INSTRUCTIONS AND PROPHECIES OF THE Blessed MOTHER ALIPIA GOLOSEEVSKY, Kyiv...
Peering into the night starry sky, we can see a wide band, completely strewn with stars: bright and barely noticeable, white and blue, reddish and green. The ancient Greeks called this cluster of stars galaxy, which means in Russian .
Milky Way in the night sky
If you look at this star system from somewhere else, from world space, you might notice that it resembles a flattened ball filled with 150 billion stars. The dimensions of our Galaxy are so large that it is difficult to imagine them. From one edge to the other, a light beam travels about 100,000 Earth years!
This is what our galaxy looks like
At the center of our Galaxy is the core, from which several huge spiral branches filled with stars depart. Our Sun is located at a distance of 30 thousand light years from the core of the Galaxy, in one of its spiral arms. That is, it is located on the outskirts of the Galaxy.
The position of the Sun in the Galaxy
The stars in the Galaxy, despite the apparent "density", are quite rare. For example, in the vicinity of the Sun, the average distance between the nearest stars is about 10 million times greater than their own diameters.
Thus, the stars in the universe are not scattered randomly. They are grouped into ordered systems in which they are connected to each other by the force of gravity (attraction). Such star systems are called galaxies. In addition to stars, galaxies also contain interstellar dust and gas.
There are other galaxies in the Universe. The closest to our star system are removed from us at a distance of about 150 thousand light years. In the sky of the Southern Hemisphere, they are visible as small hazy specks.
For the first time, these star clusters were described in detail by Magellan's companion Pigafetta during the famous world travel. They entered astronomy under the name of the Magellanic Clouds - Large and Small.
One of the closest galaxies to us Andromeda's nebula. It is one of the largest star systems in our region of the universe. It can be observed even with ordinary binoculars, and in good weather - with the naked eye.
Galaxies have a wide variety of shapes and structures. There are spherical and elliptical, disk-shaped, spiral, like ours, and irregularly shaped galaxies.
In the part of the universe accessible modern means astronomical research, there are billions of galaxies. Astronomers have named their collection Metagalaxy.
Galaxy
One of the greatest mysteries of the universe is that the infinite trillions of stars are not evenly scattered throughout outer space. No, stars cluster into galaxies, just like people gather in cities, leaving the spaces between them uninhabited.
The name of our galaxy is the Milky Way. This is a huge rotating flat disk, consisting of gas, dust and about 200 billion stars. The distance between neighboring stars in a galaxy is trillions of kilometers of empty space. Our Sun, one of the many stars that inhabit the galaxy, is located on its periphery.
When we look at the night sky, we look through the stars, as through raindrops stuck to a window pane. All the individual stars that we see in the sky belong to the Milky Way. Our Galaxy has a spiral shape. From above, it looks like a whirlwind of stars. Stars revolve around the center of the galaxy, just as planets revolve around stars.
It takes the Sun about 200 million years to make one revolution in this stellar carousel, and it moves at a speed of no less than 940,000 kilometers per hour. From the side, the galaxy looks like a disk with an elevation in the center. The bright white streak that crosses the sky on a clear night is part of this disk.
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Interesting facts about space
Other galaxies
This is how we see our galaxy. If we could get beyond it, we would be able to see the Universe in all its pristine beauty: a huge impenetrable - black space, across which brightly lit galaxies are scattered, like illuminated islands in the night sea. The Milky Way itself is a huge cosmic entity, but it is only one of 100 billion galaxies in observable space.
Although each galaxy is a cluster of millions of suns, they are located so far from us that they are perceived as rather dim nebulae. With a small telescope, you can see dozens of galaxies. Well, if you use the most modern powerful telescope, you can not only look at many galaxies, but also make out individual stars in some galaxies.
On a very clear night, it is sometimes possible to see the Andromeda Galaxy, the nearest neighbor of the Milky Way. Moreover, no optical device is needed for this. Just like the Milky Way, the Andromeda Nebula is a spiral. More than half of all galaxies are spiral. Such galaxies, like a village spinning wheel, contain new, old, and middle-aged stars.
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Galaxies of a different shape
There are elliptical galaxies. These are huge rounded balls, consisting of billions of stars. Some of these galaxies are almost perfectly round, while others are slightly flattened. In elliptical galaxies, the stars rotate very closely around the center, resembling a swarm of bees. Most often, elliptical galaxies are composed of old stars, many of which are red giants.
