halo and the galactic disk. This thickening disk and the sparse stellar envelope around it had little in common. Even after Searle and Zinn made their model, it turned out that the halo rotates too slowly to form a galactic disk from it. Judging by the distribution of chemical elements, the latter arose from protogalactic gas. Finally, the angular momentum of the disk turned out to be 10 times higher than that of the halo.

The whole secret is that both models contain a grain of truth. The trouble is that they are too simple and one-sided. Both of them now seem to be fragments of the same recipe by which the Milky Way was created. Eggen and his colleagues read a few lines from this recipe, Searle and Zinn a few others. Therefore, trying to re-imagine the history of our Galaxy, we now and then notice familiar lines that have already been read once.

Milky Way. computer model

So it all started soon after big bang. “Today, it is commonly believed that fluctuations in the density of dark matter gave rise to the first structures, the so-called dark halos. Thanks to the force of gravity, these structures did not fall apart, ”says German astronomer Andreas Burkert, author of a new model for the birth of the Galaxy.

Dark halos have become embryos - nuclei - of future galaxies. Around them, under the influence of gravity, gas accumulated. A homogeneous collapse occurred, as described by the ELS model. Already 500-1000 million years after the Big Bang, gas clusters surrounding dark halos became the "incubators" of stars. Small protogalaxies appeared here. In dense clouds of gas, the first globular clusters arose, because stars were born here hundreds of times more often than anywhere else. Protogalaxies collided and merged with each other - this is how large galaxies were formed, including our Milky Way. Today it is surrounded by dark matter and a halo of single stars and their globular clusters, these ruins of a universe that is over 12 billion years old.

There were many very massive stars in protogalaxies. In less than a few tens of millions of years, most of them exploded. These explosions enriched the gas clouds with heavy chemical elements. Therefore, in the galactic disk, not such stars were born as in the halo - they contained hundreds of times more metals. In addition, these explosions generated powerful galactic vortices that heated up the gas and swept it out of the protogalaxies. There was a separation of gas masses and dark matter. It was critical stage formation of galaxies, not previously taken into account in any model.

At the same time, dark halos collided with each other more and more often. Moreover, protogalaxies were stretched out or disintegrated. These catastrophes are reminiscent of the chains of stars preserved in the halo of the Milky Way from the time of "youth". By studying their location, it is possible to evaluate the events that took place in that era. Gradually, a vast sphere formed from these stars - the halo we see. As it cooled, gas clouds penetrated into it. Their angular momentum was preserved, so they did not shrink into a single point, but formed a rotating disk. All this happened over 12 billion years ago. The gas was now compressed as described in the ELS model.

At this time, the "bulge" of the Milky Way is also formed - its middle part, resembling an ellipsoid. The bulge is made up of very old stars. It probably arose during the merger of the largest protogalaxies, which held the gas clouds the longest. In the middle of it were neutron stars and tiny black holes - relics of exploded supernovae. They merged with each other, simultaneously absorbing gas flows. Perhaps this is how the huge black hole was born, which is now in the center of our galaxy.

The history of the Milky Way is much more chaotic than previously thought. Our own Galaxy, impressive even by cosmic standards, was formed after a series of impacts and mergers - after a series of cosmic catastrophes. Traces of those ancient events can still be found today.

So, for example, not all stars in the Milky Way revolve around the galactic center. Probably, over the billions of years of its existence, our Galaxy has "absorbed" many fellow travelers. Every tenth star in the galactic halo is less than 10 billion years old. By that time, the Milky Way had already formed. Perhaps these are the remains of once captured dwarf galaxies. A group of British scientists from the Astronomical Institute (Cambridge), led by Gerard Gilmour, calculated that the Milky Way could obviously absorb from 40 to 60 Carina-type dwarf galaxies.

In addition, the Milky Way attracts huge masses of gas towards itself. So, in 1958, Dutch astronomers noticed many small spots in the halo. In fact, they turned out to be gas clouds, which consisted mainly of hydrogen atoms and rushed towards the galactic disk.

