PHYSICAL NATURE OF THE SUN

The Sun is the central body of our planetary system and the closest star to us.

The average distance of the Sun from the Earth is 149.6 * 10 6 km, its diameter is 109 times that of the Earth, and its volume is 1,300,000 times that of the Earth. Since the mass of the Sun is 1.98 * 10 33 G(333,000 Earth masses), then in accordance with its volume we find that the average density of solar matter is 1.41 g/cm 3 (0.26 of the average density of the Earth). Based on the known values ​​of the radius and mass of the Sun, it can be determined that the acceleration of gravity on its surface reaches 274 m/sec 2 , or 28 times greater than the acceleration of gravity on the Earth's surface.

The Sun rotates around its axis counterclockwise when observed from the north pole of the ecliptic, i.e. in the same direction in which all the planets revolve around it. If you look at the disk of the Sun, then its rotation occurs from the eastern edge of the disk to the western. The Sun's rotation axis is inclined to the ecliptic plane at an angle of 83°. But the Sun does not rotate like a rigid body. The sidereal rotation period of its equatorial zone is 25 days, near 60° heliographic (measured from the solar equator) latitude it is 30 days, and at the poles it reaches 35 days

When observing the Sun through a telescope, there is a noticeable weakening of its brightness towards the edges of the disk, since rays coming from the deeper and hotter parts of the Sun pass through the center of the disk.

The layer lying on the boundary of transparency of the Sun's substance and emitting visible radiation is called the photosphere. The photosphere is not uniformly bright, but exhibits a granular structure. The light grains covering the photosphere are called granules. Granules are unstable formations, the duration of their existence is about 2-3 min, and sizes range from 700 to 1400 km. On the surface of the photosphere there are dark spots and light areas called faculae. Observations of spots and faculae made it possible to establish the nature of the rotation of the Sun and determine its period.

Above the surface of the photosphere is the solar atmosphere. Its bottom layer has a thickness of about 600 km. The substance of this layer selectively absorbs light waves of such lengths that it itself is capable of emitting. During re-emission, energy is dissipated, which is the direct cause of the appearance of the main dark Fraunhofer lines in the solar spectrum.

The next layer of the solar atmosphere, the chromosphere, has a bright red color and is observed during total solar eclipses in the form of a scarlet ring covering the dark disk of the Moon. The upper boundary of the chromosphere is constantly agitated, and therefore its thickness ranges from 15,000 to 20,000 km.

Prominences are ejected from the chromosphere - fountains of hot gases, visible to the naked eye during total solar eclipses. At a speed of 250-500 km/sec they rise from the surface of the Sun to distances equal to an average of 200,000 km, and some of them reach heights of up to 1,500,000 km.

Above the chromosphere is the solar corona, visible during total solar eclipses in the form of a silver-pearl halo surrounding the Sun.

The solar corona is divided into inner and outer. The inner crown extends to a height of about 500,000 km and consists of rarefied plasma - a mixture of ions and free electrons. The color of the inner corona is similar to that of the sun, and its radiation is the light of the photosphere scattered by free electrons. The spectrum of the inner corona differs from the solar spectrum in that dark absorption lines are not observed in it, but emission lines are observed against the background of a continuous spectrum, the brightest of which belong to multiply ionized iron, nickel and some other elements. Since the plasma is very rarefied, the speed of movement of free electrons (and, accordingly, their kinetic energy) is so high that the temperature of the inner corona is estimated at about 1 million degrees.

The outer crown extends to a height of more than 2 million meters. km. It contains tiny solid particles that reflect sunlight and give it a light yellow tint.

In recent years, it has been discovered that the solar corona extends much further than previously thought. The most distant parts of the solar corona from the Sun - the supercorona - extend beyond the Earth's orbit. As it moves away from the Sun, the temperature of the supercorona gradually decreases, and at a distance from the Earth it is approximately 200,000°

The supercorona consists of individual rarefied electron clouds, “frozen” into the magnetic field of the Sun, which move from it at high speeds and, reaching the upper layers of the earth’s atmosphere, ionize and heat it, thereby influencing climate processes.

Interplanetary space in the ecliptic plane contains fine dust, producing the phenomenon of zodiacal light. This phenomenon consists of the fact that in the spring after sunset in the west or in the fall before sunrise in the east, a faint glow is sometimes observed protruding from the horizon in the form of a cone.

The spectrum of the Sun is an absorption spectrum. Against the background of a continuous bright spectrum there are numerous dark (Fraunhofer) lines. They occur when a beam of light emitted by a hot gas passes through a cooler medium formed by the same gas. In this case, in place of the bright emission line of the gas, a dark absorption line is observed.

Each chemical element has a line spectrum unique to it, so the chemical composition of a luminous body can be determined by the type of spectrum. If the substance emitting light is a chemical compound, then bands of molecules and their compounds are visible in its spectrum. By determining the wavelengths of all lines in the spectrum, it is possible to determine the chemical elements that form the radiating substance. The intensity of the spectral lines of individual elements is used to judge the number of atoms belonging to them. Therefore, spectral analysis makes it possible to study not only the qualitative, but also the quantitative composition of celestial bodies (more precisely, their atmospheres) and is the most important method of astrophysical research.

About 70 chemical elements known on Earth were found on the Sun. But basically the Sun consists of two elements:

hydrogen (about 70% by mass) and helium (about 30%). Of the other chemical elements (only 3%), the most common are nitrogen, carbon, oxygen, iron, magnesium, silicon, calcium and sodium. Some chemical elements, such as chlorine and bromine, have not yet been discovered in the Sun. The spectrum of sunspots also contains absorption bands of chemical compounds: cyanogen (CN), titanium oxide, hydroxyl (OH), hydrocarbon (CH), etc.

The sun is a tremendous source of energy, continuously dispersing light and heat in all directions. The Earth receives about 1:2000000000 of all the energy emitted by the Sun. The amount of energy received by the Earth from the Sun is determined by the value of the solar constant. The solar constant is the amount of energy received per minute 1 cm 2 surface located at the boundary of the earth's atmosphere perpendicular to the sun's rays. In terms of thermal energy, the solar constant is 2 cal/cm 2 *min, and in the system of mechanical units it is expressed by the number 1.4-10 6 erg/sec cm 2 .

The temperature of the photosphere is close to 6000°C. It emits energy almost like a completely black body, so the effective temperature of the solar surface can be determined using the Stefan-Boltzmann law:

G
de E - amount of energy in ergs emitted in 1 sec. 1 cm 2 solar surface; =5.73 10 -5 erg/sec* deg^4 cm 2 - a constant established from experience, and T - absolute temperature in degrees Kelvin.

The amount of energy passing through the surface of a sphere with a radius of 1 A. e. (150 10" cm), equals e=4*10 33 erg/sec* cm 2 . This energy is emitted by the entire surface of the Sun, therefore, by dividing its value by the area of ​​the solar surface, we can determine the value E and calculate the temperature of the surface of the Sun. It turns out E=5800°K.

There are other methods for determining the temperature of the surface of the Sun, but they all differ in the results of their application, since the Sun does not radiate exactly like a completely black body.

Direct determination of the temperature of the inner parts of the Sun is impossible, but as it approaches its center it should increase rapidly. The temperature at the center of the Sun is calculated theoretically from the condition of pressure equilibrium and equality of energy input and expenditure at each point in the volume of the Sun. According to modern data, it reaches 13 million degrees.

Under the temperature conditions found on the Sun, all its matter is in a gaseous state. Since the Sun is in thermal equilibrium, at each point the force of gravity directed towards the center and the forces of gas and light pressure directed from the center must be compensated.

The high temperature and high pressure in the interior of the Sun cause multiple ionization of the atoms of the substance and its significant density, probably exceeding 100 g/cm 3 , although even under these conditions the substance of the Sun retains the properties of a gas. Numerous data lead to the conclusion that for many millions of years the temperature of the Sun remains unchanged, despite the large energy consumption caused by solar radiation.

The main source of solar energy is nuclear reactions. One of the most likely nuclear reactions, called proton-proton, involves the conversion of four hydrogen nuclei (protons) into a helium nucleus. During nuclear transformations, a large amount of energy is released, which penetrates the solar surface and is emitted into space.

The radiation energy can be calculated using the famous Einstein formula: E = ts 2 , Where E - energy; T - mass and c - the speed of light in vacuum. The mass of the hydrogen nucleus is 1.008 (atomic mass units), so the mass of 4 protons is 4 1.008 = 4.032 A. eat. The mass of the resulting helium nucleus is 4.004 A. eat. Reduction in hydrogen mass by 0.028 A. eat.(this is 5 * 10 -26 g) leads to the release of energy equal to:

ABOUT
The total radiation power of the Sun is 5 * 10 23 liters. With. Due to radiation, the Sun loses 4 million. T substances per second.

At the moment, there is no satisfactory theory of the origin and evolution of galaxies. There are several competing hypotheses to explain this phenomenon, but each has its own serious problems. According to the inflation hypothesis, after the appearance of the first stars in the Universe, the process of their gravitational unification into clusters and then into galaxies began. Recently, this theory has been called into question. Modern telescopes are able to “look” so far that they see objects that existed approximately 400 thousand years after the Big Bang. It was discovered that at that time fully formed galaxies already existed. It is assumed that too little time passed between the emergence of the first stars and the above-mentioned period of development of the Universe, and according to the Big Bang theory, galaxies simply would not have had time to form.