Therefore, elliptical galaxies almost always glow red or orange. There are galaxies and other forms. There are galaxies that resemble a biconvex lens in shape, or spiral galaxies without a thickening in the center. There are galaxies that don't have any shape at all. Such galaxies are called irregular.
Incidents with galaxies
Although from the side of the galaxy they look like peaceful and serene clusters of stars, their appearance can be very deceiving. These worlds are the scene of extreme natural shocks, the galactic equivalent of earthquakes and volcanic eruptions. Here modern example. From the center of the galaxy M87 there was a monstrous ejection of blue - white hot gas. Released into space great amount energy. The fiery tongue of ejected gas is about 5,000 light-years long. Scientists think the black hole at the center of the galaxy, engulfing cosmic dust and entire stars, is the source of this eerily majestic performance.
We have a magnificent observatory in the city. And I loved to disappear there in my school years. The workers were loyal to me and fed my curiosity, shared the nuances of work and interesting astronomical facts. I remember that time with great fondness. What is a galaxy? It's one of the fundamental concepts. I remember how they took me around the observatory museum and told me about it. What shortly after the Big Bang galaxies began to form as stars were born and gravitationally attracted to each other in sheets of gas caused by small fluctuations in the density of matter in the young universe. Then the stars began to form protogalaxies. It was very hard to imagine. But it felt like something unthinkable, grandiose. In fact, now I understand what the galaxy is collection of stars and planets, a huge amount of gas and dust that are held together by gravity. And all the heavenly bodies revolve around the central object. Just dry facts. And then it was practically magic. There, in the observatory, there were huge models of various types of galaxies. It turns out that most of the bright galaxies nearby are spiral. They differ in shape and size, interact with each other, sometimes crash into each other and merge, sometimes tearing each other apart. In general, all galaxies are divided into four main types: Spiral galaxy emerges when stars inside a protogalaxy are born at different intervals. The gas between developing stars is collapsing, and as a result, gravitational differences govern the stars, dust, and gas of the protogalaxy. This movement causes everything to rotate, and differences in gravity lead to the appearance of spiral arms. When I look at the sky, I constantly mentally fly away to the stars and see in my imagination all this splendor. Stars gather into galaxies. Galaxies - into groups of galaxies, and these groups - into clusters. Helpful1 Not very good Comments0 Many kids love Milky Way bars. And my grandson is no exception. Knowing the basics of the English language, he understands that milky means milky, and way means the way, the road. But recently he learned that the creators meant by this name not a trip along the roads with milk chocolate, but the name of our Galaxy "Milky Way". And then a hail of questions rained down: I will try to answer these questions. I think that the answers may be useful to you in communicating with your children and grandchildren. The beauty of the night sky, the celestial objects and phenomena themselves have attracted the attention of people since time immemorial. But astronomical knowledge, which has taken shape in science, has come down to us from scientists Ancient Greece(Hellas). So, for example, the picture of the world Ptolemy dominated Europe for 14 centuries. But among the ancient Greeks themselves, ideas about the world around were intertwined with their religious ideas and myths. Name "Milky Way" comes from Hellenic legends. When the boy was born who was to become a mighty hero Hercules he was placed on the bed of the sleeping supreme goddess Hera so that he drank her breast milk and became immortal. But Hera woke up and pushed the mortal baby away, while her milk splashed across the sky, forming a whitish sparkling strip across the entire celestial sphere. So, according to the ideas of the Hellenes, "Milky (Milky) Way". "Galaxy", translated from ancient Greek, means "Milky Way". Of course, in our time, no one would even think of believing in such an explanation for the appearance of this amazing object in our sky. So what is Galaxy in fact? We understand that life on Earth can only exist thanks to the radiation of light and heat from a huge cosmic object called sun. This fireball could contain 1,300,000 Earth-sized planets. But it looks like the size of a soccer ball, because it is very far from us. It turns out that all the stars in our sky are nothing but the same luminaries, somewhat different in temperature, size and age. It's