The number of stars in our galaxy is approx. How many stars are there in the milky way

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Milky Way– spiral galaxy with solar system: interesting facts, size, area, detection and name, study with video, structure, location.

The Milky Way is a spiral galaxy spanning an area of ​​100,000 light years in which the solar system is located.

If you have a place further away from the city, where it is dark and has a beautiful view of the starry sky, you may notice a faint streak of light. This is a group with millions of small bright lights and glowing halos. The stars are before you Milky Way galaxy.

But what is she? To begin with, the Milky Way is a barred spiral galaxy that is home to the Solar System. It is difficult to call the home galaxy something unique, because there are hundreds of billions of other galaxies in the Universe, many of which are similar.

Interesting facts about the Milky Way galaxy

• The Milky Way began forming as a cluster of dense regions after the Big Bang. The first stars to appear were in globular clusters, which continue to exist. These are the oldest stars in the galaxy;
• The galaxy increased its parameters due to absorption and merger with others. It is now taking stars from the Sagittarius Dwarf Galaxy and the Magellanic Clouds;
• The Milky Way moves through space with an acceleration of 550 km/s relative to the cosmic microwave background radiation;
• The supermassive black hole Sagittarius A* lurks at the galactic center. Its mass is 4.3 million times greater than that of the Sun;
• Gas, dust and stars rotate around the center at a speed of 220 km/s. This is a stable indicator, implying the presence of a dark matter shell;
• In 5 billion years, a collision with the Andromeda Galaxy is expected. Some believe that the Milky Way is a giant spiral double system;

Discovering and naming the Milky Way galaxy

Our Milky Way galaxy has a rather interesting name, as the hazy haze resembles a trail of milk. The name has ancient roots and is translated from the Latin “Via Lactea”. This name appears already in the work “Tadhira” by Nasir ad-Din Tusi. He wrote: “Represented by many small and densely grouped stars. They are located close together, so they appear like spots. The color resembles milk...” Admire a photo of the Milky Way galaxy with its arms and center (of course, no one can take a photo of our galaxy, but there are similar designs and precise structural data that provide an idea of ​​​​the appearance of the galactic center and arms).

Scientists thought the Milky Way was filled with stars, but this remained a guess until 1610. It was then that Galileo Galilei pointed the first telescope into the sky and saw individual stars. It also revealed a new truth to people: there are many more stars than we thought, and they are part of the Milky Way.

Immanuel Kant in 1755 believed that the Milky Way is a collection of stars united by a shared gravity. The gravitational force causes objects to spin and flatten into a disk shape. In 1785, William Herschel tried to recreate the galactic shape, but did not realize that most of it was hidden behind a haze of dust and gas.

The situation changes in the 1920s. Edwin Hubble managed to convince us that we do not see spiral nebulae, but individual galaxies. It was then that the opportunity arose to realize our form. From that moment it became clear that this was a barred spiral galaxy. Watch the video to explore the structure of the Milky Way galaxy and explore its globular clusters and find out how many stars live in the galaxy.

Our galaxy: a view from the inside

Astrophysicist Anatoly Zasov about the main components of our galaxy, the interstellar medium and globular clusters:

Location of the Milky Way Galaxy

The Milky Way in the sky is quickly recognized thanks to its wide and elongated white line, reminiscent of a milky trail. Interestingly, this star group has been visible since the formation of the planet. In fact, this area acts as the galactic center.

The galaxy extends 100,000 light years in diameter. If you were able to look at it from above, you would notice a bulge in the center, from which 4 large spiral arms emanate. This type represents 2/3 of the universe's galaxies.

Unlike the usual spiral, specimens with a jumper contain a rod in the center with two branches. Our galaxy has two main arms and two minor ones. Our system is located in the Orion Arm.

The Milky Way is not static and rotates in space, carrying all objects with it. The solar system moves around the galactic center at a speed of 828,000 km/h. But the galaxy is incredibly huge, so one passage takes 230 million years.

Spiral arms accumulate a lot of dust and gas, creating excellent conditions for the formation of new stars. The arms extend from the galactic disk, spanning approximately 1,000 light years.