Another common hypothesis is that quantum fluctuations constantly occur in a vacuum. They also occurred at the very beginning of the existence of the Universe, when the process of inflationary expansion of the Universe, expansion at superluminal speed, was underway. This means that the quantum fluctuations themselves expanded, and to sizes that were perhaps many, many times larger than their initial size. Those of them that existed at the moment of the cessation of inflation remained “inflated” and thus turned out to be the first gravitating inhomogeneities in the Universe. It turns out that matter had about 400 thousand years to undergo gravitational compression around these irregularities and form gas nebulae. And then the process of the emergence of stars and the transformation of nebulae into galaxies began.

Astronomers associate the formation of stars with the condensation of a diffuse rarefied gas-dust medium in the interstellar medium. In 1939, it was established that the source of stellar energy is thermonuclear fusion occurring in the bowels of stars. In their depths, four protons combine through a series of intermediate stages into one alpha particle (helium nucleus). Every year at least one star “dies” in the Galaxy as its supply of nuclear fuel runs out. This means that in order for the star tribe not to degenerate, it is necessary that the same number of stars be formed in our Galaxy. In order for the Galaxy to maintain unchanged the distribution of stars according to luminosity classes, temperature, incl. according to spectral types, it is necessary that it automatically maintains a dynamic balance between emerging and dying stars. In the Galaxy, the lifetime of a star with a mass less than that of the Sun is longer than that of a larger star, since thermonuclear processes proceed faster at higher pressure and higher temperature. The greater the mass of a star, the less it exists as a star - the less it lives.

Modern astronomy has a large number of arguments in favor of the formation of stars through the condensation of clouds of gas and dust in the interstellar medium. Therefore, the number of stars in the arms of galaxies is greater than in the spaces between the arms, and the glow of stars in the arms is brighter; supernova explosions often occur there. It is assumed that a supernova explosion is associated with the fact that helium begins to “burn” on it; as a result of thermonuclear fusion, carbon nuclei are formed from helium nuclei. During a helium reaction, more thermonuclear energy is released than during a hydrogen reaction. Such a star literally explodes, throwing off part of its atmosphere consisting of hydrogen.

It takes relatively little time for protostars to go through the earliest stages of evolution. If, for example, the mass of the protostar is greater than the Sun, it takes only a few million years, and if less, then several hundred million years. Since the evolutionary time of protostars is relatively short, this earliest phase of stellar development is very difficult to detect. At this first stage of evolution, the protostar collects hydrogen gas and dust from galactic clouds, causing its mass to increase, the hydrogen atmosphere to become more powerful, and the pressure in the lower layer of the protostar's atmosphere to increase. Finally, the pressure of the atmosphere and its temperature on the protostar become such that the thermonuclear reaction of fusion of helium from hydrogen begins. At this moment the protostar turns into a star. It stops contracting, although it continues to capture hydrogen from the galactic clouds. Its volume and radiation are supported by thermonuclear reactions occurring in the lower regions of the atmosphere.

The time of equilibrium glow of a star is determined by its initial mass and the supply of hydrogen from the surrounding space. If the supply of hydrogen to a star increases, then it flares up brighter; if the flow of hydrogen decreases, then the glow of the star decreases until it stops completely, and the star fades. But if the supply of hydrogen increases again, then the star can flare up again, and helium is again synthesized in its atmosphere, which accumulates in the lower layers of the star’s atmosphere. If a lot of helium nuclei accumulate, then the pressure and temperature in the lower layer of the helium atmosphere will reach such a value that the synthesis of carbon nuclei from helium nuclei will begin. In this case, so much energy will be released that an explosion will occur, the transition of the star from hydrogen to helium fuel will cause a supernova explosion. In this case, a significant amount of hydrogen will be released into the surrounding space. A spherical cloud will form around the helium star - a bubble, in the center of which a bright helium star will radiate energy.

Hydrogen burns out, and its influx is weakened, as the star enters the interarm space of the galaxy. Sooner or later, if there is insufficient supply from the outside, almost all of the hydrogen on the star will burn out, or rather, there will still be a lot of it left, but the pressure and temperature in the thermonuclear reaction zone will decrease, and the reaction will stop. In this case, the star will simply go out. The cooling atmosphere will begin to compress under the influence of gravitational forces that are not balanced by the release of thermal energy. When compressed, the temperature of the remaining hydrogen and helium will increase, forming a very dense hot region consisting of helium with a small admixture of heavier elements. In this dense hot region, nuclear reactions will not occur, but they will proceed quite intensely at the periphery of the star’s core - in a relatively thin layer. The star's luminosity and size will begin to grow again. At the same time, the star will swell and begin to turn into a red giant.

After the temperature of the contracting dense helium core of a red giant star reaches 100–150 million degrees Kelvin, a new nuclear reaction will begin to take place there: the formation of a carbon nucleus from three helium nuclei. As soon as this reaction begins, the compression of the star's atmosphere will stop again.

When a star explodes, it sheds a significant portion of its atmosphere; this process is called the formation of planetary nebulae. When the outer shell of a star separates, its inner, very hot layers are exposed. In this case, the ejected shell will expand, flying further and further from the star. Such phenomena have been discovered in space and captured in photographs.

The powerful ultraviolet radiation of the star - the core of the planetary nebula - will ionize the atoms in the ejected shell, exciting their glow. The spectrum of this glow is related to the atomic composition of the planetary nebula. After a few tens of thousands of years, the shell around the star will dissipate, and only a small, very hot, dense star will remain. Gradually, slowly cooling, it will turn into a white dwarf, which will eventually become a black dwarf - a superplanet with a very high density. Black dwarfs are “dead”, cooled bodies of very high density; they are millions of times denser than water. Their sizes may be smaller than the size of the globe, although their masses are comparable to the solar mass. The cooling process of white dwarfs lasts many hundreds of millions of years. This is apparently how most stars die.

Thus, white dwarfs seem to mature inside the stars of red giants and are born after the separation of the outer layers of the atmosphere of giant red stars. In other cases, the shedding of the outer layers may occur not through the formation of planetary nebulae, but through the gradual outflow of atoms. One way or another, white dwarfs, in which the nuclear reactions of the synthesis of helium from hydrogen have stopped, shine due to the reaction of the synthesis of carbon from helium. White dwarfs gradually reduce their luminosity as they use up their helium reserves and become invisible black dwarfs. The fact is that in the space of galaxies, helium stars cannot replenish the supply of their nuclear fuel - helium. It is simply not there, or there is very, very little of it.

The process of star formation from the interstellar gas-dust medium also occurred in our Galaxy, it occurs continuously.

During the process of evolution, a star returns a significant portion of its mass to interstellar space, first in the form of radiation and stellar wind from hot plasma, and then as a result of the formation of a planetary nebula. From matter, including plasma and gas ejected by a star, new young stars will again form in Space, which in turn will go through the same stages of development and turn into black dwarfs. In a word, the circulation of matter - matter and energy - occurs through stars in galaxies.

Scientists began to take a serious approach to the problem of galaxy evolution in the mid-1940s. These years were marked by a number of important discoveries in stellar astronomy. It was possible to find out that among star clusters, open and globular, there are young and old, and scientists were even able to estimate their age. It was necessary to carry out a kind of population census in galaxies of different types and compare the results. In which galaxies (elliptical or spiral), in which classes of galaxies are younger or older stars predominant. Such a study would give a clear indication of the direction of evolution of galaxies and would make it possible to clarify the evolutionary meaning of the Hubble classification of galaxies.

Such strange objects sometimes fall into the Hubble lens. This object even resembles an artificial (technical) structure. In fact, this is most likely something formed by a black hole, around which bright stars rotate in one circular orbit in the form of a “round dance” - they together form a ring of fire, and two stars rotate around it in elliptical orbits at enormous speeds larger radius. At the same time, these two stars leave a trail of hot gas or plasma escaping from their atmospheres.

Elliptical galaxy ESO 325-G004 in the Abell_S740 galaxy cluster.

Cluster of galaxies. In the foreground is a system of three gravitationally bound interacting (and most likely colliding) galaxies. Two slightly curved arms extend from this “tri-core” galaxy. I think that all the galaxies in this cluster are gravitationally connected to each other and form one of the nodes in the structure of the Metagalaxy. But there will be a special chapter and page on our website about the structure and life of the Metagalaxy.

It is almost impossible to imagine this galaxy as the result of a collision of four galaxies. But if we assume that visible galaxies are the product of black holes gravitationally connected to each other, then we can assume that such a complex formation could arise as a result of the ejection of protostars from four black holes connected to each other in the gravitational system. Each of these black holes forms its own spiral disk.

But first, astronomers needed to figure out the numerical relationship between different types of galaxies. Direct study of photographs taken at the Mount Wilson Observatory allowed Hubble to obtain the following results: elliptical galaxies - 23%, spiral galaxies - 59%, barred spirals - 15%, irregular - 3%. However, in 1948, astronomer Yu.I. Efremov processed the data from the Shapley and Ames galaxy catalog and came to the following conclusions: elliptical galaxies are on average 4 magnitudes fainter than spiral galaxies in absolute magnitude. Among them there are many dwarf galaxies. If we take this circumstance into account and recalculate the number of galaxies per unit volume, it turns out that there are approximately 100 times more elliptical galaxies than spiral ones.

Most spiral galaxies are giant galaxies, most elliptical galaxies are dwarf galaxies. Of course, among both there is a certain spread in size; there are elliptical giant galaxies and spiral dwarfs, but there are very few of both.

In 1947, H. Shapley drew attention to the fact that the number of bright supergiants gradually decreases as we move from irregular galaxies to spiral ones, and then to elliptical ones. It turned out that it was the irregular galaxies and galaxies with highly branched branches that were young. Shapley then expressed the idea that the transition of galaxies from one class to another does not necessarily occur. It is possible that the galaxies were all formed as we see them, and then only slowly evolved in the direction of smoothing and rounding their shapes. There is probably no unidirectional change in galaxies.