just that they are all removed from us at colossal cosmic distances, which is why they look like burning sparks. Stars in the universe are not distributed randomly. They are collected by the forces of attraction into stellar associations, which, due to rotation, take the form of a disk thickened in the center. They are called galaxies. The star formation to which our Sun belongs is called "Milky Way". We see it from the side, which is why it sparkles with a whitish stripe across the sky. Almost all objects observed in the starry sky also enter our galaxy. Ferdinand Magellan used whitish nebulae in the 15th century for navigation in the Southern Hemisphere, later named Magellanic Clouds. Another such luminous little cloud ( Andromeda's nebula) back in the 10th century, a Persian astronomer observed As-Sufi. Only in the 19th century, scientists armed with sophisticated optical equipment were able to prove that these objects are located outside of our galaxies and, just like "Milky Way", are huge star clusters. These are the others closest to us, Galaxies. And there are billions of them. Helpful1 Not very good Comments0 When I was in the 7th (!) grade, I argued with my desk mate about which is bigger: the galaxy or the universe. Now I am very ashamed of this argument. Thankfully, I've learned a lot more about the universe since then. The galaxy is not a measure of the division of the universe, as some people (mostly children) mistakenly believe. It's just a collection of stars, gas, dust, dark matter, planets, held together by a gravitational field and moving relative to the center of mass. This is how not only planets and satellites move, but even the galaxy itself. Our galaxy is no exception, and we are now moving at great speed towards the center of the universe. Some of the galaxies can be seen from our planet even without the aid of a telescope. Unfortunately, there are only 4 of them: It will be interesting to know that our galaxy is spiral, that is, it has arms, our solar system is located on the inner edge of one of them (Orion's arm), due to this location in the galaxy, we cannot see part of the arm through a telescope, for example . In fact, there are very few lonely galaxies in the universe. About 96% are galactic associations. Very often in such clusters of galaxies there is one that is much larger than the others (dominant), and it is she who attracts the rest with her gravitational field. Over time, the largest galaxies absorb smaller ones, increasing their size. Our galaxy is not alone either, it belongs to the local group of galaxies and dominates it along with Andromeda. The exact number of galaxies in our group is unknown, it is assumed that there are about 43 of them. The dimensions of the universe itself are colossal, but it is also finite, there is absolutely nothing beyond 13.7 billion light years. But even the greatest minds of mankind find it difficult to answer the question of what this “nothing” is. Useful0 Not very Comments0 I've been interested in astronomy for quite a long time, and I've studied everything! Films, books, pictures, articles, now it can be easily found, and I will try to answer your question here with the help of my knowledge. :) Space is fraught with many dangers and mysteries, and there is hardly a better place for us than the Earth. But let's take a look, shall we? Everyone can well imagine our home planet, if you go higher into space, then there will be our solar system. It includes: We are leaving our solar system, but how many are around?! Can't count, billions planets, stars unimaginable in size clouds of gas, dust, energy... All this was formed due to the attraction to each other of this all by the forces gravity. All this (our galaxy) revolves around supermassive black hole. This object has not been studied at all, because according to modern concepts, a black hole is nothing does not radiate, but only "sucks" objects into itself, literally dissolving them. But do not be afraid, we are far from it. The picture shows white patches- places with a lower temperature, but not all are clogged with planets and stars, there are dark areas- lots are empty. Look at this photo: Lots of lights, but it's really millions of galaxies, in our time, astronomers can observe them, but there are boundaries. The level of development of technology does not allow us to look further, we can only observe where we can look. Galaxy (Late Greek Galaktikos - milky, milky, from Greek gala - milk)
the vast star system to which the Sun belongs, and therefore our entire planetary system, together with the Earth. G. consists of many stars of various types, as well as star clusters and associations, gas and dust nebulae, and individual atoms and particles scattered in interstellar space. Most of them occupy a lenticular volume with a diameter of about 30 and a thickness of about 4 kiloparsec.
