2 why our galaxy is called the milky way. Some interesting facts about our Galaxy - the Milky Way

The starry sky has attracted people's gaze since ancient times. The best minds of all nations tried to comprehend our place in the Universe, imagine and justify its structure. Scientific progress has made it possible to move in the study of the vast expanses of space from romantic and religious constructions to logically verified theories based on numerous factual materials. Now any schoolchild has an idea of ​​what our Galaxy looks like according to the latest research, who, why and when gave it such a poetic name and what its expected future is.

origin of name

The expression “Milky Way Galaxy” is essentially a tautology. Galactikos roughly translated from ancient Greek means “milk”. This is what the inhabitants of the Peloponnese called the cluster of stars in the night sky, attributing its origin to the hot-tempered Hera: the goddess did not want to feed Hercules, the illegitimate son of Zeus, and in anger splashed breast milk. The drops formed a star trail, visible on clear nights. Centuries later, scientists discovered that the observed luminaries are only an insignificant part of existing celestial bodies. They gave the name Galaxy or the Milky Way system to the space of the Universe in which our planet is located. After confirming the assumption of the existence of other similar formations in space, the first term became universal for them.

A look from the inside

Scientific knowledge about the structure of the part of the Universe, including the Solar System, learned little from the ancient Greeks. Understanding of what our Galaxy looks like has evolved from Aristotle's spherical universe to modern theories that include black holes and dark matter.

The fact that Earth is part of the Milky Way system imposes certain limitations on those trying to figure out what shape our Galaxy has. To answer this question unambiguously, a view from the outside is required, and at a great distance from the object of observation. Now science is deprived of such an opportunity. A kind of substitute for an outside observer is the collection of data on the structure of the Galaxy and its correlation with the parameters of other space systems available for study.

The information collected allows us to say with confidence that our Galaxy has the shape of a disk with a thickening (bulge) in the middle and spiral arms diverging from the center. The latter contain the brightest stars in the system. The diameter of the disk is more than 100 thousand light years.

Structure

The center of the Galaxy is hidden by interstellar dust, making it difficult to study the system. Radio astronomy methods help to cope with the problem. Waves of a certain length easily overcome any obstacles and allow you to obtain the much desired image. Our Galaxy, according to the data obtained, has an inhomogeneous structure.

Conventionally, we can distinguish two elements connected with each other: the halo and the disk itself. The first subsystem has the following characteristics:

• the shape is a sphere;

• its center is considered to be a bulge;
• the highest concentration of stars in the halo is characteristic of its middle part; as you approach the edges, the density decreases greatly;
• The rotation of this zone of the galaxy is quite slow;
• the halo mainly contains old stars with relatively low mass;
• a significant space of the subsystem is filled with dark matter.

The density of stars in the galactic disk greatly exceeds the halo. In the sleeves there are young and even just emerging

Center and core

The “heart” of the Milky Way is located in Without studying it, it is difficult to fully understand what our Galaxy is like. The name "core" in scientific writings either refers only to the central region, only a few parsecs in diameter, or includes the bulge and gas ring, considered the birthplace of stars. In what follows, the first version of the term will be used.

Visible light has difficulty penetrating the center of the Milky Way because it encounters a lot of cosmic dust, hiding what our Galaxy looks like. Photos and images taken in the infrared range significantly expand astronomers' knowledge of the nucleus.

Data on the characteristics of radiation in the central part of the Galaxy led scientists to believe that there is a black hole at the core of the nucleus. Its mass is more than 2.5 million times the mass of the Sun. Around this object, according to researchers, another, but less impressive in its parameters, black hole rotates. Modern knowledge about the structural features of space suggests that such objects are located in the central part of most galaxies.

Light and darkness

The combined influence of black holes on the motion of stars makes its own adjustments to the way our Galaxy looks: it leads to specific changes in orbits that are not typical for cosmic bodies, for example, near the Solar system. The study of these trajectories and the relationship between the speed of movement and the distance from the center of the Galaxy formed the basis of the now actively developing theory of dark matter. Its nature is still shrouded in mystery. The presence of dark matter, which presumably makes up the vast majority of all matter in the Universe, is registered only by the effect of gravity on orbits.