At the center of the Milky Way you can see a bulge filled with dust, stars and gas. This is why you only get to see a small percentage of the total number of stars in the galaxy. It's all about the thick gas and dust haze that blocks the view.

In the very center lies a supermassive black hole, billions of times more massive than the Sun. Most likely, it used to be much smaller, but a regular diet of dust and gas allowed it to grow. This is an incredible glutton, because sometimes even stars are sucked in. Of course, it is impossible to see it directly, but the gravitational influence is monitored.

Around the galaxy is a halo of hot gas, where old stars and globular clusters live. It extends over hundreds of thousands of light years, but contains only 2% of the stars that are in the disk. Let's not forget about dark matter (90% of the galactic mass).

Structure and composition of the Milky Way galaxy

When observed, it is clear that the Milky Way divides the celestial space into two almost identical hemispheres. This suggests that our system is located near the galactic plane. It is noticeable that the galaxy has a low level of surface brightness due to the fact that gas and dust are concentrated in the disk. This not only makes it impossible to see the galactic center, but also to understand what is hiding on the other side. You can easily spot the center of the Milky Way galaxy in the diagram below.

If you were able to escape beyond the Milky Way and get a top-down perspective, you would see a spiral with a bar. It extends over 120,000 light years and is 1000 light years wide. For many years, scientists thought they saw 4 arms, but there are only two of them: Scutum-Centauri and Sagittarius.

The arms are created by dense waves rotating around the galaxy. They move around the area, so they compress dust and gas. This process triggers the active birth of stars. This happens in all galaxies of this type.

If you have come across photos of the Milky Way, then they are all artistic interpretations or other similar galaxies. It was difficult for us to comprehend its appearance, since we are located inside. Imagine that you want to describe the outside of a house if you have never left its walls. But you can always look out the window and look at the neighboring buildings. In the bottom picture you can easily understand where the Solar System is located in the Milky Way galaxy.

Ground and space missions have revealed that the galaxy is home to 100-400 billion stars. Each of them can have one planet, that is, the Milky Way galaxy is capable of housing hundreds of billions of planets, 17 billion of which are similar in size and mass to Earth.

Approximately 90% of the galactic mass goes to dark matter. No one can explain what we are facing. In principle, it has not yet been seen, but we know about its presence thanks to the rapid galactic rotation and other influences. It is this that keeps galaxies from being destroyed during rotation. Watch the video to learn more about the stars of the Milky Way.

Stellar population of the galaxy

Astronomer Alexey Rastorguev on the age of stars, star clusters and properties of the galactic disk:

Position of the Sun in the Milky Way Galaxy

Between the two main arms is the Orion Arm, in which our system is located 27,000 light-years from the center. There is no point in complaining about the remoteness, because a supermassive black hole (Sagittarius A*) lurks in the central part.

It takes our star, the Sun, 240 million years to orbit the galaxy (a cosmic year). This sounds incredible, because the last time the Sun was in this area, dinosaurs roamed the Earth. During its entire existence, the star made approximately 18-20 flybys. That is, it was born 18.4 space years ago, and the age of the galaxy is 61 space years.

Collision trajectory of the Milky Way galaxy

The Milky Way not only rotates, but also moves in the Universe itself. And although the space is large, no one is immune from collisions.

It is estimated that in about 4 billion years, our Milky Way galaxy will collide with the Andromeda galaxy. They are approaching at a speed of 112 km/s. After the collision, the process of star birth is activated. Overall, Andromeda is not the neatest racer, as it has crashed into other galaxies in the past (noticeably large dust ring in the center).

But earthlings should not worry about the future event. After all, by that time the Sun will already explode and destroy our planet.

What's next for the Milky Way galaxy?

It is believed that the Milky Way was created by the merger of smaller galaxies. This process continues, as the Andromeda galaxy is already rushing towards us to create a giant ellipse in 3-4 billion years.

The Milky Way and Andromeda do not exist in isolation, but are part of the Local Group, which is also part of the Virgo Supercluster. This gigantic region (110 million light years) is home to 100 groups and galaxy clusters.

