Astronomers say that with the naked eye a person can see about 4.5 thousand stars. And this, despite the fact that only a small part of one of the most amazing and unidentified pictures of the world is revealed to our eyes: in the Milky Way Galaxy alone there are more than two hundred billion heavenly bodies(scientists have the opportunity to observe only two billion).
Milky Way is a barred spiral galaxy, representing a huge star system gravitationally bound in space. Together with the neighboring Andromeda and Triangulum galaxies and more than forty dwarf satellite galaxies, it is part of the Virgo Supercluster.
The age of the Milky Way exceeds 13 billion years, and during this time from 200 to 400 billion stars and constellations, more than a thousand huge gas clouds, clusters and nebulae have formed in it. If you look at a map of the Universe, you can see that the Milky Way is presented on it in the form of a disk with a diameter of 30 thousand parsecs (1 parsec is equal to 3.086 * 10 to the 13th power of kilometers) and an average thickness of about a thousand light years (one light year almost 10 trillion kilometers).
Astronomers find it difficult to answer exactly how much the Galaxy weighs, since most of weight is not contained in the constellations, as previously thought, but in dark matter, which does not emit or interact with electromagnetic radiation. According to very rough calculations, the weight of the Galaxy ranges from 5*10 11 to 3*10 12 solar masses.
Like all celestial bodies, the Milky Way rotates around its axis and moves around the Universe. It should be taken into account that when moving, galaxies constantly collide with each other in space and the one that has more large sizes, absorbs smaller ones, but if their sizes coincide, active star formation begins after the collision.
Thus, astronomers suggest that in 4 billion years the Milky Way in the Universe will collide with the Andromeda Galaxy (they are approaching each other at a speed of 112 km/s), causing the emergence of new constellations in the Universe.
As for the movement around its axis, the Milky Way moves unevenly and even chaotically in space, since each star system, cloud or nebula located in it has its own speed and orbits different types and forms.
Galaxy structure
If you look closely at a map of space, you can see that the Milky Way is very compressed in the plane and looks like a “flying saucer” ( solar system located almost at the very edge of the star system). The Milky Way Galaxy consists of a core, a bar, a disk, spiral arms and a crown.
Core
The core is located in the constellation Sagittarius, where there is a source of non-thermal radiation, the temperature of which is about ten million degrees - a phenomenon characteristic only of the nuclei of galaxies. In the center of the core there is a compaction - a bulge, consisting of large number old stars moving in an elongated orbit, many of which are at the end of their life cycle.
So, some time ago, American astronomers discovered an area here measuring 12 by 12 parsecs, consisting of dead and dying constellations.
At the very center of the core is a supermassive black hole(an area in outer space that has such powerful gravity that even light is unable to leave it), around which a smaller black hole rotates. Together they are so powerful gravitational influence to the stars and constellations located not far from them, that they move in unusual ways for celestial bodies trajectories in the Universe.
Also, the center of the Milky Way is characterized by an extremely strong concentration of stars, the distance between which is several hundred times less than at the periphery. The speed of movement of most of them is absolutely independent of how far they are from the core, and therefore average speed rotation ranges from 210 to 250 km/s.
Jumper
A jumper measuring 27 thousand light years crosses central part Galaxies at an angle of 44 degrees to conditional line between the Sun and the core of the Milky Way. It consists mainly of old red stars (about 22 million), and is surrounded by a gas ring that contains most of the molecular hydrogen, and therefore is the region where stars are formed in the greatest number. According to one theory, such active star formation occurs in the bridge due to the fact that it passes gas through itself, from which constellations are born.
Disk
The Milky Way is a disk consisting of constellations, gas nebulae and dust (its diameter is about 100 thousand light years with a thickness of several thousand). The disk rotates much faster than the corona, which is located at the edges of the Galaxy, while the rotation speed at different distances from the core is unequal and chaotic (varies from zero in the core to 250 km/h at a distance of 2 thousand light years from it). Gas clouds, as well as young stars and constellations, are concentrated near the plane of the disk.
WITH outside The Milky Way contains a layer of atomic hydrogen, which extends into space one and a half thousand light years from the outer spirals. Despite the fact that this hydrogen is ten times thicker than in the center of the Galaxy, its density is just as many times lower. On the outskirts of the Milky Way, dense accumulations of gas with a temperature of 10 thousand degrees, the dimensions of which exceed several thousand light years, were discovered.
Spiral sleeves
Immediately behind the gas ring there are five main spiral arms of the Galaxy, the size of which ranges from 3 to 4.5 thousand parsecs: Cygnus, Perseus, Orion, Sagittarius and Centauri (the Sun is located from inside Orion's arms). Molecular gas is located unevenly in the arms and does not always obey the rules of rotation of the Galaxy, introducing errors.
Crown
The Milky Way's corona appears as a spherical halo that extends five to ten light years beyond the Galaxy. The corona consists of globular clusters, constellations, individual stars (mostly old and low-mass), dwarf galaxies, and hot gas. They all move around the core in elongated orbits, while the rotation of some stars is so random that even the speed of nearby stars can differ significantly, so the corona rotates extremely slowly.