H. Shapley drew attention to another important circumstance. Double galaxies are not the result of one galaxy colliding and being captured by another. Spiral galaxies often coexist in such pairs with elliptical ones. Such galactic pairs, in all likelihood, arose together. In this case, it is impossible to assume that they have gone through a significantly different development path.

In 1949 B.V. Kukarkin drew attention to the existence of not only paired galaxies, but also clusters of galaxies. Meanwhile, the age of a galaxy cluster, judging by celestial mechanics data, cannot exceed 10–12 billion years. Thus, it turned out that galaxies of different shapes formed almost simultaneously in the Metagalaxy. This means that the transition of each galaxy during its existence from one type to another is completely unnecessary.

Possible options for the dynamics of stars in galaxies. Depending on the size of the protostar and the density of the gas cloud surrounding it, different types of stars are formed with different fates. By gathering a powerful atmosphere of hydrogen, the star can become a giant star that abruptly switches from a hydrogen fusion source to a helium source, shedding its shell of unused hydrogen. But it can come to a supernova explosion through the red giant stage. A third type of dynamics is also possible, when a small hydrogen star falls into a dense hydrogen cloud and receives hydrogen recharge from it, prolonging its life. Photo from the site: http://900igr.net

V.B. Kurakin in 1949 drew attention to the existence of galaxy clusters in the Universe.

Galaxy clusters are gravitationally bound systems of galaxies, some of the largest structures in the Universe. The size of galaxy clusters can reach 10 trillion light years. Clusters are conventionally divided into two types. Regular– clusters of regular spherical shape, in which elliptical and lenticular galaxies predominate, with a clearly defined central part. At the centers of such clusters are giant elliptical galaxies. An example of a regular cluster is the cluster behind the constellation Coma Berenices. Irregular- clusters without a definite shape, inferior in number of galaxies to regular ones. Clusters of this type are dominated by spiral galaxies. An example is the cluster behind the constellation Virgo. The masses of the clusters exceed 10 trillion solar masses.

Boris Vasilievich Kukarkin (1909–1977) – Soviet astronomer. Photo from the site: http://space-memorial.narod.ru The elliptical galaxy in the photo on the right is gigantic in size. Between it and the observer there is a twin small spiral galaxy with two well-defined nuclei. At the center of an elliptical galaxy there is a vast core. In all likelihood, there is a black hole there; it concentrates gas around itself and absorbs it. However, this object does not rotate and therefore does not have the shape of a disk. The bright and not so bright stars in this photo are located in our Galaxy. The stars in an elliptical galaxy are indistinguishable, or perhaps they are not there at all.

Cosmogonic concepts of A.I. Lebedinsky and L.E. Gurevich

Creating his hypothesis, A.I. Lebedinsky proceeded from the following basic assumptions: 1 – galaxies were formed from rarefied diffuse matter that filled (and fills) the Metagalaxy; 2 – galaxies did not arise simultaneously, so that some of them were formed when others already existed; 3 – conditions in metagalactic space during the formation of galaxies differed little from modern ones. The mass of gas from which the galaxy was formed, A.I. Lebedinsky called it a protogalaxy. He believed that before the compression began, the state of the protogalaxy was quasi-static, that is, almost unchanged. Then some gradual quantitative changes in the state of the protogalaxy (for example, an increase in density) led to the fact that it began to shrink. This could also be facilitated by the energy loss of gas molecules upon collision with solid dust particles.

Further, the compression of the protogalaxy occurs almost according to Jeans: initially, the spherical nebula rotates and flattens, and as it contracts, it begins to rotate faster and faster, which leads to its flattening, which is not limited by anything. But a protogalaxy is not an elliptical nebula at all, since there are no stars in it, and we cannot notice it.

But at a certain stage of compression and flattening, condensations appear in the protogalaxy, first large, thousands of light years in diameter, then smaller and smaller. The largest ones will then give rise to star clouds, the smaller ones will give rise to star clusters, and even smaller ones will give rise to stars. Star formation occurs through gravitational condensation. Stars appear in the most flattened spiral galaxies. Spiral branches arise because in highly flattened systems this is energetically favorable. With a small flattening - such as in elliptical galaxies - the formation of spirals and stars is impossible.

Astrophysicist Alexander Ignatievich Lebedinsky. Photo from the site: http://slovari.yandex.ru/ The theory of the further evolution of a young spiral galaxy by A.I. Lebedinsky developed together with L.E. Gurevich. They showed that with the formation of stars in the galaxy, a redistribution of angular momentum begins, which is carried out with small masses. The system is divided into a central part, the core, and a peripheral, highly flattened part. Further, the gravitational interactions of the stars lead to a gradual increase in the deviation of their movements from circular and to their swing in the direction perpendicular to the equator of the galaxy. The galaxy continues to shrink in the direction of its radii, but expands along its axis, causing its flattening to decrease somewhat. Stars are scattered from the central part of the galaxy in all directions. In this case, a spherical subsystem is formed. And in the flat subsystem, the formation of young stars from diffuse matter continues. Gravitational interactions will destroy star clusters and associations, then star clouds and spiral branches will disintegrate. Spiral galaxy, according to L.E. Gurevich and A.I. Lebedinsky, at the end of evolution it should turn into elliptical. Due to the exhaustion of diffuse matter, star formation should cease.

This theory explained many problems, such as the formation of interstellar magnetic fields and magnetic fields near stars, the processes of acceleration of charged particles, and the formation of complex structural elements. Cosmogonic concept of A.I. Lebedinsky and L.E. Gurevich's theory was an important stage in the development of galactic cosmogony, but it also has weaknesses. Firstly, it postulated the existence of protogalaxies that had not been observed by anyone (either before or since). Secondly, the authors of the hypothesis did not provide an explanation for the spiral structure of galaxies, limiting themselves to a remark about the energetic advantage of this structure. Discussion of this issue by A.I. Lebedinsky promised to carry out the second part of his work. Alas, neither he nor L.E. Gurevich never did this, and the second part of the work was not published.

Work on this problem was continued in 1958 by the Leningrad theorist T.A. Agekyan. Having studied the evolution of rotating systems of mutually attracting bodies in the form of equilibrium figures, T.A. Agekyan took into account the possibility of their dissipation, that is, individual stars leaving the system.

By measuring the speed at which neighboring stars move away from each other, astrophysicists have found that stars belonging to the same group often move as if they were ejected from the same point in outer space. This is quite consistent with my hypothesis of the formation of stellar cores as a result of explosions in black holes. Having collected hydrogen atmospheres around themselves, these fragmentarians new stars flare up. More recently, astronomers L.E. Gurevich and A.I. Lebedinsky created a theory of the formation of so-called new stars. Before this, astronomers believed that every star must necessarily go through the “nova” stage - flash into an unusually bright supernova for a short time. According to the theory of L.E. Gurevich and A.I. Lebedinsky, not every star can become a “supernova”. In order for a star to flare up, its interior must have very high temperature and pressure. Guided by their theory, they predicted a “supernova” explosion in the constellation Corona Borealis, and this explosion actually occurred. Drawing from the site: http://russkoe-pervenstvo.narod.ru

Lev Emmanuilovich Gurevich (1904–1990). The range of his creativity was very wide: problems of physical kinetics, molecular physics, plasma physics. Photo from the site: http://www.lomonosov-fund.ru/ Tateos Artemyevich Agekyan (1913–2006). Soviet astronomer , Honored Scientist of the Russian Federation.

Big Bang theory (hypothesis)

All hypotheses trying to explain the origin of galaxies use as an axiom the theory of the Big Bang, as a result of which the Universe was formed. According to this theory, the entire Universe was formed as a result of an explosion: first, a hot “gas” was formed from elementary particles, which, cooling during the expansion of the Universe, formed structures: atomic nuclei, atoms, molecules; clouds of this gas were then compressed by gravity into galaxies and stars. For some reason, no special attention is paid to the fact that such a Big Bang hypothesis leads to absurd conclusions about the finitude of the Universe. It seems that this hypothesis, which they hastened to call a theory, simply blinded the minds of most astronomers and astrophysicists.

So what does the Big Bang hypothesis say? During the era of radiation (according to this hypothesis, in the beginning there was light!), the rapid expansion of cosmic matter continued, consisting of photons, among which there were free protons and electrons, and extremely rarely - alpha particles. There were a billion times more photons than protons and electrons. During the radiation era, protons and electrons remained largely unchanged, only their speed decreased. With photons the situation was much more complicated. Although their speed remained the same, during the radiation era gamma photons gradually turned into x-ray photons, ultraviolet photons and photons of light. By the end of this era, matter and photons had cooled down so much that each proton could be joined by one electron. In this case, one ultraviolet photon or several photons of visible light were emitted. This is how the hydrogen atom was formed and this is how the hydrogen Universe arose. This was the first particle system in the Universe. With the emergence of hydrogen atoms, the stellar era began - the era of protons and electrons.

Next, the Universe entered the stellar age in the form of hydrogen gas with a huge number of light and ultraviolet photons. Hydrogen gas expanded in different parts of the Universe at different rates. Its density was also unequal. It formed huge clumps - many millions of light years long. The mass of such cosmic hydrogen clumps was hundreds of thousands, or even millions of times greater than the mass of our present Galaxy. The expansion of gas inside the clumps was slower than the expansion of rarefied hydrogen between the clumps themselves. Later, supergalaxies and clusters of galaxies were formed from individual areas with the help of their own gravity. Thus, the largest structural units of the Universe - supergalaxies - are the result of the uneven distribution of hydrogen, which occurred in the early stages of the history of the Universe.