(respectively, about 100 thousand and 12 thousand light years). A smaller part fills an almost spherical volume with a radius of about 15 kiloparsec (about 50 thousand light years). All components of G. are connected into a single dynamic system, rotating around the minor axis of symmetry. To an earthly observer who is inside the G., it appears in the form of the Milky Way (hence its name - "G.") and the whole multitude of individual stars visible in the sky. In this regard, G. is also called the system of the Milky Way. Unlike all other galaxies (See Galaxies) ,
the one to which the Sun belongs is sometimes called "our Galaxy" (the term is always written with a capital letter). Stars and interstellar gas and dust fill the volume of the galaxy unevenly: they are most concentrated near the plane perpendicular to the axis of rotation of the galaxy and which is its plane of symmetry (the so-called galactic plane). Near the line of intersection of this plane with the celestial sphere (the galactic equator (See Galactic equator))
and the Milky Way is visible, the middle line of which is almost a large circle, since the solar system is located not far from this plane. The Milky Way is a cluster of a huge number of stars merging into a wide whitish band; however, the stars projected nearby in the sky are far from each other in space at great distances, excluding their collisions, despite the fact that they move at high speeds (tens and hundreds km/s)
in different directions. The lowest density of the distribution of stars in space (spatial density) is observed in the direction of the planet's poles (its north pole is in the constellation Coma Berenices). The total number of stars in G. is estimated at 100 billion. Interstellar matter is also scattered in space unevenly, concentrating mainly near the galactic plane in the form of globules (See Globules) ,
individual clouds and nebulae (from 5 to 20-30 parsecs in diameter), their complexes or amorphous diffuse formations. Particularly powerful, relatively close to us, dark nebulae appear to the naked eye in the form of dark glades. irregular shapes against the background of the strip of the Milky Way; the scarcity of stars in them is the result of the absorption of light by these nonluminous dust clouds. Many interstellar clouds are illuminated by high-luminosity stars close to them and appear as bright nebulae, because they glow either by reflected light (if they consist of cosmic dust particles) or as a result of the excitation of atoms and their subsequent emission of energy (if the nebulae are gaseous). The total mass of galaxies, including all stars and interstellar matter, is estimated at 10 11 solar masses, i.e., about 10 44 G. As the results of detailed studies show, the structure of the galaxy is similar to the structure of a large galaxy in the constellation Andromeda, a galaxy in the constellation Coma Veronica, etc. However, being inside the galaxy, we cannot see its entire structure as a whole, which makes it difficult to study it. The stellar nature of the Milky Way was first discovered by G. Galileo in 1610, but a consistent study of the structure of the Milky Way began only at the end of the 18th century, when V. Herschel, using his "scoop method", calculated the number of stars visible in his telescope in various directions. Based on the results of these observations, he suggested that the observed stars form a giant oblate system. V. Ya. Struve discovered (1847) that the number of stars per unit volume increases with approach to the galactic plane, that interstellar space is not perfectly transparent, and the Sun is not located at the center of G. In 1859, M. A. Kovalsky pointed out a probable axial rotation of the entire gyratory system. The first more or less substantiated estimates of the dimensions of the horn were made by the German astronomer H. Zeliger and the Dutch astronomer J. Kaptein in the first quarter of the 20th century. Zeliger, admitting an uneven distribution of stars in space and their different luminosities, concluded that surfaces of the same stellar density are ellipsoids of revolution with a contraction of 1:5. However, due to the disregard for the distorting effect of interstellar absorption of stellar light, many of the first conclusions were erroneous; in particular, the dimensions of the city turned out to be exaggerated. When determining the position of the Sun (Earth) in the city, most researchers attributed it to the center of the city, main reason which was also ignoring the effect of light absorption. This view was also supported by the vitality of the geocentric and anthropocentric world view. In the 20s. 20th century The American astronomer H. Shapley finally proved the non-central position of the Sun in H., while determining the direction to the center of H. (in the constellation Sagittarius). In the mid 20s. 20th century G. Strömberg (USA), studying the laws of motion of the Sun relative to various groups of stars, discovered the so-called. the asymmetry of stellar movements, which provided factual material for substantiating many conclusions about the complexity of the structure G. Shved. the astronomer B. Lindblad (20s of the 20th century), studying the dynamics and structure of gyroscopes on the basis of an analysis of the velocities of stars, discovered the complexity of the structure of gyros and the fundamental difference in the spatial velocities of the stars inhabiting different parts of the gyrus, although they are all connected into a single system symmetrical with respect to the galactic plane. Dutch astronomer J. Oort in 1927 based statistical study The radial velocities and proper motions of stars proved the existence of gyratory rotation around