According to one hypothesis, the corona arose as a result of the absorption of smaller galaxies by the Milky Way, and is therefore their remnants. According to preliminary data, the age of the halo exceeds twelve billion years and is the same age as the Milky Way, and therefore star formation here has already completed.
star space
If you look at the night starry sky, the Milky Way can be seen from absolutely any point globe in the form of a strip of lightish color (since our star system is located inside the Orion arm, only part of the Galaxy is accessible for viewing).
The map of the Milky Way shows that our Sun is located almost on the disk of the Galaxy, at its very edge, and its distance to the core is from 26-28 thousand light years. Considering that the Sun moves at a speed of about 240 km/h, to make one revolution, it needs to spend about 200 million years (over the entire period of its existence, our star has not flown around the Galaxy thirty times).
It is interesting that our planet is located in a corotation circle - a place where the speed of rotation of stars coincides with the speed of rotation of the arms, so stars never leave these arms or enter them. This circle is characterized by high level radiation, therefore it is believed that life can only arise on planets near which there are very few stars.
This fact also applies to our Earth. Being on the periphery, it is located in a fairly calm place in the Galaxy, and therefore for several billion years it was almost not subject to global cataclysms, for which the Universe is so rich. Perhaps this is one of the main reasons that life was able to originate and survive on our planet.
The content of the article
MILKY WAY, a hazy glow in the night sky from the billions of stars in our Galaxy. The Milky Way band encircles the sky in a wide ring. The Milky Way is especially visible away from city lights. In the Northern Hemisphere, it is convenient to observe it around midnight in July, at 10 pm in August or at 8 pm in September, when the Northern Cross of the Cygnus constellation is near the zenith. As we follow the Milky Way's shimmering streak north or northeast, we pass the W-shaped constellation Cassiopeia and head toward the bright star Capella. Behind the Capella, you can see how the less wide and bright part of the Milky Way passes slightly east of the Belt Orion and leans toward the horizon not far from Sirius, the brightest star in the sky. The brightest part of the Milky Way is visible to the south or southwest at times when the Northern Cross is overhead. At the same time, two branches of the Milky Way are visible, separated by a dark gap. The Scutum Cloud, which E. Barnard called “the jewel of the Milky Way,” is located halfway to the zenith, and below are the magnificent constellations Sagittarius and Scorpius.
Unfortunately, the brightest parts of the Milky Way are inaccessible to observers Northern Hemisphere. To see them, you need to go to the equator, or even better, position yourself between 20 and 40° S. and watch the sky approx. 10 pm in late April or early May. High in the sky is the Southern Cross, and low in the northwest is Sirius. The Milky Way runs between them, dim and narrow, but it becomes much brighter and more interesting 30° west of the Southern Cross, in the constellation Carina. As Sagittarius and Scorpio rise in the east, the brightest and most magnificent parts of the Milky Way appear. Its most remarkable area is visible late in the evening in June-July, when the Sagittarius Cloud is located near the zenith. Against the background of a uniform glow caused by thousands and thousands of distant stars invisible to the eye, one can notice dark clouds and “veins” of cold cosmic dust. Anyone who wants to understand the structure of our Galaxy should take the time to observe the Milky Way - this truly remarkable and most grandiose of celestial phenomena.
To discern the myriad stars that make up the Milky Way, all you need is binoculars or a small telescope. Highest concentration stars and the maximum width of the Milky Way are observed in the constellations Sagittarius and Scorpio; it is the least populated by stars opposite side sky - near Orion's Belt and Capella. Accurate astronomical observations confirm the first visual impression: a band of the Milky Way marks the central plane of a giant disk-shaped star system– our Galaxy, which is often called the “Milky Way Galaxy”. One of its stars is our Sun, located very close to the central plane of the Galaxy. However, the Sun is not at the center of the galactic disk, but at a distance of two-thirds from its center to the edge. The stars that make up the Milky Way are located at different distances from the Earth: some are no further than 100 light years. years, and most are removed by 10,000 sv. years and even further. The star cloud in Sagittarius and Scorpio marks the direction of the center of the Galaxy, located at a distance of approximately 30,000 light years from Earth. years. The diameter of the entire Galaxy is at least 100,000 light years. years.
Composition of the Milky Way.
The galaxy consists mainly of stars, more or less similar to the Sun. Some of them are several times more massive than the Sun and glow several thousand times brighter, others are several times less massive and glow several thousand times weaker. The Sun is, in many ways, an average star. Depending on the surface temperature, stars have different colour: blue-white stars are the hottest (20,000–40,000 K), and red stars are the coolest (approx. 2500 K).
Some stars form groups called star clusters. Some of them are visible to the naked eye, such as the Pleiades. This is a typical open cluster; Typically such clusters contain from 50 to 2000 stars. In addition to open clusters, there are much larger globular clusters containing up to several million stars. These clusters vary significantly in age and stellar composition. Open clusters are relatively young: their typical age is ca. 10 million years, i.e. OK. 1/500th the age of the Earth and the Sun. They contain many massive bright stars. Globular clusters very old: 10–15 billion years have passed since their formation, i.e. they consist of the oldest stars in the Galaxy, among which only low-mass ones have survived. Open clusters are located near the galactic plane, where there is a lot of interstellar gas from which stars form. Globular clusters fill the galactic halo surrounding the disk and are noticeably concentrated towards the center of the Galaxy.