Colossal hydrogen concentrations are the embryos of galaxy clusters: according to the hypothesis, they rotated slowly. Vortexes similar to whirlpools formed inside them. The diameter of these cosmic vortices reached approximately one hundred thousand light years. This is how systems were formed - protogalaxies, i.e. embryos of galaxies. Despite their incredible size, the vortices of protogalaxies were only an insignificant part of supergalaxies and did not exceed one thousandth of a supergalaxy in size. The force of gravity formed from these vortices systems of stars, which we call galaxies.

Under the influence of gravity, the rotating vortex was compressed into a ball or (from rotation) into a somewhat flattened ellipsoid. The dimensions of such a regular giant hydrogen cloud ranged from several tens to several hundred thousand light years. If the energy of the gravitational forces that held the atom in the protogalaxy at its periphery exceeded its kinetic energy, the atom became an integral part of the galaxy; if not, it left it. This condition is called the Jeans criterion. With its help, you can determine to what extent the mass and size of the protogalaxy depends on the density and temperature of the hydrogen gas. The colder the cloud was, the more atoms remained in it.

A protogalaxy that did not rotate became the ancestor of a spherical galaxy. Oblate elliptical galaxies were born from slowly rotating protogalaxies. Due to insufficient centrifugal force, gravitational force prevailed in them. The protogalaxy contracted, and the density of hydrogen in it increased. As soon as the density reached a certain level, clumps of hydrogen atoms began to be released and compressed, from which protostars were born, which later evolved into stars. The birth of all the stars in a spherical or slightly flattened galaxy occurred almost simultaneously. This process continues for a relatively short time, about one hundred million years. This means that in elliptical galaxies all the stars are approximately the same age and are very old. In elliptical galaxies, all hydrogen was used up immediately at the very beginning of star formation. Over the subsequent time, stars could no longer appear in elliptical galaxies. Thus, in elliptical galaxies the amount of interstellar matter should be negligible.

Spiral galaxies, according to the Big Bang hypothesis, consist of an old spherical component (which is similar to elliptical galaxies) and a younger flat component, which includes spiral arms. Between these components there are several transitional components of different levels of oblateness, different ages and speeds of rotation. Spiral galaxies rotate much faster than elliptical galaxies because they formed from rapidly rotating vortices in the early Universe. Therefore, both gravitational and centrifugal forces participated in the creation of spiral galaxies.

Each atom of interstellar gas was subject to two forces: gravity, which pulled it toward the center of the galaxy, and centrifugal force, which pushed it away from the axis of rotation. Ultimately, the gas was compressed towards the galactic plane. Currently, interstellar gas is concentrated in the galactic plane into a very thin layer. It is concentrated primarily in the spiral arms and represents a flat, or intermediate component, called the “type II stellar population.” At each stage of the flattening of interstellar gas, stars were born in an increasingly thinner disk.

This theory-hypothesis, at first glance, looks very convincing, especially when supported by a fair number of mathematical formulas. But the devil, as usual, hides not in the formulas, but in the initial assumptions accepted as axioms. And one of the axioms is the unproven recognition as a fact of the assumption that the gas cloud will begin to rotate on its own, and at the same time still compress towards the center. The gravitational interaction of hydrogen atoms with each other is so insignificant that they can “stick together” into a lump only at absolute zero degrees Kelvin - i.e. with complete cessation of thermal movement. In order for hydrogen gas to begin to compress, a powerful source of gravity is needed.

The hypothesis of secular evolution of galaxies

It is necessary to clarify the meaning of the term “secularization”. To a first approximation, secularization is separation (division), the acquisition of independence. The term “secularization” was first used in 1646 by Longueville during the negotiations preceding the Peace of Westphalia, and meant the possibility of satisfying the interests of the victors through the confiscation of monastic possessions. Secularization (seizure) of church property was practiced by European monarchs, and in Russia it was quite widely used by Peter I and Catherine II.

In the 17th century The secularization of science from religion began, the principle of separation of reason and faith, secular and spiritual principles was formulated. The independence of the secular principle is clearly manifested not only in the political and scientific thought of that era, but also in ethics, which is beginning to be viewed as a secular rather than a religious science. Until now, with varying success, there is a struggle to actually separate the church from the state, and the school from the church.

Elliptical galaxies, unlike spiral galaxies, have always been considered single-component star systems. All the stars of an elliptical galaxy seem to be similar to each other, have the same age, the same metallicity and are distributed in a three-dimensional spheroidal structure, which, when projected onto the plane of the sky, can have an apparent axial ratio from 1: 1 to 1: 3. Most elliptical galaxies rotate slowly ( compared to disk galaxies). The stars in such galaxies move chaotically, like specks of dust in the air when there is no wind. This is proven by the high dispersion of their speeds and directions of movement. However, recently some interesting things have come to light.

In 1988, kinematically distinct nuclei were discovered in some elliptical galaxies, which rotated much faster than the entire galaxy. In the vast majority of elliptical galaxies of moderate luminosity, “disc-shaped” isophotes around the central part were recorded. D. Burstein said about this: “Inside absolutely all elliptical galaxies there are small disks.” The disks discovered in the centers of elliptical galaxies are also distinguished by their chemical composition - they contain more heavy atoms.

Spiral galaxy NGC 4826. From the appearance of the galaxy, no one could assume that the outer gas of the disk rotates towards the stars. Photo by J. Glissen (Whale Peak Observatory) taken from the site: http://student.km.ru

The hypothesis of secular evolution of galaxies states that gas “flows” into the centers of galaxies. D. Friedli and W. Benz (1993) believe that if the gas initially rotated in the same direction as the stars, then this stimulates star formation in the galactic core, and if the gas “counter-rotated”, that is, rotated towards the stars, then it In the process of flowing towards the center, it leaves the plane of the galaxy and stabilizes in a rotating, highly inclined circumnuclear ring, without reaching the very center of the galaxy. But where does the gas that rotates towards the stars come from? Astronomers believe that the supply of counter-rotating gas is possible during the slow merger of galaxies. For example, the origin of the thick stellar disk in our Galaxy is associated with a minor merger - the absorption of its satellite by the Galaxy. Galaxies with large gaseous disks rotating opposite to the rotation of the stars are also known in the immediate vicinity of our Local Group of galaxies, for example, in the spiral galaxy NGC 4826, all the gas simultaneously changes the direction of rotation at a distance of 1 kpc from the center.

In the five closest galaxies, inner polar rings of ionized gas were discovered: here, within a few hundred parsecs from the center of the galaxies, the gas rotates in a plane generally perpendicular to the plane of rotation of the stars. This is a completely unexpected discovery.

In all likelihood, globular galaxies are the youngest galaxies. In them, the black hole in the center still rotates very slowly and it has not entrained the surrounding gas and dust into a circular motion, perhaps because the mass of this black hole is not large enough..

As the central heavy core (black hole) in a spherical galaxy absorbs dust and hydrogen, it begins to rotate faster and faster, dragging the entire spherical cloud into this rotation, causing the cloud to begin to flatten. When a critical mass is reached, the black hole begins to eject fragments - clumps of superdense matter, which, by inertia, fly away from the center of the galaxy and remain in orbit around it. In this case, fragmentaries, having high gravity, collect some of the gas and dust from the galactic arms. Some of the fragments become black holes, since their mass and density are very high. Others become stars, others become planets and satellites of planets.

Ideas about the paths of formation and evolution of galaxies have changed dramatically over the past 20 years. Astronomers and astrophysicists have realized that it is likely that galaxies “form,” that is, form and change structure throughout their lives. Previously, they believed that galaxies first form and then evolve. Why has the paradigm changed so much?

While astronomers were slowly observing and studying galaxies, cosmologists, from theoretical considerations, came to the conclusion that all gravity and, consequently, the dynamic evolution of the Universe is determined by non-baryonic cold dark matter, which begins to “clump” under the influence of gravitational instability, that is, to disintegrate into small clumps, which then merge into large ones, then into very large ones, and so on... And the baryonic fraction (gas, mainly hydrogen), whose mass is only 10%, is obliged to follow the dark matter and also fragment and merge, merge, merge... Stars are formed “along the way,” in the process of merging structures. Thus, from the depths of cosmological inferences emerged a hierarchical concept of the formation of galaxies.

Early work by cosmologists argued that small spiral galaxies were born first, and giant elliptical galaxies appeared last - no more than 5 billion years ago, as a result of the merger of small spiral galaxies. In the first billion years of the life of the Universe, formed as a result of the Big Bang, galaxies with a mass of no more than 10 to the 8th power M¤ could be formed; in the first 6 billion years of the life of the Universe, galaxies with a mass of no more than 10 to the 10th power M could be formed ¤, and all the more massive ones formed even earlier. But observers using new giant telescopes have found quite a lot of massive galaxies, with a mass of stellar matter greater than 10 to the 11th power M¤, formed much earlier than 6 billion years ago. It turned out that the population of giant elliptical galaxies, both in clusters and in rarefied surroundings, formed ~ 8 billion years ago. After this, cosmologists became less categorical, but the hierarchical concept of galaxy formation still continues to dominate.

The galaxy continues to evolve constantly and under the influence of instabilities, both generated externally, by gravitational interaction with its neighbors, and under the influence of internal 4 factors inherent in even completely isolated galaxies. This “quiet” evolution of galaxies throughout their entire life is called secular. Although it is calm, it can also lead to very significant changes in the structure.