If you haven’t been able to admire your native galaxy, then do it as soon as possible. Find a quiet and dark place with an open sky and just enjoy this amazing star collection. Let us remind you that the site has a virtual 3D model of the Milky Way galaxy, which allows you to study all the stars, clusters, nebulae and known planets online. And our star map will help you find all these celestial bodies in the sky yourself if you decide to buy a telescope.

Position and movement of 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.

In which the solar system and planet Earth are located. It has the shape of a barred spiral, several arms extend from the center, and all the stars in the Galaxy revolve around its core. Our Sun is located almost on the very outskirts and makes a full revolution every 200 million years. It forms the planetary system most known to mankind, called the Solar system. It consists of eight planets and many other space objects that formed from a cloud of gas and dust about four and a half billion years ago. The solar system is relatively well studied, but stars and other objects beyond it are located at enormous distances, despite belonging to the same Galaxy.

All the stars that humans can observe with the naked eye from Earth are in the Milky Way. The galaxy under this name should not be confused with a phenomenon that appears in the night sky: a bright white stripe crossing the sky. This is part of our Galaxy, a large cluster of stars that looks this way because the Earth is located next to its plane of symmetry.

Planetary systems in the Galaxy

Only one planetary system is called Solar - the one in which the Earth is located. But there are many more systems in our Galaxy, only a small part of which has been discovered. Until 1980, the existence of systems similar to ours was only hypothetical: observation methods did not allow us to detect such relatively small and dim objects. The first assumption about their existence was made by astronomer Jacob from the Madras Observatory in 1855. Finally, in 1988, the first planet outside the solar system was found - it belonged to the orange giant Gamma Cephei A. Then other discoveries followed, and it became clear that there could be many of them. Such planets that do not belong to our system are called exoplanets.

Today, astronomers know more than a thousand planetary systems, about half of which have more than one exoplanet. But there are still many candidates for this title who cannot yet confirm this data. Scientists suggest that there are about one hundred billion exoplanets in our Galaxy, which belong to several tens of billions of systems. Perhaps about 35% of all sun-like stars in the Milky Way are not alone.

Some planetary systems found are completely different from the Solar system, others are more similar. In some there are only gas giants (for now there is more information about them, since they are easier to detect), in others there are planets similar to the Earth.

Related article

A galaxy is a system of stars, dust, gas and dark matter held together by gravitational forces. Behind such a prosaic description lies the beauty of millions of shining stars. Some galaxies are named after the constellations in which they are located, and some have beautiful, unique names.

Instructions

Galaxies are named after the greats, discoverers and other outstanding figures and artists (for example, the Magellanics). You might name a galaxy after your mentor who gave you an important start and you would like to express your gratitude to him in this way. Or you can name the galaxy after the traveler whose adventures you read as a child and whom you still admire.

If you have a loved one, name the galaxy after him. Now, when asked “give me a star,” you can always answer: “I’m giving you a whole galaxy!”, and your lover will be very pleased. In addition, some entomological scientists name discovered species of insects after their wives, and they are happy that their husbands decide to perpetuate their names in this way.

Give the name of the ancient Greek goddess. The pantheon of goddesses was quite large, and every reader of ancient Greek myths has a favorite character from these legends. The splendor and scale of the galaxy will be well suited to the name of a proud, beautiful and powerful goddess.

You can always name the galaxy after its discoverer, that is, yours. At the same time, you will become widely known throughout the world. Also, you will have thousands of schoolchildren when in astronomy lessons they are asked “who is the Ivanova galaxy?”

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Helpful advice

Call it what you hold dear. Let the whole world be outraged by the absurdity of your choice. If you are eligible to register the name of a new galaxy, they will have to accept it. So you can call your galaxy either Hair of Veronica or spaghetti with cheese.

There are more than 100 billion stars in our Galaxy; according to the spectral classification, they are classified into one type or another. Stars are divided into spectral classes - O, B, A, F, G, K, M, each of them is characterized by a certain temperature, as well as true and visible colors.

Instructions

There are stars that do not fall into any of the spectral classes; they are called peculiar. They are often normal stars at a certain evolutionary stage. Stars with peculiar spectra have different features of their chemical composition that enhance or weaken the spectral lines of a number of elements. Such stars may not be typical for the immediate vicinity of the Sun, for example, metal-poor stars of globular clusters or galactic haloes.