If we dispel all the cosmic dust that hides the core from us, an amazing picture will be revealed. Despite the concentration of dark matter, this part of the Universe is full of light emitted by a huge number of stars. There are hundreds of times more of them per unit of space here than near the Sun. About ten billion of them form a galactic bar, also called a bar, of an unusual shape.

Space nut

Studying the center of the system in the long-wavelength range allowed us to obtain a detailed infrared image. Our Galaxy, as it turns out, has a structure at its core that resembles a peanut in a shell. This “nut” is the bridge, which includes more than 20 million red giants (bright, but less hot stars).

The spiral arms of the Milky Way radiate from the ends of the bar.

The work associated with the discovery of the “peanut” at the center of the star system not only shed light on the structure of our Galaxy, but also helped to understand how it developed. Initially, in the space of space there was an ordinary disk, in which a jumper formed over time. Under the influence of internal processes, the bar changed its shape and began to resemble a nut.

Our home on the space map

The activity occurs both in the bar and in the spiral arms that our Galaxy possesses. They were named after the constellations where sections of the branches were discovered: the arms of Perseus, Cygnus, Centaurus, Sagittarius and Orion. Near the latter (at a distance of at least 28 thousand light years from the core) is the Solar System. This area has certain characteristics that, according to experts, made possible the emergence of life on Earth.

The galaxy and our solar system rotate along with it. The patterns of movement of individual components do not coincide. stars are sometimes included in the spiral branches, sometimes separated from them. Only luminaries lying on the boundary of the corotation circle do not make such “travels”. These include the Sun, protected from powerful processes constantly occurring in the arms. Even a slight shift would negate all other benefits for the development of organisms on our planet.

The sky is in diamonds

The Sun is just one of many similar bodies that our Galaxy is full of. The total number of stars, single or grouped, according to the latest data, exceeds 400 billion. The closest to us, Proxima Centauri, is part of a system of three stars, along with the slightly more distant Alpha Centauri A and Alpha Centauri B. The brightest point of the night sky, Sirius A, is located in Its luminosity, according to various sources, exceeds the solar one by 17-23 times. Sirius is also not alone; he is accompanied by a satellite bearing a similar name, but marked B.

Children often begin to get acquainted with what our Galaxy looks like by searching the sky for the North Star or Alpha Ursa Minor. It owes its popularity to its position above the North Pole of the Earth. In terms of luminosity, Polaris is significantly higher than Sirius (almost two thousand times brighter than the Sun), but it cannot challenge Alpha Canis Majoris for the title of the brightest due to its distance from Earth (estimated from 300 to 465 light years).

Types of luminaries

Stars differ not only in luminosity and distance from the observer. Each is assigned a certain value (the corresponding parameter of the Sun is taken as a unit), the degree of surface heating, and color.

Supergiants have the most impressive sizes. Neutron stars have the highest concentration of matter per unit volume. The color characteristic is inextricably linked with temperature:

• reds are the coldest;
• heating the surface to 6,000º, like the Sun, gives rise to a yellow tint;
• white and blue luminaries have a temperature of more than 10,000º.

May vary and reach a maximum shortly before its collapse. Supernova explosions make a huge contribution to understanding what our Galaxy looks like. Photos of this process taken by telescopes are amazing.
The data collected on their basis helped to reconstruct the process that led to the outbreak and predict the fate of a number of cosmic bodies.

The future of the Milky Way

Our Galaxy and other galaxies are constantly in motion and interacting. Astronomers have found that the Milky Way has repeatedly absorbed its neighbors. Similar processes are expected in the future. Over time, it will include the Magellanic Cloud and a number of other dwarf systems. The most impressive event is expected in 3-5 billion years. This will be a collision with the only neighbor that is visible from Earth with the naked eye. As a result, the Milky Way will become an elliptical galaxy.

The endless expanses of space amaze the imagination. It is difficult for the average person to realize the scale of not only the Milky Way or the entire Universe, but even the Earth. However, thanks to the achievements of science, we can imagine at least approximately what kind of grandiose world we are part of.

Hello, dear guys! And greetings to you, dear parents! I invite you to go on a small journey into the cosmic world, full of the unknown and enchanting.