Let us consider in detail the main mechanisms of the structural evolution of galaxies: internal - gravitational instabilities of thin cold disks (both stellar and gaseous); external - tidal interactions (also gravitational in nature), large and small mergers.

The models of D. Friedley and W. Benz (1993, 1995) have an interesting feature: gas can reach the center of the galaxy only if it initially rotated in the same way as the stars. And if the gas rotates in the other direction, then in the process of flowing towards the center of the galaxy it leaves the plane of the disk and forms a stable inclined ring.

When galaxies interact closely, tidal structures appear in them - “bridges”, “tails”, extended spiral arms, “pulled” by the gravity of the disturbing object from the disk of the galaxy involved in the interaction. It also turned out that external gravitational influence transforms not only the outer parts of galaxies: a bar appears in the inner regions of the disk. But eventually all the gas will fall into the center of the galaxy, followed by a massive burst of star formation.

If a gas protogalactic cloud evolves alone, then only a disk galaxy can form from it, since in this case the galaxy has nowhere to put the extra angular momentum of the gas. This was one of the biggest problems for the classical theories of galaxy formation by "monolithic collapse" that developed in the 1970s.

In small mergers, a small satellite galaxy with a mass of, for example, 10% of the mass of the large galaxy falls onto a large disk galaxy. Calculations show that when falling, even at an angle to the plane of the main disk, the satellite, after several impacts on it, loses the vertical component of its momentum, settles in the plane of the large disk and begins to “spiral” towards its center. Over the course of about 1 billion years, it reaches the center of the host galaxy, losing a smaller part of its own matter along the way. What does the satellite galaxy bring to the center? Most of its stars and gas, if it initially had it. If initially there was no gas in the small galaxy, still, as a result of the collision, it strongly disturbed the gas disk of the large galaxy, causing turbulence to intensify and, consequently, viscosity in the global gas disk to increase. An increase in viscosity means an intense redistribution of the torque and again rapid radial gas flows towards the center. Small mergers should also lead to a concentration of gas in the galactic core and a subsequent burst of star formation.

The mechanisms of secular evolution of galaxies lead to the concentration of gas in their centers and, as a consequence, to a probable outbreak of star formation in these centers. The newly formed stars in the center of the galaxy will most likely be distributed in a compact circumnuclear stellar disk. And if we want to find the consequences of their secular evolution in galaxies close to us, it is most reasonable to look in the centers of these galaxies for compact stellar disks that differ from their surroundings (the bulge, for example) in their younger age and higher metal content, since they were formed later from well-evolved matter . But the first impressive discoveries of circumnuclear stellar disks were made in elliptical galaxies, where no one expected to find them.

Numerical modeling shows that over a period of about a billion years, most of the gas of an evolving isolated galactic disk accumulates in its center, within a radius of about 1 kpc, while high densities arise in the center, and vigorous star formation occurs in them.

Nuclei in galaxies are also distinguished chemically by the increased content of heavy atoms (Silchenko O.K., Afanasyev V.L., Vlasyuk V.V. Astronomical Journal, 1992, v. 69, p. 1121). In 7 of the 12 galaxies studied by these authors, chemically isolated nuclei were discovered. Among these galaxies with chemically isolated nuclei were one elliptical, three lenticular and three spiral galaxies. Later, the same authors managed to discover several dozen galaxies with chemically isolated nuclei. The difference in the average ages of nuclei in galaxies in dense and rarefied environments can be explained by the fact that in dense environments the nuclear burst of star formation proceeded more efficiently and ended in a shorter time than in the nuclei of isolated galaxies.

All mechanisms of secular evolution of galaxies lead to the “draining” of gas into the center of the galaxy. But does this clearly imply an outbreak of star formation in the center of the galaxy? D. Fridley and W. Benz (1993) answer: no, only if the gas initially rotated in the same direction as the stars. And if the gas was “counter-rotating”, that is, rotating towards the stars, then in the process of flowing towards the center it leaves the plane of the galaxy and stabilizes in a rotating, highly inclined circumnuclear ring, without reaching the very center of the galaxy.

All dynamic processes of restructuring galaxies lead to a concentration of gas in their centers. By studying the central regions of nearby galaxies, even with the help of relatively modest observational means that are still available to Russian astronomers, it is possible to restore the complete evolutionary history of visible matter in the Universe and say whether cosmologists are right in constructing such a beautiful, but not yet fully confirmed, scheme as the hierarchical galaxy formation concept.

Hypothesis V.A. Ambartsumyan

V.A. Ambartsumyan and his students showed that star formation in galaxies continues in our time. Therefore, spiral and irregular galaxies may abound in young stars not because these galaxies themselves are young, but because they have conditions for star formation, whereas elliptical galaxies do not.

B.V. Kukarkin noted that in not a single elliptical galaxy, even the most compressed, has interstellar diffuse matter concentrated in the equatorial plane been discovered. The diffuse inclusions found in them are concentrated towards the center of these galaxies. On the contrary, all spiral galaxies are rich in interstellar diffuse matter concentrated in the equatorial plane, which is especially clearly visible when the galaxy is seen edge-on.

Spiral galaxies are different: large and smaller, and sometimes very small (on a cosmic scale). Some of them, relative to us, observers, are twisted to the right, others – to the left. Galaxies have cores, arms, and inter-arm spaces. Galaxies consist of massive cosmic bodies - stars, planets and black holes, as well as clouds of gas and dust.

The ring galaxy is a Hoag object. This photograph shows several galaxies much further away from Hoag's object. Photo from the site: http://kapuchin.livejournal.com/191347.html The core of this galaxy will soon stop receiving hydrogen from the space of the Metagalaxy. All hydrogen is now intercepted by a ring of gas and dust, “stuffed” with stars, planets and secondary black holes.

In 1950, Art Hoag discovered an unusual extragalactic object. In its outer part there is a ring dominated by bright blue stars, and in the center there is a ball of white and yellow stars. Between them is a gap that appears almost completely dark. Hoag's object has a diameter of about 100,000 light-years and lies about 600 million light-years away beyond the constellation Serpens. Several similar objects have now been discovered; they are considered one of the forms of ring-shaped galaxies. The reason for their appearance could be a collision of galaxies and a disturbing gravitational effect on an ordinary spiral galaxy of a core with an unusual shape and unusual properties. The photo on the left was taken by the Hubble Space Telescope in 2001 (R. Lucas. Hubble Heritage Team, NASA). It can be assumed that at first this galaxy developed according to the usual scenario: the black hole gathered a huge gas cloud around itself, spun it into a spiral, then clumps of superdense matter began to be ejected from it - fragments, which eventually entered orbit around the black hole - the center of the Galaxy . But at some stage the activity of the core of this galaxy sharply decreased. The black hole at its center continued to absorb matter, which emits light before falling into this hole and becoming invisible. But the outer arms, under the influence of the attraction of the “calmed” core of the galaxy, formed a ring in which traces of the former spiral structure are still visible. In all likelihood, this ring does not fall on the core because it rotates very quickly around the core. More precisely, the stars and fragments that make up this ring rotate, and the gas and dust bound by the gravity of these stars also rotate with them, which is why they do not fall onto the galactic core. In all likelihood, ring galaxies are located in those parts of the Metagalaxy in which the concentration of gas and dust is extremely low.

Beyond the constellation Centaurus, 12 million light-years away, lies the lenticular galaxy Centaurus A (NGC 5128). After the Magellanic Clouds, the Andromeda Galaxy and the Triangulum Galaxy, it is the brightest galaxy we can see. If we could perceive radio emission, then this galaxy would be visible to us in the form of two huge formations - jets emanating from its center.

The central region of the Centaurus A galaxy is surrounded by a mixture of young blue star clusters, giant clouds of gas and impressive dark dust lanes. These photographs were taken in natural color in X-ray and radio wavelengths by the Hubble Space Telescope. Infrared images from the Hubble Telescope made it possible to see disks of matter at the center of this galaxy, which, moving along spiral trajectories, fall into the black hole. Centaurus A appears to be the product of a collision between two galaxies, the matter of which is intensively “swallowed” by a black hole. Falling onto this hole, before “disappearing” into it, the matter emits huge jets of X-ray quanta. Astronomers believe that it is these central black holes that serve as sources of hard radiation. A powerful jet, ejected from the active nucleus of the galaxy upward and slightly to the left, stretched for about 13 thousand light years. The shorter burst exits the core in the opposite direction. The active galaxy Centaurus A likely arose from a merger with a less active spiral galaxy about 100 million years ago.

Lenticular galaxy 509px-Ngc5866. It is visible to us edge-on. Photo from the site: http://ru.wikipedia.org/wiki/

Astrophysicists say that “exotic” black holes by modern standards exist in almost all galaxies, but for some reason there is a “tense” with “ordinary” black holes in astrophysics. Low-mass black holes are thought to form when massive stars reach the end of their evolution and eject most of their material into the surrounding space in a supernova explosion. And the dense and compact cooling core that remains after them gradually turns into a black hole. Researchers also suggest that there are several million such low-mass black holes in our Universe. In almost every galaxy you can find such small black holes, and sometimes even several at the same time. However, they are difficult to detect, since they do not emit any light, no electromagnetic vibrations, or particle flows. This is why most black holes still remain undiscovered. However, in recent years, astronomers have made quite a lot of progress in this area. With the help of special scientific instruments and special techniques, they are able to detect more and more black holes in our Galaxy (so far, mainly in double star systems). To detect an ordinary black hole in the Centaurus A galaxy, astronomers used the X-ray range of the orbiting Chandra Telescope. The photo on the left shows a galaxy consisting of tenuous gas, the density of which increases towards its center. But this galaxy, which we see in profile, has a thin disk that consists of dark, opaque matter. Most likely, this disk consists of fragments ejected by the rapidly rotating superdense core (black hole) of the galaxy. These fragments were unable to form hydrogen atmospheres and become stars, and therefore are visible as dark bodies. It would be nice to look at this galaxy from the front.