Most stars belong to the main sequence, they are called normal, such stars include the Sun. Depending on what stage of evolutionary development a star is at, it is classified as a normal star, dwarf or giant star.

A star can be a red giant at the time of formation, as well as in the later stages of its development. At the earliest stage of development, the star radiates due to the gravitational energy that is released during its development. This continues until a thermonuclear reaction begins. After burning out hydrogen, stars converge toward the main sequence, moving into the region of red giants and supergiants.

Giant stars are characterized by a relatively low temperature - about 5000 K. They have a very large radius and enormous luminosity, the maximum radiation falls in the red and infrared part of the spectrum, for this reason they are often giants.

Dwarf stars are divided into several subtypes: white, red, black, brown and subbrown dwarfs. Former dwarfs are stars that have passed through stages of their evolution. Their mass does not exceed 1.4 times that of the sun; they are deprived of their own sources of thermonuclear energy. The diameter of white dwarfs can be hundreds of times smaller than that of the sun, and their density can be a million times greater than that of water.

Red dwarfs are significantly different from other stars. These are small and relatively cool main sequence stars with a spectral M or K. Their diameter does not exceed a third of the solar one; the lower mass limit for this type of star is 0.08 of the solar one.

Black dwarfs are cooled white dwarfs that do not emit visible light. They represent the final stage of the evolution of white dwarfs. Their mass is limited above 1.4 solar masses.

Brown dwarfs are substellar objects whose masses are in the range of 5-75 Jupiter masses, and whose diameter is approximately equal to the diameter of this planet. Unlike main sequence stars, thermonuclear fusion reactions do not occur in their interiors. Subbrown dwarfs are cool formations and have less mass than brown dwarfs. Some astronomers consider them planets.

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Sources:

• astrotime.ru, Types of stars

Until recently, the largest star in the Milky Way galaxy was known: Herschel's Garnet Star from the constellation Cassiopeia rightfully held this title. But three more were recently discovered.

Scientists accept the fact that the red supergiant VV located in the constellation Cepheus may be larger than these stars, but under the influence of the gravity of the accompanying planet it is greatly deformed, which makes it difficult to accurately answer the question.

In July 2013, scientists were able to observe from beginning to end the process of the birth of a star that is 500 times the mass of the Sun and emits light several million times brighter. With the help of powerful telescopes, scientists can see the moment of birth in every detail. During the birthing process, a huge cloud of dust and gases was pulled inward under the influence of gravity, forming a new star. When observing this part of the galaxy, no one could have predicted such a result: they expected the appearance of a star that would be a hundred times larger than the Sun. This happened in the constellation Triangle, 10 thousand light years away from Earth. Such titans are rare, and it is almost impossible to catch the moment of their birth. Formation in these stars occurs very quickly due to their size, and the young star remains very short.

The largest and brightest known star can also be called VY Canis Majoris, which is unique in many respects. Stars of this size most often belong to several star systems, but this is a single star. The diameter of this hypergiant is approximately 3 billion km. For example, if you place VY Canis Majoris at the center of the solar system instead of the Sun, it will occupy space up to the orbit of Saturn. The star's radiation occurs in infrared light, and scientists have not yet come to a consensus about its properties. There are theories that it is a big red one, and also that it is a supergiant, only very large. VY Canis Majoris is located approximately 4,500 light years from Earth, and its condition suggests that it, like any supernova, can explode at any moment. Its dying core has almost completely burned out its supply of hydrogen and helium and consists mainly of carbon, oxygen and nitrogen. The star has already begun the active emission of substances preceding the explosion.

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Sources:

• The largest star in the Universe

quoted1 > > Where is the Earth located in the Milky Way?

Place of the Earth and the Solar System in the Milky Way Galaxy: where the Sun and planet are located, parameters, distance from the center and plane, structure with photo.

For many centuries, scientists believed that the Earth was the center of the entire Universe. It’s not hard to think why this happened, because the Earth is in and we couldn’t look beyond it. Only a century of research and observation helped to understand that all celestial bodies in the system revolve around the main star.