The mass of the Galaxy is at least 2H 10 11 solar masses. These are mostly stars, but 5% of its mass is interstellar matter - gas and dust. Interstellar matter fills the space between stars in the galactic disk with a thickness of approx. 600 St. years, and inside the disk it concentrates towards the spiral arms of the Galaxy. A significant part of the interstellar matter is combined into massive cold clouds, in the depths of which stars form.
The Milky Way Galaxy is one of hundreds of millions of similar star systems discovered in the Universe using large telescopes. It is often called “our star system.” It refers to large galaxies, which has rapid rotation and clear spiral arms in which young hot stars and gas clouds heated by their radiation, called “emission nebulae,” are concentrated. Using optical telescopes, it is not possible to study the entire Galaxy, since light does not penetrate through dense interstellar clouds of gas and dust, which are especially numerous towards the center of the Galaxy. However for infrared radiation and radio emissions, dust is not a hindrance: with the help of appropriate telescopes, it is possible to explore the entire Galaxy and even break through to its dense core. Observations have shown that the stars and gas in the galactic disk are moving at a speed of about 250 km/s around the center of the Galaxy. Our Sun, together with the planets, also moves at the same speed, making one revolution around the galactic center in about 200 million years.
The Milky Way is our home galaxy, in which the solar system is located, in which the planet Earth is located, on which people live. Refers to spiral galaxies barred and is a member of the Local Group of galaxies along with the Andromeda Galaxy, the Triangulum Galaxy and 40 dwarf galaxies. The diameter of the Milky Way is 100,000 light years. There are about 200-400 billion stars in our galaxy. Our solar system is located on the outskirts of the galactic disk, in a relatively calm place that allowed life to arise on our planet. Perhaps we are not the only ones living in the Milky Way, but this remains to be seen. Although, in the ocean of the Universe, the entire history of mankind is nothing more than a barely noticeable ripple, it is very interesting for us to explore the Milky Way and follow the developments of events in our native galaxy.
Astronomers from the European Space Agency (ESA) have been able to more accurately calculate the approximate mass of our galaxy. It turned out that it was twice as large as the results predicted previous studies. How much? Almost doubled. The findings of a 2016 study suggested that the mass of the Milky Way could be about 750 billion solar masses. ESA specialists indicate a different figure – almost 1.5 trillion. Why such difference?
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 settlements. In our latitudes it is especially beautiful in August. IN last month 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 unusual phenomenon, the secret of which was not 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? History of discovery this phenomenon dates 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 celestial phenomenon Not only star clusters. 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. The most important discovery Herschel became the Great Plan of the Universe. This scientist observed the planets through a telescope and counted them on different areas 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 figure, 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? This (the definition of its mass is very difficult task) it is not possible to calculate. Determination of mass causes difficulties dark matter, which does not interact with electromagnetic radiation. This is why astronomers definitively cannot 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, and also 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 life cycle is already coming to an end.
This area is located in the central part of the Milky Way's core. outer space, whose weight equal to mass 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. Yes, it is typical for him large cluster 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, helped people answer this question. electromagnetic spectrum radiation. With 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
This shape has the Milky Way itself, which is in constant rotational movement. Interestingly, the speed this process depends on the distance of a particular area from the core. 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 stripe 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 education 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 contains, as a rule, low-mass and old stars, as well as dwarf galaxies and accumulations of hot gas. 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. For of this circle characteristic increased level 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. That is why on our planet for several billion years there was no global disasters, 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 for modern researchers not yet available.
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.
The starry sky has attracted people's gaze since ancient times. The best minds All peoples tried to comprehend our place in the Universe, imagine and justify its structure. Scientific progress allowed us 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 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 how 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, illegitimate son 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, in which there is a place for 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 their 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 most bright stars systems. The diameter of the disk is more than 100 thousand light years.
Structure
The galactic center is hidden 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 works either refers only to the central region with a diameter of only a few parsecs, or includes a bulge and a gas ring, believed to be the birthplace of stars. In what follows, the first version of the term will be used.
It is difficult to penetrate into the center of the Milky Way visible light: he collides with big amount cosmic dust hiding what our Galaxy looks like. Photos and images taken in 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 more mass Sun. Around this object, according to researchers, another, but less impressive in its parameters, black hole rotates. Modern knowledge about the peculiarities of the structure of space suggest 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 you dispel all cosmic dust, what the core hides from us, an amazing picture will open to our eyes. 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. Influenced 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, according to experts who have made possible occurrence 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. Stars, single or grouped, total number exceed, according to the latest data, 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 most bright point 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 North Star or Alpha Ursa Minor. She owes her popularity to her position above North Pole Earth. The luminosity of Polaris is significantly higher than Sirius (almost two thousand times brighter than the sun), but she cannot challenge Alpha's rights Canis Major 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. The highest concentration of a substance per unit volume differs neutron stars. Color characteristic 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 part of grandiose world we are.