Conclusion

In conclusion, we should summarize all of the above in the form of some general conclusion that expresses the essence of my hypothesis about the structure and dynamics of galaxies. At the beginning, we postulate that the Universe is eternal and infinite, that its matter can be found not only in the form of luminous or light matter that is familiar to us, consisting of quanta, elementary particles, atoms, molecules, clouds of gas and dust, asteroids, planets and stars, but and in a superdense state, which was not very aptly called black holes.

Black holes are not points in space where matter disappears; they are dark, non-luminous, spherical bodies that do not reflect the light falling on them. These bodies must rotate very quickly, and the more massive they are, the faster they rotate, flattening at the poles. The force of gravity on the surface of these black “tops” is such that the substance that falls on them loses its structure and is compressed to the density of the nucleus of an atom, and maybe even more. In all likelihood, the kinetic and thermal energy of the matter falling onto such a body is converted into the rotational energy of this superdense body, called a black hole. When the rotational energy reaches a certain limit, the gravity of the black hole is no longer able to hold the matter, and it begins to break away at the equator and, like a cannonball fired from a monstrous sling, flies away from the black hole. Such kernels ( Let's call them "fragmentaries"

At the center of spiral galaxies there are superdense objects that eject clumps of superdense matter - fragments. Ejected from the core of the galaxy (more precisely, from black holes in the core), clumps of superdense matter in their own gravitational field take the form of balls. But these bodies’ own gravity is not enough to keep matter in the same state of density as it was in a black hole. The matter in these bodies decompresses, causing their volume to increase, and from the protons and neutrons of the superdense clump, as it decompresses, heavy nuclei of chemical elements may be formed. Further decompression of the substance leads to the formation of electronic shells around the nuclei of atoms and they become atoms of heavy metals.

At this stage of evolution cosmic superdense bodies (fragmentaries) form their outer shells of gas and dust, capturing them from the galactic clouds through which they fly and into which they plunge, having been ejected from the core of the galaxy - from the black hole located at its center. Massive fragments form powerful atmospheres of hydrogen around themselves and subsequently become stars when thermonuclear reactions of fusion of helium nuclei from hydrogen nuclei begin in their depths. Some particularly massive fragments, moving from the center of the galaxy to its periphery, remain small black holes - black holes of the second order. They also collect hydrogen and dust from galactic clouds, but their gravity is so great that this gas and dust, falling onto these secondary black holes, turn into superdense matter and optically seem to “disappear in these holes.” Fragments smaller than secondary black holes decompress slightly and become the nuclei of future neutron stars, still others decompress more and become the cores of ordinary yellow stars, and still others, with a smaller initial mass and, therefore, less gravity, cannot hold very large atmospheres, they become not stars, but by planets. As we will see later, the cores of all planets and large spherical satellites of planets are heavy, metallic - iron, as planetary scientists say.

Thus, according to my hypothesis, stars and planets actually captured clouds of gas and dust from the arms of galaxies with their gravity, but these clouds themselves did not turn into stars, or into planets and their satellites. The initial source of gravity, organizing the gas and dust of the Cosmos into stars and planets, is super-dense matter ejected from black holes in the centers of galaxies - fragmentaries. The initial mass of these clumps of superdense matter, by its quantity, carries information about whether the forming cosmic body will be a second-order black hole, a neutron star, a yellow star or a planet. Moving in the galaxy, cosmic bodies gravitationally interact with each other and form gravitational systems: double and triple stars, planetary systems around stars, planetary systems from the central massive planet and its satellites.

In any case, in the cores of all spherical space objects there is or was at the initial moment of their existence superdense matter, which created the gravitational field. Cosmic bodies that are formed not from superdense, but from ordinary matter, have an irregular (non-spherical) shape, as a result of the complete or partial destruction of planets and their satellites. It is impossible to obtain superdense matter in laboratory conditions, so we can only guess about its properties by comparing cosmic bodies of different masses and different shapes “floating” in the space of galaxies.

There is a significant difference between this chaotic inflation scenario and the old hypothesis of the creation of the entire Universe at some zero point in time ( Big Bang) in the form of practically homogeneous matter heated to infinitely high temperatures in the form of the most elementary particles and quanta of the vacuum-ether. In the new model, the condition of initial homogeneity and thermodynamic equilibrium is no longer required. Each part of the Universe can have its own singular beginning (Borde et al, 2001). However, this does not mean that the entire Universe as a whole arose simultaneously from one singularity. Different parts of the universe could arise at different points in time and then grow. This means that we can no longer say that the entire universe was born at some point in time t=0, before which it did not exist.

The matter of the Universe can take different forms: 1 – matter of different densities, 2 – radiation, 3 – vacuum ether and 4 – singularity (superdense matter). The density of matter varies (in g/cubic cm): neutron stars 1014, white dwarfs 106, sun 1.4, red supergiants 5/100,000,000, galaxies and Metagalaxies as a whole have densities many orders of magnitude less than red ones supergiants (http://www.astronet.ru/db/msg/1202878). Some of the matter of the Metagalaxy is in the form of radiation and elementary particles; the density of this “radiant” matter is less than 1/1000 of the density of matter in the Metagalaxy. But a significant part of matter is in a state of singularity, i.e. black holes.

When writing this page, information from the following sites was also used:

1. Wikipedia. Access address: http://ru.wikipedia.org/wiki/

2. Astronet website. Access address: http://www.astronet.ru/db/msg/1225526

3. Silchenko O.K. Evolution of the central regions of galaxies. Access address: http://lib.tr200.net/v.php?id=94040&sp=1&fs=18; http://ziv.telescopes.ru

4. http://lib.tr200.net/v.php?id=94040&sp=1&fs=18

5. http://www.infuture.ru/article/5983

The concept " galaxy" in modern language means huge star systems. It comes from the Greek word “milk, milky” and was put into use to designate our star system, which represents a light stripe with a milky tint stretching across the entire sky and is therefore called the “Milky Way”. The number of stars in it is several hundred billion, i.e. about a trillion (10 12). It has the shape of a disk with a thickening in the center.

The diameter of the galaxy's disk is 10 21 m. The arms of the Galaxy have a spiral shape, that is, they diverge in spirals from the core. In one of the arms, at a distance of about 3 × 10 20 m from the core, there is the Sun, located near the plane of symmetry. The most numerous stars in our galaxy are dwarfs (their mass is about 10 times less than the mass of the Sun). In addition to single stars and their satellites (planets), there are double and multiple stars and entire star clusters (the Pleiades). More than 1000 of them have already been discovered. Globular clusters contain red and yellow stars - giants and supergiants. One of the objects in the Galaxy are nebulae, consisting mainly of gas and dust. Interstellar space is filled with fields and tenuous interstellar gas. The galaxy rotates around the center, and the angular and linear velocities change with increasing distance from the center. The linear speed of the Sun around the center of the Galaxy is 250 km/s. The Sun completes its orbit in approximately 290 million years (2×10 8 years).

At the beginning of the twentieth century, it was proven that there are others besides our Galaxy. Galaxies differ sharply in size, number of stars included in them, luminosity, and appearance. They are designated by numbers under which they are listed in catalogues.

Based on their appearance, galaxies are conventionally divided into three types: elliptical, spiral, and irregular.

Almost a quarter of all studied galaxies are elliptical. These are the simplest galaxies in structure.

Spiral galaxies are the most numerous type. It includes the Andromeda nebula (one of the closest galaxies to us), approximately 2.5 million light years away from us.

Irregular galaxies do not have central nuclei; no patterns have yet been discovered in their structure. These are the Large and Small Magellanic Clouds, which are satellites of our Galaxy.

Galaxies, as it turns out, form groups (tens of galaxies) and clusters consisting of hundreds and thousands of galaxies. Discoveries of the late 70s of the twentieth century showed that galaxies in superclusters are distributed unevenly: they are concentrated near the boundaries of cells, i.e. the Universe has a cellular (mesh, porous) structure. On small scales, matter in the Universe is distributed unevenly. On large scales it is homogeneous and isotropic. The metagalaxy is nonstationary. Let us note some features of the expansion of the metagalaxy:

1. Expansion manifests itself only at the level of clusters and superclusters of galaxies. The galaxies themselves are not expanding.

2. There is no center from which expansion occurs.

Bound by the forces of gravitational interaction. The number of stars and sizes of galaxies may vary. Typically, galaxies contain from several million to several trillion (1,000,000,000,000) stars. In addition to ordinary stars and the interstellar medium, galaxies also contain various nebulae. The sizes of galaxies range from several thousand to several hundred thousand light years. And the distance between galaxies reaches millions of light years.

About 90% of the mass of galaxies comes from dark matter and energy. The nature of these invisible components has not yet been studied. There is evidence that many galaxies have supermassive galaxies at their centers. The space between galaxies contains virtually no matter and has an average density of less than one atom per cubic meter. Presumably, there are about 100 billion galaxies in the visible part of the universe.

According to the classification proposed by astronomer Edwin Hubble in 1925, there are several types of galaxies:

• elliptical(E),
• lenticular(S0),
• regular spiral(S),
• crossed spiral(SB),
• incorrect (Ir).

Elliptical galaxies - a class of galaxies with a clearly defined spherical structure and decreasing brightness towards the edges. They rotate relatively slowly; noticeable rotation is observed only in galaxies with significant compression. In such galaxies there is no dust matter, which in those galaxies in which it is present is visible as dark stripes against a continuous background of the stars of the galaxy. Therefore, externally, elliptical galaxies differ from each other mainly in one feature - greater or lesser compression.