Our Galaxy will not moderate its appetite in the future. Perhaps it will absorb the nearest dwarf galaxies - Fornax, Carina and, probably, Sextans, and then merge with the Andromeda Nebula. Around the Milky Way - this insatiable "star cannibal" - will become even more deserted.

The Milky Way Galaxy is very majestic, beautiful. This huge world is our homeland, 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 at a distance of 27,000 light years from the center of the galaxy, in one of the arms, which is called the Orion arm.

Our solar system revolves around the center of the Milky Way galaxy. This happens in the same way that the Earth revolves around the Sun. The solar system makes a complete revolution in 200 million years.

Deformation

The Milky Way galaxy looks like a disk with a bulge in the center. It's not in perfect shape. On one side 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 disk itself is warped. This is due to the presence of the Small and Large Magellanic Clouds nearby. They orbit 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 like a tug of war between galaxies, creating vibrations. The result is a deformation of the Milky Way galaxy. 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 some more time it will be swallowed up by Andromeda.

Halo

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

Numerous studies have confirmed that the Milky Way has a halo. The scientists compiled various models, which took into account the invisible part and without it. After the experiments, the opinion was put forward that if there were no halo, then the speed of the planets and other elements of the Milky Way would be less than now. Because of this feature, it was suggested that most of the components consist of an 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 has more than 400 billion stars. Approximately one fourth of them big 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 very different stars, and only a small part, about 3000, is visible from Earth. It is impossible to say exactly how many stars are in the Milky Way, because how 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 huge size, we can see about 6,000 light-years ahead, but the size of the galaxy is 120,000 light-years. Maybe it is more, but even the most powerful telescopes cannot see beyond this. 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 was before

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

view of the milky way

No scientist, astronomer can say for sure what our Milky Way looks like from above. This is due to the fact that the 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 a snapshot of other visible galaxies, or someone else's fantasy. And we can only guess what it actually looks like. 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 at the very heart. According to assumptions, its dimensions are a little more than 22 million kilometers, and this is the hole itself.

All the matter that tries to get into the hole forms a huge disk, almost 5 million times the size of our Sun. But even such a pulling force does not prevent new stars from forming at the edge of a black hole.

Age

According to 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 did it begin to look like 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 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 groups of clusters over 110 million light-years across. 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. CMB radiation is a convenient reference point that allows you to determine the speed of various matters in the Universe. Studies have shown that our galaxy rotates at a speed of 600 kilometers per second.

Name appearance

The galaxy got its name because of its special appearance, reminiscent of spilled milk in the night sky. The name was given to her in Ancient Rome. Then it was called "the road of milk." Until now, it is called that - the Milky Way, associating the name with appearance white streak in the night sky, with spilled milk.

Mentions have been found about the galaxy since the era of Aristotle, who said that the Milky Way is a place where celestial spheres contact with the earth. Until the moment when the telescope was created, no one added anything to this opinion. And only since 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, 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. Unusual stars with a huge density of class M were discovered in Pse.

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

Collision of galaxies

AT recent times Increasingly, there is information 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 move 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 shown in this video:

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

Dead galaxies

Scientists 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.

A telescope installed in Chile took a huge number of images that allowed scientists to assess the sky. Surrounding our galaxy, according to the images, are halos of dark matter, rarefied gas and few stars, remnants of dwarf galaxies that were once swallowed up by the Milky Way. With enough data, scientists 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 the skeleton and guess what the lizard was. 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 decayed galaxies that were “eaten” by the Milky Way.

We're under fire

According to scientists, the hypervelocity 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 exactly why a large number of hypervelocity stars are concentrated in Sextant and Leo. Revising the theory, scientists came to the conclusion that such a speed can only develop due to 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 ultrafast stars, scientists managed to find out that we are under attack from the Large Magellanic Cloud.