The system itself also rotates around the galactic center. Although then people did not understand this either. We had to spend a certain period of time to guess about the existence of many galaxies and determine their place in ours. What place does Earth occupy in the Milky Way galaxy?

Location of the Earth in the Milky Way

Earth is located in the Milky Way galaxy. We live in a huge and spacious place, spanning 100,000-120,000 light years in diameter and approximately 1000 light years in width. The territory is home to 400 billion stars.

The galaxy received such a scale thanks to its unusual diet - it absorbed and continues to be fed by other small galaxies. For example, on the dinner table right now is the Canis Major Dwarf Galaxy, whose stars join our disk. But if we compare with others, ours is average. Even the next one is twice as large.

Structure

The planet lives in a spiral-type galaxy with a bar. For many years it was thought that there were 4 arms, but recent studies confirm only two: Scutum-Centauri and Carina-Sagittarius. They emerged from dense waves orbiting the galaxy. That is, these are grouped stars and gas clouds.

What about a photo of the Milky Way galaxy? All of them are artistic interpretations or real photographs, but very similar to our galaxies. Of course, we didn’t come to this right away, since no one could say exactly what it looks like (after all, we are inside it).

Modern instruments allow us to count up to 400 billion stars, each of which can have a planet. 10-15% of the mass goes to “luminous matter”, and the rest is stars. Despite the huge array, only 6000 light years in the visible spectrum are open to us for observation. But here infrared devices come into play, opening up new territories.

Around the galaxy there is a huge halo of dark matter, covering as much as 90% of the total mass. No one yet knows what it is, but its presence confirms the impact on other objects. It is believed that it keeps the Milky Way from disintegrating as it rotates.

Location of the Solar System in the Milky Way

The Earth is 25,000 light years away from the galactic center and the same amount from the edge. If you imagine the galaxy as a giant musical record, then we are located halfway between the central part and the edge. More specifically, we occupy a place in the Orion arm between the two main arms. It extends 3,500 light-years in diameter and stretches out to 10,000 light-years.

The galaxy can be seen dividing the heavens into two hemispheres. This suggests that we are located close to the galactic plane. The Milky Way has a low surface brightness due to the abundance of dust and gas obscuring the disk. This makes it difficult not only to see the central part, but also to look at the other side.

The system takes 250 million years to complete its entire orbital path—a “cosmic year.” During their last passage, dinosaurs roamed the Earth. And what will happen next? Will people go extinct or will they be replaced by a new species?

In general, we live in a huge and amazing place. New knowledge makes one get used to the fact that the Universe is much larger than all assumptions. Now you know where Earth is in the Milky Way.

In our age, illuminated by hundreds of electric lights, city residents have no opportunity to see the Milky Way. This phenomenon, which appears in our sky only during a certain period of the year, is observed only far from large populated areas. In our latitudes it is especially beautiful in August. In the last month of summer, the Milky Way rises above the Earth in the form of a giant celestial arch. This weak, blurry strip of light appears 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 heaven, the Road of the Gods and the magical Heavenly River carrying divine milk. At the same time, all peoples believed that the Milky Way was something sacred. The radiance was worshiped. Even temples were built in his honor.

Few people know that our New Year tree is an echo of the cults of people who lived in former times. Indeed, in ancient times it was believed that the Milky Way was the axis of the Universe or the World Tree, on whose branches stars ripened. That is why at the beginning of the annual cycle they decorated the Christmas 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 a good harvest. So great was the importance of the Milky Way for our ancestors.

Scientific assumptions

What is the Milky Way? The history of the discovery of this phenomenon goes back almost 2000 years. Plato also called this strip of light a seam connecting the celestial hemispheres. In contrast to this, Anaxagoras and Demoxide argued that the Milky Way (we’ll look at what color it is) is a kind of illumination of stars. She is the decoration of the night sky. Aristotle explained that the Milky Way is the glow of luminous lunar vapors in the air of our planet.

There were many other assumptions. Thus, the Roman Marcus 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 was part of the solar system.