The share of elliptical galaxies in the total number of galaxies in the observable part of the universe is about 25%.

Spiral The galaxies are so named because they have bright arms of stellar origin within the disk that extend almost logarithmically from the bulge (the nearly spherical bulge at the center of the galaxy). Spiral galaxies have a central cluster and several spiral arms, or arms, that are bluish in color because they contain many young giant stars. These stars excite the glow of diffuse gas nebulae scattered along with dust clouds along the spiral arms. The disk of a spiral galaxy is usually surrounded by a large spheroidal halo (a ring of light around an object; an optical phenomenon) consisting of old second-generation stars. All spiral galaxies rotate at significant speeds, so stars, dust and gases are concentrated in a narrow disk. The abundance of gas and dust clouds and the presence of bright blue giants indicate active star formation processes occurring in the spiral arms of these galaxies.

Many spiral galaxies have a bar at the center, from the ends of which spiral arms extend. Our Galaxy is also a barred spiral galaxy.

Lenticular galaxies are an intermediate type between spiral and elliptical. They have a bulge, halo and disk, but no spiral arms. There are approximately 20% of them among all star systems. In these galaxies, the bright main body, the lens, is surrounded by a faint halo. Sometimes the lens has a ring around it.

Incorrect galaxies are galaxies that exhibit neither spiral nor elliptical structure. Most often, such galaxies have a chaotic shape without a pronounced core and spiral branches. As a percentage, they make up one quarter of all galaxies. Most irregular galaxies were spiral or elliptical in the past, but were deformed by gravitational forces.

Evolution of galaxies

The formation of galaxies is considered a natural stage of evolution, occurring under the influence of gravitational forces. As scientists suggest, about 14 billion years ago there was a big explosion, after which the Universe was the same everywhere. Then particles of dust and gas began to group, unite, collide, and thus clumps appeared, which later turned into galaxies. The variety of galaxy shapes is associated with the variety of initial conditions for the formation of galaxies. The accumulation of hydrogen gas within such clumps became the first stars.

From the moment of its birth, the galaxy begins to shrink. The contraction of the galaxy lasts about 3 billion years. During this time, the gas cloud transforms into a star system. Stars are formed by the gravitational compression of clouds of gas. When the center of the compressed cloud reaches densities and temperatures sufficient for thermonuclear reactions to occur effectively, a star is born. In the depths of massive stars, thermonuclear fusion of chemical elements heavier than helium occurs. These elements enter the primary hydrogen-helium environment during stellar explosions or during the quiet outflow of matter with stars. Elements heavier than iron are formed during enormous supernova explosions. Thus, first generation stars enrich the primary gas with chemical elements heavier than helium. These stars are the oldest and consist of hydrogen, helium and very small amounts of heavy elements. IN second generation stars the admixture of heavy elements is more noticeable, since they are formed from the primary gas already enriched with heavy elements.

The process of star birth occurs with the ongoing compression of the galaxy, so the formation of stars occurs closer and closer to the center of the system, and the closer to the center, the more heavy elements there should be in the stars. This conclusion agrees well with data on the abundance of chemical elements in stars in the halo of our Galaxy and elliptical galaxies. In a rotating galaxy, the stars of the future halo form at an earlier stage of contraction, when the rotation has not yet affected the overall shape of the galaxy. Evidence of this era in our Galaxy are globular star clusters.

When the compression of the protogalaxy stops, the kinetic energy of the resulting disk stars is equal to the energy of the collective gravitational interaction. At this time, conditions are created for the formation of a spiral structure, and the birth of stars occurs in the spiral branches, in which the gas is quite dense. This third generation stars. Ours is one of them.

The reserves of interstellar gas are gradually depleted, and the birth of stars becomes less intense. In a few billion years, when all gas reserves are exhausted, the spiral galaxy will turn into a lenticular galaxy, consisting of faint red stars. Elliptical galaxies are already at this stage: all the gas in them was consumed 10-15 billion years ago.

The age of galaxies is approximately the age of the Universe. One of the secrets of astronomy remains the question of what the nuclei of galaxies are. A very important discovery was that some galactic nuclei are active. This discovery was unexpected. Previously, it was believed that the galactic core was nothing more than a cluster of hundreds of millions of stars. It turned out that both the optical and radio emission of some galactic nuclei can change over several months. This means that within a short time, a huge amount of energy is released from the nuclei, hundreds of times greater than that released during a supernova explosion. Such nuclei are called “active”, and the processes occurring in them are called “activity”.

In 1963, objects of a new type were discovered located beyond the boundaries of our galaxy. These objects have a star-shaped appearance. Over time, they found out that their luminosity is many tens of times greater than the luminosity of galaxies! The most amazing thing is that their brightness changes. The power of their radiation is thousands of times greater than the power of active nuclei. These objects were named . It is now believed that the nuclei of some galaxies are quasars.

Galaxies– giant gravitationally bound systems of stars and star clusters, interstellar gas and dust, and dark matter. In space, galaxies are distributed unevenly: in one area you can detect a whole group of nearby galaxies, or you may not detect a single galaxy, even the smallest one. The exact number of galaxies in the observable universe is unknown, but it is likely to be on the order of one hundred billion.

The first condition The appearance of galaxies in the Universe was the appearance of random clusters and concentrations of matter in a homogeneous Universe. For the first time such an idea was expressed by I. Newton, who argued that if matter were uniformly scattered throughout infinite space, it would never have gathered into a single mass.

Second condition the appearance of galaxies - the presence of small disturbances, fluctuations of matter leading to a deviation from the homogeneity and isotropy of space. It was precisely the fluctuations that became the “seeds” that led to the appearance of larger compactions of matter. These processes can be represented by analogy with the processes of cloud formation in the Earth's atmosphere.

GENERAL CHARACTERISTICS OF GALAXIES(SIZE, LUMINITY, MASS, COMPOSITION)

Size. The concept of size is not strictly defined, because... galaxies do not have sharp boundaries; their brightness gradually decreases with distance from the center outward. The apparent size of galaxies depends on the telescope's ability to highlight their low-brightness outer regions against the glow of the night sky, which is never completely black. The peripheral parts of galaxies “drown” in its weak light. To objectively estimate the size of galaxies, a certain level of surface brightness, or, as they say, a certain isophote (the so-called line along which the surface brightness has a constant value) is conventionally taken as their boundary.

Luminosity of galaxies(i.e., the total radiation power) varies within even greater limits than their size - from several million solar luminosities (Lc) for the smallest galaxies to several hundred billion Lc for giant galaxies. This value roughly corresponds to the total number of stars in the galaxy, or its total mass.

Galaxy masses, as well as their luminosities, can also differ by several orders of magnitude - from a million solar masses to a thousand billion solar masses in some elliptical galaxies.

Composition and structure. The components of the Galaxy are stars, rarefied gas, dust (this is the interstellar medium) and cosmic rays. Galaxies are, first of all, star systems. Spatially, the stars form two main structural components of the galaxy, as if nested one inside the other: rapidly rotating star disk , And slowly rotating spherical (or spheroidal) component . The inner, brightest part of the spherodal component is called bulge (from the English bulge - swelling), and the outer part of low brightness - star halo . At the center of most galaxies there is a bright region called core. In the central part of massive galaxies, a small and rapidly rotating perinuclear disk which also consists of stars and gas. A large number of stars, closely interconnected by gravity, revolve around the galactic center as a satellite - this is - globular star cluster . In addition to globular star clusters. Unlike open star clusters, which are located in the galactic disk, globular clusters are located in the halo; they are much older, contain many more stars, have a symmetrical spherical shape and are characterized by an increase in the concentration of stars towards the center of the cluster. Observations of globular clusters indicate that they occur primarily in regions with efficient star formation, that is, where the interstellar medium is denser than normal star-forming regions.

Stars in open clusters are bound together by relatively weak gravitational forces, so as they orbit the galactic center, the clusters can be destroyed by passing close to other clusters or clouds of gas, in which case the stars that form them become part of the normal population of the galaxy. Open star clusters are found only in spiral and irregular galaxies, where active star formation processes occur.

In addition to stars with different masses, chemical compositions and ages, each galaxy contains a rarefied and slightly magnetized interstellar medium (gas and dust), penetrated by high-energy particles (cosmic rays). The relative mass attributable to the interstellar medium is also one of the most important observable characteristics of galaxies. The total mass of interstellar matter varies greatly from one galaxy to another and usually ranges from a few tenths of a percent to 50% of the total mass of stars (in rare cases, the gas can even predominate in mass over the stars). Content gas in a galaxy - this is a very important characteristic, on which the activity of processes occurring in galaxies and, above all, the process of star formation largely depends. Interstellar gas consists mainly of hydrogen and helium with a small admixture of heavier elements. These heavy elements are formed in stars and, together with the gas lost by the stars, end up in interstellar space.

The gaseous environment of interstellar space also contains a finely dispersed solid component - interstellar dust. She manifests herself in two ways. First, dust absorbs visible and ultraviolet light, causing an overall dimming and reddening of the galaxy. The most opaque (due to dust) areas of the galaxy are visible as dark areas against a light, bright background. There are especially many opaque regions near the plane of the stellar disk - this is where the cold interstellar medium is concentrated. Secondly, the dust itself radiates, releasing the accumulated light energy in the form of far infrared radiation. The total mass of the dust is relatively small: it is several hundred times less than the total mass of interstellar gas.