The 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 swallowed up its planet. And another planet in the same system changed its orbit. Seeing this and assessing the state of our Sun, scientists came to the conclusion that the same thing will happen to our luminary. 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 gigantic black hole.

We can see galactic arms in the night sky. 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.

Our galaxy has the following arms:

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

Also in the composition there is 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. A variety of processes are constantly taking place in our “house”: stars are born, decay, other galaxies are shelling us, dust and gases appear, stars change and go out, others flare up, they 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 reach other arms and planets of our galaxy in a matter of minutes, travel to other universes.

In our age, illuminated by hundreds electric lights, residents of the city do not have the opportunity to see the Milky Way. This is a phenomenon that occurs in our sky only in certain period years, are observed only far from large settlements. In our latitudes, it is especially beautiful in August. AT last month summer, the Milky Way rises above the Earth in the form of a giant celestial arch. This weak, blurred strip of light looks denser and brighter in the direction of Scorpio and Sagittarius, and paler and more diffuse - near Perseus.

star riddle

The Milky Way is an unusual phenomenon, the secret of which has not been revealed to people for a whole string of centuries. In the legends and myths of many peoples, it was called differently. The amazing glow was the mysterious Star Bridge leading to paradise, the Road of the Gods and the magical Heavenly River carrying divine milk. At the same time, all peoples believed that the Milky Way is something sacred. The radiance was worshipped. Temples were built in honor of him.

Few people know that our Christmas tree is an echo of the cults of people who lived in the old days. Indeed, in ancient times it was believed that the Milky Way is the axis of the Universe or the World Tree, on the branches of which stars ripen. That is why at the beginning annual cycle and decorate the tree. The earthly tree was an imitation of the eternally fruitful tree of heaven. Such a ritual gave hope for the favor of the gods and good harvest. So great was the significance of the Milky Way for our ancestors.

scientific assumptions

What is the Milky Way? The history of the discovery of this phenomenon has almost 2000 years. Even Plato called this strip of light a seam connecting the celestial hemispheres. In contrast, Anaxagoras and Demoxides argued that the Milky Way (which color, we will consider) is a kind of illumination of the stars. She is the decoration of the night sky. Aristotle explained that the Milky Way is a radiance in the air of our planet of luminous circumlunar vapors.

There were many other speculations as well. So, the Roman Mark Manilius said that the Milky Way is a constellation of small celestial bodies. It was he who was closest to the truth, but he could not confirm his assumptions in those days when the sky was observed only with the naked eye. All ancient researchers believed that the Milky Way is part of the solar system.

Discovery of Galileo

The Milky Way revealed its secret only in 1610. It was then that the first telescope was invented, which was used by Galileo Galilei. The famous scientist saw through the device that the Milky Way is a real cluster of stars, which, when viewed with the naked eye, merged into a continuous faintly flickering band. Galileo even succeeded in explaining the heterogeneity of the structure of this band.

It was caused by the presence in the celestial phenomenon of not only star clusters. There are also dark clouds. The combination of these two elements creates amazing image nocturnal event.

Discovery of William Herschel

The study of the Milky Way continued into the 18th century. During this period, his most active researcher was William Herschel. The famous composer and musician was engaged in the manufacture of telescopes and studied the science of the stars. The most important discovery of Herschel was the Great Plan of the Universe. This scientist observed the planets through a telescope and counted them in different parts of the sky. Studies have led to the conclusion that the Milky Way is a kind of stellar island, in which our Sun is also located. Herschel even drew a schematic plan of his discovery. In the figure, the star system was depicted as a millstone and had an elongated irregular shape. The sun at the same time was inside this ring that surrounded our world. This is how all scientists represented our Galaxy until the beginning of the last century.

It was not until the 1920s that the work of Jacobus Kaptein saw the light of day, in which the Milky Way was described in the most detailed way. At the same time, the author gave a scheme of the star island, which is as similar as possible to the one that is known to us at the present time. Today we know that the Milky Way is a Galaxy, which includes the solar system, the Earth and those individual stars that are visible to humans with the naked eye.