How often do we look into a dark sky full of bright stars, trying to find the constellations discovered by astronomers. Have you ever seen the Milky Way in the sky? Let's take a closer look at this unique cosmic phenomenon. And at the same time we will get information for an educational and interesting “space” project.

Lesson plan:

Why is it called that?

This star trail in the sky looks like a white stripe. Ancient people explained this phenomenon seen in the starry night sky with the help of mythological stories. Different peoples had their own versions of the appearance of an unusual sky strip.

The most widespread hypothesis is that of the ancient Greeks, according to which the Milky Way is nothing more than the spilled mother’s milk of the Greek goddess Hera. Likewise, explanatory dictionaries interpret the adjective “milky” as “reminiscent of milk.”

There’s even a song about it, you’ve probably heard it at least once. And if not, then listen right now.

Because of the way the Milky Way looks, it has several names:

• the Chinese call it the “yellow road”, believing that it looks more like straw;
• The Buryats call the star stripe the “seam of the sky” from which the stars scattered;
• among the Hungarians it is associated with the road of warriors;
• ancient Indians considered it the milk of the evening red cow.

How to see the “milk track”?

Of course, this is not milk that someone spills across the night sky every day. The Milky Way is a giant star system called a “Galaxy”. In appearance, it looks like a spiral, in the center of which there is a core, and arms extend from it like rays, of which the Galaxy has four.

How to find this white path of stars? You can even see a star cluster with the naked eye in the night sky when there are no clouds. All inhabitants of the Milky Way are located on the same line.

If you are a resident of the northern hemisphere, then you can find a place where there is a scattering of stars at midnight in July. In August, when it gets dark earlier, it will be possible to search for the spiral of the Galaxy starting at ten in the evening, and in September - after 20.00. You can see all the beauty by first finding the constellation Cygnus and moving from it with your gaze to the north - northeast.

To see the brightest stellar segments, you need to go to the equator, or even better, closer to 20-40 degrees south latitude. It is there that at the end of April - beginning of May the Southern Cross and Sirius flaunt in the night sky, between which the treasured galactic star path passes.

When the constellations Sagittarius and Scorpio rise in the eastern part by June-July, the Milky Way gains particular brightness, and clouds of cosmic dust can even be seen between distant stars.

Seeing various photographs, many wonder: why do we see not a spiral, but only a stripe? The answer to this question is very simple: we are inside the Galaxy! If we stand in the center of a sports hoop and raise it at eye level, what will we see? That's right: a stripe in front of your eyes!

The galactic core can be found in the constellation Sagittarius using radio telescopes. But you shouldn’t expect much brightness from it. The central part is the darkest due to the large amount of cosmic dust in it.

What is the Milky Way made of?

Our Galaxy is just one of millions of star systems that have been found by astronomers, but it is quite a large one. The Milky Way has approximately 300 billion stars. The Sun, which rises every day in the sky, is also part of them, revolving around the core. The Galaxy has stars much larger and brighter than the Sun, and there are smaller ones that emit faint light.

They differ not only in size, but also in color - they can be white-blue (they are the hottest) and red (the coldest). They all move together in a circle along with the planets. Just imagine that we go through a full revolution around the galactic circle in almost 250 million years - that’s how long one galactic year lasts.

Stars live in the strip of the Milky Way, forming groups that scientists call clusters, differing in age and stellar composition.

1. Small open clusters are the youngest, they are only about 10 million years old, but this is where the massive and bright celestial representatives live. Such groups of stars are located along the edge of the plane.
2. Globular clusters are very old, they were formed over 10 - 15 billion years, they are located in the center.

10 interesting facts

As always, I advise you to decorate your research work with the most interesting “galactic” facts. Watch the video carefully and be surprised!

This is our Galaxy, in which we live among wonderful, bright neighbors. If you are not yet personally familiar with the “milk path,” then quickly go outside to see all the starry beauty in the night sky.

By the way, have you already read the article about our cosmic neighbor the Moon? Not yet? Then take a look here soon)

Good luck in your studies!

Evgenia Klimkovich.

The Milky Way Galaxy is very majestic and beautiful. This huge world is 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. It's not the 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 seem to be in 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 have compiled various models that take 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 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, so how the galaxy is constantly losing objects due to them going supernova.

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.