Galaxies are very diverse: among them one can distinguish spherical elliptical galaxies, disk spiral galaxies, barred galaxies, lenticular, dwarf, irregular, etc. The variety of observed shapes of galaxies has caused astronomers to want to combine similar objects and divide galaxies into series classes according to their appearance (morphology). The most commonly used morphological classification of galaxies is based on the scheme proposed by E. Hubble in 1925 and developed by him in 1936. Galaxies are divided into several main classes: elliptical (E), spiral (S), lenticular (S0) and irregular (Irr).

Elliptical E-galaxies They look like elliptical or oval spots, not too elongated, the brightness inside of which gradually decreases with distance from the center. There is usually no internal structure (there is no noticeable disk in them, although precise photometric measurements in some cases allow one to suspect its existence. Traces of dust or gas are also rarely found in them)

Spiral galaxies (S) is the most common type (about half of them). Typical representatives are our Galaxy and the Andromeda nebula. Unlike elliptical galaxies, they exhibit a structure in the form of characteristic spiral branches. Despite the variety of shapes, spiral galaxies have a similar structure. Three main components are observed in them: a stellar disk, a spheroidal component, a bright inner region called the bulge, and a flat component, which is several times smaller in thickness than the disk. The flat component includes interstellar gas, dust, young stars, and spiral arms. Our Galaxy has a similar structure.

Between types E and S there is a type lenticular galaxies (S0). Like S galaxies, they have a stellar disk and bulge, but they do not have spiral arms. It is believed that these are galaxies that were spiral in the distant past, but have now almost completely “lost” or used up interstellar gas, and with it the ability to form bright spiral branches. Any spiral galaxy, if stripped of gas and young stars, will be classified as lenticular.

Irregular Irr galaxies do not have an ordered structure, they do not have spiral branches, although they contain bright regions of various sizes (as a rule, these are regions of intense star formation). The bulge in these galaxies is very small or completely absent. These galaxies tend to be high in interstellar gas and young stars.

Some galaxies have an unusually bright nucleus. Galaxies with active nuclei are usually divided into several types. There are Seyfert galaxies, radio galaxies, quasars C Heifert galaxies are named in honor of the American astronomer Carl Seyfert, who first noticed them in 1943. In some cases, the nuclei of Seyfert galaxies are 100 billion times brighter than the Sun. S.g. - these are, as a rule, spiral galaxies. The most likely hypothesis to explain the activity of the nuclei assumes the presence of a black hole (with a mass of tens or hundreds of millions of solar masses) in the center of the galaxy.

The most unusual of all are objects called quasars. The English term quasar literally means “star-like radio source”) - a powerful and distant active galactic nucleus. They emit from an area with a diameter of less than 1 light. years, the same amount of energy as would be emitted by hundreds of normal galaxies. Despite their unusual nature, quasars are not visually impressive, so they were not noticed until after 1963.

Today, the most common point of view is that a quasar is a supermassive black hole that sucks in surrounding matter. As charged particles approach a black hole, they accelerate and collide, resulting in intense light emission. According to another point of view, quasars are the first young galaxies, and we are simply observing the process of their birth. However, there is also an intermediate, although it would be more accurate to say a “united” version of the hypothesis, according to which a quasar is a black hole that absorbs the matter of a forming galaxy.

A radio galaxy is a type of galaxy that has much greater radio emission compared to other galaxies. Radiation sources of radio galaxies usually consist of several components (core, halo, radio emissions). Radio galaxies usually have the shape of ellipses and are gigantic in size.

Several percent of the observed galaxies do not fit into the described classification scheme; they are called Peculiar. Typically these are galaxies whose shape is distorted by strong interactions with neighboring galaxies (such galaxies are called interacting.

There is no clear definition for this term, and the assignment of galaxies to this type may be disputed. Sometimes the classification of a galaxy as a peculiar type was disputed. So, for example, B.A. Vorontsov-Velyaminov believed that interacting galaxies are not peculiar, since visible changes in their shape are caused by disturbances of close neighbors. However, among interacting systems there are objects of such bizarre shapes that it is difficult not to call them peculiar.

A classic example of a peculiar galaxy is the radio galaxy Centaurus A (NGC 5128). In a separate group are allocated dwarf galaxies

Evolution of galaxies

- small in size, the luminosity of which is thousands of times less than that of galaxies such as ours or the Andromeda nebula. They are the most numerous class of galaxies, but their low luminosity makes them difficult to detect at great distances. Among them there are also elliptical dE, spiral dS (very rare), and irregular (dIrr). The letter d (from the English dwarf - dwarf) denotes membership in dwarf systems.

The observed diversity of galaxies is a consequence of the different conditions in which they arose. Analysis of the spectra and stellar composition of galaxies showed that the vast majority of them are very old and were formed 10-15 billion years ago. According to modern concepts, the formation of galaxies began in the early era of the expansion of the Universe, when the average density of matter in the Universe was hundreds of times greater than at present. Galaxies arose from hydrogen-helium gas clouds collapsing under the influence of their own gravity. At a certain stage of compression, intense star formation began in protogalaxies. Massive stars, rapidly evolving and exploding as supernovae, ejected gas enriched with various chemical elements resulting from the explosion into the surrounding space. The formation of a disk in galaxies is associated with(Energy dissipation is the transition of part of the energy of ordered processes (kinetic energy of a moving body, electric current energy, etc.) into the energy of disordered processes, ultimately into heat.) gas energy in a contracting protogalaxy. Possessing a certain torque, the gas, losing its mechanical energy, was compressed into a disk, which, as a result of the formation of stars from the gas, gradually became a stellar disk.

A major role in the evolution of galaxies was played by the absorption of smaller systems by large galaxies, which were destroyed by tidal forces and replenished the mass of the forming galaxies.

CLUSTERS AND SUPERCLUSTERS

The photographs of galaxies show that there are few truly lonely galaxies. About 95% of galaxies form groups of galaxies.. They are often dominated by one massive elliptical or spiral galaxy, which, due to tidal forces, destroys satellite galaxies over time and increases its mass, consuming them.

Cluster of galaxies are called associations of several hundred galaxies, which can contain both individual galaxies and groups of galaxies. Typically, when observed at this scale, several very bright supermassive elliptical galaxies can be identified. Such galaxies should directly influence the process of formation and formation of the cluster structure.

Supercluster- the largest type of galaxy association, includes thousands of galaxies. At the scale of superclusters, galaxies arrange themselves into bands and filaments surrounding vast, sparse voids. The shape of such clusters can vary from a chain, such as the Markarian chain, to walls, such as the great wall of Sloan.

Local group of galaxies. Milky way galaxy

The Local Group of galaxies is a collection of nearby galaxies, the distances to which do not exceed approximately 1 million pc (about 3 million light years). It consists of two large groups and dwarf galaxies scattered among them - about 30 members in total. One of the groups is dominated by our Galaxy with its nearby Magellanic Clouds in size, mass and light intensity. In another group, the main place is occupied by a spiral galaxy (Andromeda nebula), which is even more powerful. It is adjacent to a smaller spiral galaxy - M 33 in the Triangulum, two small elliptical galaxies and several dwarf galaxies. The galaxies included in the M. g. g., due to their proximity to us, are accessible to the most detailed study.

Members of the Local Group move relative to each other, but are connected by mutual gravity and therefore occupy a limited space of about 6 million light years for a long time and exist separately from other similar groups of galaxies. All members of the Local Group are believed to have a common origin and have been coevolving for about 13 billion years.

Our Galaxy - the Milky Way - has the shape of a disk with a bulge in the center - the core, from which spiral arms extend. Its thickness is 1.5 thousand light years, and its diameter is 100 thousand light years. The age of our Galaxy is about 15 billion years. It rotates in a rather complex way: a significant part of its galactic matter rotates differentially, like planets rotate around the Sun, without paying attention to the orbits in which other, fairly distant cosmic bodies move, and the speed of rotation of these bodies decreases with increasing their distance from the center. Another part of the disk of our Galaxy rotates solidly, like a music disk spinning on a record player. Our Sun is located in a region of the Galaxy in which the velocities of solid-state and differential rotation are equal. Such a place is called a corotation circle. It creates special, calm and stationary conditions for star formation processes.

Our Galaxy has two small satellite galaxies called the Magellanic Clouds. There are Large and Small Magellanic Clouds. These are rich areas for observation with instruments of all sizes and are visible to the naked eye in the Southern Hemisphere. The Magellanic Clouds were familiar to sailors in the southern hemisphere and were called the "Cape Clouds" in the 15th century. Ferdinand Magellan used them for navigation, as an alternative to the North Star, during his trip around the world in 1519-1521. When, after the death of Magellan, his ship returned to Europe, Antonio Pigafetta (Magellan's companion and official chronicler of the trip) proposed calling the Cape Clouds Magellan's Clouds as a kind of perpetuation of his memory

Both Clouds were previously considered irregular galaxies, but subsequently discovered structural features of barred spiral galaxies. They are located relatively close to each other and form a gravitationally bound (double) system. Both Magellanic Clouds are immersed in a common shell of neutral hydrogen. In addition, they are connected to each other by a hydrogen bridge

There are a lot of star clusters in the Magellanic Clouds. Scientists have recorded 1,100 open clusters in the Large Cloud and more than 100 in the Small Cloud. 35 globular clusters have been discovered in the Large Cloud, and 5 in the Small Cloud. Globular clusters have been discovered in the Magellanic Clouds, which are not found in our Galaxy. They contain many blue and white giants. That's why they are white. Ordinary globular clusters consist of red giants, so their color is yellow-orange.

1). A star as an object of study in astrophysics.

2). Classifications of stars.

3). The birth and evolution of stars.