The structure of galaxies

With the development of science, astronomical telescopes became more powerful and more powerful. At the same time, the structure of the observed galaxies became clearer. It turns out they don't look alike. Some of them were wrong. Their structure was not symmetrical.

Elliptical and spiral galaxies have also been observed. To which of these types does the Milky Way belong? This is our Galaxy, and being inside, it is very difficult to determine its structure. However, scientists have found the answer to this question. Now we know what the Milky Way is. Its definition was given by researchers who found that it is a disk that has an inner core.

general characteristics

The Milky Way is a spiral galaxy. At the same time, it has a jumper in the form of a huge interconnected by gravitational forces.

The Milky Way is believed to have been in existence for over thirteen billion years. This is the period during which about 400 billion constellations and stars, more than a thousand huge gas nebulae, clusters and clouds formed in this Galaxy.

The shape of the Milky Way is clearly visible on the map of the Universe. Upon examination, it becomes clear that this cluster of stars is a disk with a diameter of 100 thousand light years (one such light year is ten trillion kilometers). Thickness - 15 thousand, and depth - about 8 thousand light years.

How much does the Milky Way weigh? This (the definition of its mass is very difficult task) cannot be calculated. It is difficult to determine the mass of dark matter that does not interact with electromagnetic radiation. That is why astronomers cannot definitively answer this question. But there are rough estimates, according to which the weight of the Galaxy is in the range from 500 to 3000 billion solar masses.

The Milky Way is like all celestial bodies. It makes revolutions around its axis, moving in the Universe. Astronomers point to the uneven, even chaotic movement of our Galaxy. This is explained by the fact that each of its constituent star systems and nebulae has its own speed, different from others, as well as different forms and types of orbits.

What are the parts of the Milky Way? These are the core and bridges, the disk and spiral arms, as well as the crown. Let's consider them in more detail.

Nucleus

This part of the Milky Way is located in the core. There is a source of non-thermal radiation with a temperature of about ten million degrees. In the center of this part of the Milky Way is a seal called the "bulge". This is a whole string of old stars that moves in an elongated orbit. Most of these celestial bodies life cycle is already coming to an end.

In the central part of the core of the Milky Way is located This section of outer space, the weight of which is equal to the mass of three million suns, has a powerful gravity. Another black hole revolves around it, only smaller. Such a system creates something so strong that nearby constellations and stars move along very unusual trajectories.

The center of the Milky Way has other features as well. So, it is characterized by a large cluster of stars. Moreover, the distance between them is hundreds of times less than that observed on the periphery of the formation.

It is also interesting that, when observing the nuclei of other galaxies, astronomers note their bright radiance. But why is it not visible in the Milky Way? Some researchers have even suggested that there is no nucleus in our Galaxy. However, it has been determined that dark layers exist in spiral nebulae, which are interstellar accumulations of dust and gas. They also exist in the Milky Way. These huge dark clouds do not allow the earthly observer to see the radiance of the core. If such a formation did not interfere with earthlings, then we could observe the core in the form of a shining ellipsoid, the size of which would exceed the diameter of a hundred moons.

Modern telescopes, which are capable of operating in special ranges of the electromagnetic radiation spectrum, helped people answer this question. With this state-of-the-art technology that was able to bypass the dust shield, scientists were able to see the core of the Milky Way.

Jumper

This element of the Milky Way crosses its central section and has a size of 27 thousand light years. The jumper consists of 22 million red stars with an impressive age. Around this formation is a gas ring, which contains a large percentage of molecular oxygen. All this suggests that the Milky Way bar is the area where most stars are formed.

Disk

This is the shape of the Milky Way itself, which is in constant rotation. Interestingly, the speed this process depends on the distance of one or another region from the nucleus. So, in the very center it is equal to zero. At a distance of two thousand light years from the core, the rotation speed is 250 kilometers per hour.