The thickness of the dust does not allow visible light to pass through, but infrared light passes through, 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 the objects of 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.” To this day it is called the Milky Way, associating the name with the appearance of a white stripe in 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 the place where the celestial spheres contact the terrestrial 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. 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. Unusual stars with enormous class M densities were discovered in Canis.

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

Collision of galaxies

Recently, information has become increasingly common 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 the 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, a new system will be formed, with the usual galactic forms.

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 assemble 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 a large number of hypervelocity stars are concentrated 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, 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 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.

The science

Each person has his own idea of ​​what home is. For some it's a roof over their head, for others a home is... planet Earth, a rocky ball that plows through outer space along its closed path around the Sun.

No matter how big our planet may seem to us, it is just a grain of sand in giant star system, the size of which is difficult to imagine. This star system is the Milky Way galaxy, which can also rightfully be called our home.

Galaxy Sleeves

Milky Way- a spiral galaxy with a bar that runs through the center of the spiral. About two-thirds of all known galaxies are spiral, and two-thirds of them are barred. That is, the Milky Way is included in the list most common galaxies.

Spiral galaxies have arms that extend out from the center, like wheel spokes that twist in a spiral. Our solar system is located in the central part of one of the arms, which is called Orion's sleeve.

The Orion Arm was once thought to be a small "offshoot" of larger arms such as Perseus arm or Shield-Centauri arm. Not long ago, it was suggested that the Orion arm is indeed branch of the Perseus arm and does not leave the center of the galaxy.

The problem is that we cannot see our galaxy from the outside. We can only observe those things that are around us, and judge what shape the galaxy has, being, as it were, inside it. However, scientists were able to calculate that this sleeve has a length of approximately 11 thousand light years and thickness 3500 light years.

Supermassive black hole

The smallest supermassive black holes that scientists have discovered are approximately V 200 thousand times heavier than the sun. For comparison: ordinary black holes have the mass of just 10 times exceeding the mass of the Sun. At the center of the Milky Way is an incredibly massive black hole, the mass of which is difficult to imagine.

For the past 10 years, astronomers have been monitoring the activity of stars in orbit around the star. Sagittarius A, a dense region at the center of the spiral of our galaxy. Based on the movement of these stars, it was determined that in the center Sagittarius A*, which is hidden behind a dense cloud of dust and gas, there is a supermassive black hole whose mass 4.1 million times more than the mass of the Sun!

The animation below shows the actual motion of stars around a black hole. from 1997 to 2011 in the region of one cubic parsec in the center of our galaxy. When stars approach a black hole, they loop around it at incredible speeds. For example, one of these stars, S 0-2 moves at speed 18 million kilometers per hour: black hole first attracts her, and then sharply pushes her away.

Just recently, scientists observed how a cloud of gas approached a black hole and was torn to pieces by its massive gravitational field. Parts of this cloud were swallowed up by the hole, and the remaining parts began to resemble long thin noodles longer than 160 billion kilometers.

Magneticparticles

In addition to the presence of a supermassive all-consuming black hole, the center of our galaxy boasts incredible activity: old stars die, and new ones are born with enviable consistency.

Not long ago, scientists noticed something else at the galactic center - a stream of high-energy particles that extend a distance 15 thousand parsecs across the galaxy. This distance is approximately half the diameter of the Milky Way.

The particles are invisible to the naked eye, but magnetic imaging shows that particle geysers occupy approx. two thirds of the visible sky:

What is behind this phenomenon? For one million years, stars appeared and disappeared, feeding never stopping flow, directed towards the outer arms of the galaxy. The total energy of the geyser is a million times greater than the energy of a supernova.

Particles move at incredible speeds. Based on the structure of the particle flow, astronomers built magnetic field model, which dominates our galaxy.

Newstars

How often do new stars form in our galaxy? Researchers have been asking this question for many years. It was possible to map the areas of our galaxy where there is aluminum-26, an isotope of aluminum that appears where stars are born or die. Thus, it was possible to find out that every year in the Milky Way galaxy 7 new stars and approximately twice in a hundred years a large star explodes in a supernova.

The Milky Way Galaxy does not produce the largest number of stars. When a star dies, it releases such raw materials into space as like hydrogen and helium. Over hundreds of thousands of years, these particles coalesce into molecular clouds that eventually become so dense that their center collapses under their own gravity, thus forming a new star.