Galileo's discovery

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 was a real cluster of stars, which, when viewed with the naked eye, merged into a continuous, faintly flickering strip. Galileo even managed to explain the heterogeneity of the structure of this band.

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

William Herschel's discovery

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

It was only in the 1920s that the work of Jacobus Kaptein was published, in which the Milky Way was described in the most detail. At the same time, the author gave a diagram of the star island, as similar as possible to the one that is currently known to us. Today we know that the Milky Way is a Galaxy that contains the Solar System, the Earth and those individual stars that are visible to humans with the naked eye.

Structure of galaxies

With the development of science, astronomical telescopes became more and more powerful. At the same time, the structure of the observed galaxies became increasingly clear. It turned out that they are not similar to each other. Some of them were incorrect. Their structure had no symmetry.

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

general characteristics

The Milky Way is a spiral galaxy. Moreover, it has a bridge in the form of a huge interconnected gravitational force.

The Milky Way is believed to have existed for over thirteen billion years. This is the period during which about 400 billion constellations and stars, over a thousand huge gas nebulae, clusters and clouds were 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 whose diameter is 100 thousand light years (one such light year is ten trillion kilometers). The thickness is 15 thousand, and the depth is about 8 thousand light years.

How much does the Milky Way weigh? It is not possible to calculate this (determining its mass is a very difficult task). Difficulties arise in determining the mass of dark matter, which does not interact with electromagnetic radiation. This is why astronomers cannot definitively answer this question. But there are rough calculations according to which the weight of the Galaxy ranges from 500 to 3000 billion solar masses.

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

What parts does the Milky Way consist of? These are the core and bridges, the disc and spiral arms, and the crown. Let's take a closer look at them.

Core

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. At the center of this part of the Milky Way is a compaction called a “bulge.” This is a whole string of old stars that moves along an elongated orbit. Most of these celestial bodies are already reaching the end of their life cycle.

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 the most powerful gravity. Another black hole rotates around it, only smaller. Such a system creates such a force that nearby constellations and stars move along very unusual trajectories.

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

It is also interesting that, observing the nuclei of other galaxies, astronomers note their bright shine. But why is it not visible in the Milky Way? Some researchers have even suggested that there is no core in our Galaxy. However, it was determined that in spiral nebulae there are dark layers that are interstellar accumulations of dust and gas. They are also found in the Milky Way. These huge dark clouds prevent the earthly observer from seeing the glow 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 one hundred moons.

Modern telescopes, which are capable of operating in special ranges of the electromagnetic spectrum of radiation, have helped people answer this question. With the help of this modern technology, which 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 bridge consists of 22 million red stars of impressive age. Around this formation there is a gas ring, which contains a large percentage of molecular oxygen. All this suggests that the Milky Way bar is the area where stars are formed in the greatest number.

Disk

The Milky Way itself has this shape, which is in constant rotational motion. Interestingly, the speed of this process depends on the distance of a particular area 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.

The outer side of the Milky Way is surrounded by 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 gas clusters with a temperature of 10 thousand degrees. The thickness of such formations is several thousand light years.

Five spiral arms

These are another component of the Milky Way, located directly behind the gas ring. The spiral arms cross the constellations Cygnus and Perseus, Orion and Sagittarius, and Centaurus. These formations are unevenly filled with molecular gas. This composition introduces errors into the rules of rotation of the Galaxy.
The spiral arms extend directly from the core of the star island. We observe them with the naked eye, calling the light strip the Milky Way.

The 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 extends beyond the boundaries of the Galaxy by 50 light years.

The Milky Way's corona typically contains low-mass and old stars, as well as dwarf galaxies and hot gas clusters. All these components move in elongated orbits around the nucleus, performing random rotation.

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

Location of stars

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

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

Our planet is located in the so-called corotation circle. This is a place where the rotation speeds 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 are a small number of stars.

Our Earth was such a planet. It is located on the periphery of the Galaxy, in its quietest place. This is why there have been no global cataclysms on our planet for several billion years, which 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 about the magnitude 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 it, four billion years will pass, and the Milky Way will absorb the Magellanic Clouds (Large and Small), and in another billion years it itself will become part of the Andromeda Nebula.