Surrounding the outer side of the Milky Way is a layer of atomic hydrogen. Its thickness is 1.5 thousand light years.

On the outskirts of the Galaxy, astronomers have discovered the presence of dense accumulations of gas with a temperature of 10 thousand degrees. The thickness of such formations is several thousand light years.

Five spiral arms

This is another component of the Milky Way, located directly behind the gas ring. Spiral arms cross the constellations Cygnus and Perseus, Orion and Sagittarius, and Centaurus. These formations are unevenly filled with molecular gas. Such a composition introduces errors into the rules for the rotation of the Galaxy.
Spiral arms emerge directly from the core of the stellar island. We observe them with the naked eye, calling the bright band the Milky Way.

Spiral branches are projected onto each other, which makes it difficult to understand their structure. Scientists suggest that such arms were formed due to the presence in the Milky Way of giant waves of rarefaction and compression of interstellar gas, which move from the core to the galactic disk.

Crown

The Milky Way has a spherical halo. This is his crown. This formation consists of individual stars and clusters of constellations. Moreover, the dimensions of the spherical halo are such that it goes beyond the boundaries of the Galaxy by 50 light years.

As a rule, the Milky Way's corona contains low-mass and old stars, as well as dwarf galaxies and accumulations of hot gas. All these components produce movement in elongated orbits around the nucleus, making random rotation.

There is a hypothesis according to which the appearance of the corona was the result of the absorption of small galaxies by the Milky Way. According to astronomers, the age of the halo is about twelve billion years.

The location of the stars

On a cloudless night sky, the Milky Way is visible from anywhere on our planet. However, only a part of the Galaxy, which is a system of stars located inside the Orion arm, is accessible to the human eye.

What is the Milky Way? The definition in space of all its parts becomes most understandable if we consider the star map. In this case, it becomes clear that the Sun, illuminating the Earth, is located almost on the disk. This is almost the edge of the Galaxy, where the distance from the nucleus is 26-28 thousand light years. Moving at a speed of 240 kilometers per hour, the Luminary spends 200 million years on one revolution around the core, so that for the entire time of its existence it traveled across the disk, rounding the core, only thirty times.

Our planet is in the so-called corotation circle. This is a place in which the speed of rotation of the arms and stars are identical. This circle is characterized by an increased level of radiation. That is why life, as scientists believe, could only arise on that planet, near which there is a small number of stars.

Our Earth is such a planet. It is located on the periphery of the Galaxy, in its most peaceful place. That is why on our planet for several billion years there were no global cataclysms that often occur in the Universe.

Forecast for the future

Scientists suggest that in the future, collisions between the Milky Way and other galaxies are very likely, the largest of which is the Andromeda galaxy. But at the same time, it is not possible to talk specifically about anything. This requires knowledge of the transverse velocities of extragalactic objects, which are not yet available to modern researchers.

In September 2014, one of the models for the development of events was published in the media. According to her, four billion years will pass, and the Milky Way will absorb the Magellanic clouds (Large and Small), and in another billion years it will itself become part of the Andromeda Nebula.

Divide by social groups, our Milky Way galaxy will belong to a strong "middle class". So, it belongs to the most common type of galaxy, but at the same time it is not average in size or mass. There are more galaxies that are smaller than the Milky Way than those that are larger than it. Our "star island" also has at least 14 satellites - other dwarf galaxies. They are doomed to circle the Milky Way until they are consumed by it, or fly away from an intergalactic collision. Well, so far this is the only place where life certainly exists - that is, we are with you.

But still the Milky Way remains the most mysterious galaxy in the Universe: being on the very edge of the "star island", we see only a part of its billions of stars. And the galaxy is completely invisible - it is covered with dense sleeves of stars, gas and dust. The facts and secrets of the Milky Way will be discussed today.