It looks like a kind of eco-system: death feeds new life. Particles from a particular star will be part of a billion new stars in the future. This is how things are in our galaxy, which is why it is evolving. This leads to the formation of new conditions under which the likelihood of the emergence of Earth-like planets increases.

Planets of the Milky Way galaxy

Despite the constant death and birth of new stars in our galaxy, their number has been calculated: the Milky Way is home to approximately 100 billion stars. Based on new research, scientists suggest that every star is orbited by at least one planet or more. That is, in our corner of the Universe there is only from 100 to 200 billion planets.

The scientists who came to this conclusion studied stars like red dwarfs of spectral type M. These stars are smaller than our Sun. They make up 75 percent of all the stars in the Milky Way. In particular, researchers paid attention to the star Kepler-32, which sheltered five planets.

How do astronomers discover new planets?

Planets, unlike stars, are difficult to detect because they do not emit their own light. We can say with certainty that there is a planet around a star only when it stands in front of his star and blocks out its light.

The planets of Kepler -32 behave exactly like exoplanets orbiting other M dwarf stars. They are located approximately at the same distance and have similar sizes. That is, the Kepler -32 system is typical system for our galaxy.

If there are more than 100 billion planets in our galaxy, how many of them are Earth-like planets? It turns out, not so much. There are dozens of different types of planets: gas giants, pulsar planets, brown dwarfs, and planets where molten metal rains from the sky. Those planets that consist of rocks can be located too far or too close to the star, so they are unlikely to resemble Earth.

The results of recent studies have shown that in our galaxy there are more terrestrial planets than previously thought, namely: from 11 to 40 billion. Scientists took as an example 42 thousand stars, similar to our Sun, and began to look for exoplanets that can orbit around them in a zone where it is not too hot and not too cold. Was found 603 exoplanets, among which 10 matched the search criteria.

By analyzing data about stars, scientists have proven the existence of billions of Earth-like planets that they have yet to officially discover. Theoretically, these planets are capable of maintaining temperatures for existence of liquid water on them, which, in turn, will allow life to arise.

Collision of galaxies

Even if new stars are constantly being formed in the Milky Way galaxy, it will not be able to increase in size, unless it gets new material from somewhere else. And the Milky Way is really expanding.

Previously, we were not sure exactly how the galaxy manages to grow, but recent discoveries have suggested that the Milky Way is galaxy-cannibal, meaning it has consumed other galaxies in the past and will likely do so again, at least until some larger galaxy swallows it.

Using a space telescope "Hubble" and information obtained from photographs taken over seven years, scientists have discovered stars at the outer edge of the Milky Way that move in a special way. Instead of moving toward or away from the center of the galaxy like other stars, they appear to drift toward the edge. It is believed that this star cluster is all that remains of another galaxy that was absorbed by the Milky Way galaxy.

This collision apparently occurred several billion years ago and, most likely, it will not be the last. Considering the speed at which we are moving, our galaxy through 4.5 billion years will collide with the Andromeda galaxy.

Influence of satellite galaxies

Although the Milky Way is a spiral galaxy, it is not exactly a perfect spiral. At its center there is a kind of bulge, which appeared as a result of hydrogen gas molecules escaping from the flat disk of the spiral.

For years, astronomers have puzzled over why the galaxy has such a bulge. It is logical to assume that the gas is drawn into the disk itself, and does not escape out. The longer they studied this question, the more confused they became: the molecules of the bulge are not only pushed outward, but also vibrate at their own frequency.

What could cause this effect? Today, scientists believe that dark matter and satellite galaxies are to blame - Magellanic Clouds. These two galaxies are very small: taken together they make up only 2 percent of the total mass of the Milky Way. This is not enough to have an impact on him.

However, when dark matter moves through the clouds, it creates waves that apparently influence the gravitational attraction, strengthening it, and hydrogen under the influence of this attraction escapes from the center of the galaxy.

Magellanic Clouds orbit the Milky Way. The spiral arms of the Milky Way, under the influence of these galaxies, seem to sway in the place where they pass.

Twin galaxies

Although the Milky Way galaxy can be called unique in many respects, it is not very rare. Spiral galaxies predominate in the Universe. Considering that only in our field of vision are about 170 billion galaxies, we can assume that somewhere there are galaxies very similar to ours.

What if there is a galaxy somewhere - an exact copy of the Milky Way? In 2012, astronomers discovered such a galaxy. It even has two small moons that orbit it that exactly match our Magellanic Clouds. By the way, only 3 percent spiral galaxies have similar companions, whose lifespan is relatively short. The Magellanic Clouds are likely to dissolve in a couple of billion years.

To discover such a similar galaxy, with satellites, a supermassive black hole in the center and the same size, is incredible luck. This galaxy was named NGC 1073 and it's so similar to the Milky Way that astronomers are studying it to find out more about our own galaxy. For example, we can see it from the side and thus better imagine what the Milky Way looks like.

Galactic year

On Earth, a year is the time during which the Earth manages to make full revolution around the Sun. Every 365 days we return to the same point. Our solar system revolves in the same way around a black hole located at the center of the galaxy. However, it makes a full revolution in 250 million years. That is, since the dinosaurs disappeared, we have only made a quarter of a full revolution.

Descriptions of the solar system rarely mention that it moves through space, like everything else in our world. Relative to the center of the Milky Way, the solar system moves at a speed 792 thousand kilometers per hour. To put it into perspective, if you were moving at the same speed, you could travel around the world in 3 minutes.

The period of time during which the Sun manages to make a complete revolution around the center of the Milky Way is called galactic year. It is estimated that the Sun has lived only 18 galactic years.

The Milky Way Galaxy contains the solar system, Earth and all the stars that are visible to the naked eye. Together with the Triangulum Galaxy, Andromeda Galaxy and dwarf galaxies and satellites, it forms the Local Group of galaxies, which is part of the Virgo Supercluster.

According to ancient legend, when Zeus decided to make his son Hercules immortal, he placed him on the breast of his wife Hera to drink milk. But the wife woke up and, seeing that she was feeding her stepchild, pushed him away. A stream of milk splashed out and turned into the Milky Way. In the Soviet astronomical school it was simply called the “Milky Way system” or “our Galaxy.” Outside Western culture, there are many names for this galaxy. The word “milky” is replaced by other epithets. The galaxy consists of about 200 billion stars. Most of them are located in the shape of a disk. Most of the Milky Way's mass is contained in a halo of dark matter.

In the 1980s, scientists proposed that the Milky Way is a barred spiral galaxy. The hypothesis was confirmed in 2005 using the Spitzer telescope. It turned out that the central bar of the galaxy is larger than previously thought. The diameter of the galactic disk is approximately 100 thousand light years. Compared to the halo, it rotates much faster. At different distances from the center its speed is not the same. Studies of the disk's rotation have helped estimate its mass, which is 150 billion more than the mass of the Sun. Near the plane of the disk, young star clusters and stars are collected, which form a flat component. Scientists suspect that many galaxies have black holes at their cores.

A large number of stars are collected in the central regions of the Milky Way Galaxy. The distance between them is much smaller than in the vicinity of the Sun. The length of the galactic bridge, according to scientists, is 27 thousand light years. It passes through the center of the Milky Way at an angle of 44 degrees ± 10 degrees to the line between the center of the galaxy and the Sun. Its components are predominantly red stars. The jumper is surrounded by a ring called the 5 kiloparsec ring. It contains a large amount of molecular hydrogen. It is also an active star-forming region in the Galaxy. If observed from the Andromeda Galaxy, the Milky Way bar would be its brightest part.

Since the Milky Way Galaxy is considered to be spiral, it has spiral arms that are located in the plane of the disk. Around the disk is a spherical corona. The solar system is located 8.5 thousand parsecs from the center of the galaxy. According to recent observations, we can say that our Galaxy has 2 arms and a couple more arms in the inner part. They transform into a four-armed structure, which is observed in the neutral hydrogen line.

The galaxy's halo has a spherical shape that extends beyond the Milky Way by 5–10 thousand light years. Its temperature is approximately 5 * 10 5 K. The halo consists of old, low-mass, dim stars. They can be found both in the form of globular clusters and individually. The bulk of the galaxy's mass is dark matter, forming a dark matter halo. Its mass is approximately 600–3000 billion solar masses. Star clusters and halo stars move around the galactic center in elongated orbits. The halo rotates very slowly.

History of the discovery of the Milky Way Galaxy

Many celestial bodies are combined into various rotating systems. Thus, the Moon revolves around the Earth, and the satellites of the major planets form their own systems. The Earth and other planets revolve around the Sun. Scientists had a completely logical question: is the Sun part of an even larger system?

William Herschel first tried to answer this question. He calculated the number of stars in different parts of the sky and found out that there is a large circle in the sky - the galactic equator, dividing the sky into two parts. Here the number of stars turned out to be greatest. The closer this or that part of the sky is located to this circle, the more stars there are on it. Ultimately, it was discovered that the Milky Way is located at the equator of the galaxy. Herschel came to the conclusion that all the stars form one star system.

Initially, it was believed that everything in the Universe is part of our galaxy. But Kant also argued that some nebulae could be separate galaxies, like the Milky Way. It was only when Edwin Hubble measured the distance to some spiral nebulae and showed that they could not be part of the Galaxy that Kant's hypothesis was proven.

Future of the Galaxy

In the future, collisions of our Galaxy with others, including Andromeda, are possible. But there are no specific predictions yet. It is believed that in 4 billion years the Milky Way will engulf the Small and Large Magellanic Clouds, and in 5 billion years it will be engulfed by the Andromeda Nebula.

Planets of the Milky Way

Despite the fact that stars are constantly born and die, their number is clearly calculated. Scientists believe that at least one planet revolves around every star. This means that there are from 100 to 200 billion planets in the Universe. The scientists who worked on this claim studied red dwarf stars. They are smaller than the Sun and make up 75% of all the stars in the Milky Way Galaxy. Particular attention was paid to the star Kepler-32, which “hosted” 5 planets.

Planets are much more difficult to detect than stars because they do not emit light. We can confidently say about the existence of a planet only when it obscures the light of a star.

There are also planets that are similar to our Earth, but there are not so many of them. There are many types of planets, such as pulsar planets, gas giants, brown dwarfs... If the planet is made of rocks, it will not look much like Earth.

Recent studies claim that there are from 11 to 40 billion Earth-like planets in the galaxy. Scientists examined 42 stars similar to the Sun and discovered 603 exoplanets, 10 of which met the search criteria. It has been proven that all planets similar to Earth can maintain the necessary temperature for the existence of liquid water, which, in turn, will help the emergence of life.

Near the outer edge of the Milky Way, stars have been discovered that move in a special way. They drift at the edge. Scientists suggest that this is all that remains of the galaxies that were swallowed up by the Milky Way. Their encounter happened many years ago.

Galaxy satellites

As we have already said, the Milky Way Galaxy is spiral. It is a spiral of imperfect shape. For many years, scientists could not find an explanation for the galaxy's bulge. Now everyone has come to the conclusion that this is due to satellite galaxies and dark matter. They are very small and cannot influence the Milky Way. But when dark matter moves through the Magellanic Clouds, waves are created. They influence gravitational attractions. Under this action, hydrogen evaporates from the galactic center. Clouds orbit the Milky Way.

Although the Milky Way is called unique in many respects, it is not very rare. If we take into account the fact that there are approximately 170 billion galaxies in the field of view, we can argue about the existence of galaxies similar to ours. In 2012, astronomers found an exact copy of the Milky Way. It even has two moons that correspond to the Magellanic Clouds. By the way, it is assumed that in a couple of billion years they will dissolve. Finding such a galaxy was an incredible success. It was named NGC 1073. It is so similar to the Milky Way that astronomers are studying it to learn more about our galaxy.

Galactic year

An Earth year is the time it takes for the planet to make a full revolution around the Sun. In the same way, the solar system revolves around a black hole, which is located at the center of the galaxy. Its full revolution is 250 million years. When the Solar System is described, it is rarely mentioned that it moves through space, like everything else in the world. Its speed is 792,000 km per hour relative to the center of the Milky Way Galaxy. If we compare, we, moving at a similar speed, could go around the whole world in 3 minutes. A galactic year is the time it takes for the Sun to complete one revolution around the Milky Way. At last count, the sun lived for 18 galactic years.