its own minor axis. It turned out that the internal, closer to the center, parts of the G. rotate faster than the external ones. At the distance of the Sun from the center of G. (10 kiloparsec) this speed is about 250 km/s; the period of a complete revolution is about 180 million years. The proof of interstellar absorption of stellar light (1930, by the Soviet astronomer B. A. Vorontsov-Velyaminov and the American astronomer R. Trampler), and its quantitative estimates and accounting made it possible to refine the distances to individual galactic objects and the size of the galaxy, and laid the foundation for revealing the details of its structure. Numerous studies of the spatial distribution of stars various types(Soviet astronomer P. P. Parenago and others), proper motions of stars (early works by S. K. Kostinsky at the Pulkovo Observatory, American astronomer V. Bos, etc.), motions of the Sun in space, as well as motions of stellar streams ( Soviet astronomer V. G. Fesenkov, Dutch astronomer A. Blau, etc.), the study of the galactic gravitational field, etc., made it possible to discover, on the one hand, many common patterns, and on the other hand, a great variety in the kinematic, physical and structural characteristics of individual components G. In the 30s and subsequent years of the 20th century. Soviet astronomical observatories have made significant progress in the field of astronomical research. Important results have been obtained: in the field of the dynamics of stellar systems; in observations and compilation of numerous catalogs of the parameters of stars and other galactic objects; in the development of new views on the nature of the interstellar medium; in the development of new theories and methods that made it possible to carry out quantitative estimates of the parameters characterizing absorption in galactic space; in elucidating the connections between stars and interstellar matter. In selected regions of the Milky Way, according to the plan of G. A. Shain (USSR) and according to the comprehensive plan of P. P. Parenago, photometry and spectral classification of tens of thousands of stars were carried out. The discovery of stellar associations was of great importance for understanding the processes of development of galaxies. A major role in the study of G. was played by the successes Soviet science about variable stars. Comparison of their physical features and morphological characteristics with age and spatial parameters made it possible to solve a number of problems of the structure and nature of geography. Research by Soviet and American astronomers made the complex structure of geology obvious. It turned out that different, quite definite elements of their composition correspond to different parts of geology. In 1948, as a result of observations in infrared rays, Soviet researchers obtained for the first time an image of the G nucleus. 20th century showed that our G. has spiral arms. The study of astronomy, its structure, and development is primarily the subject of three branches of astronomy: stellar astronomy, astrometry, and astrophysics. All these sections have played a great role in refining and detailing our ideas about G. Of great importance for the study of G. was the development of radio astronomy, which received a lot of new information about G. Radio astronomical observations made it possible to discover a large number of sources of radiation in the radio range in interstellar space G., masses of neutral hydrogen, to study their movements, to find out common features internal structure G. By the beginning of the 70s. 20th century as a result of studies carried out in the USSR and abroad, the following idea of g. has developed. , The thickness of the layer located along the plane of the galactic equator, inside which the majority of stars and the bulk of the interstellar matter is located, is 400-500 parsec. The spatial density of stars in it is such that one star falls on a volume equal to a cube with an edge of 2 parsec. In the vicinity of the Sun, the density is somewhat less. It increases significantly as it approaches the center of G., which, when observed from the Earth, is visible in the constellation Sagittarius. Consequently, the distribution of stars is characterized by a concentration both toward the planetary plane and toward its center. The total mass of interstellar gas in G. is about 0.05 the mass of all stars, and its average density near the plane of the equator does not exceed 10 -25 or 10 -24 g/cm 3. Interstellar dust, consisting of solid particles, the radii of which are of the order of 10 -4 -10 -5 cm, in its mass is about 100 times less than the mass of gas. Due to its negligible mass, dust does not affect the dynamics of gravity, but nevertheless noticeably affects the visible structure of gravity, scattering the light of stars passing through its medium. The core of the galaxy, being immersed in relatively dense masses of interstellar matter, is little accessible to optical observations, but radio astronomical observations indicate the activity of the core, the presence in it of large masses of matter and energy sources. G. has a pronounced subsystem structure; There are three subsystems: flat, intermediate and spherical. The flat subsystem is characterized by the presence of young hot stars, variable stars such as long-period Cepheids, stellar associations, open star clusters, and gas and dust matter. All of them are concentrated near the galactic plane in the form of an equatorial disk (thickness is 1/20 of the galactic diameter). Average age The stellar population of the disk is about 3 billion years. The yellow and red dwarf and giant stars, which occupy a volume in the form of a strongly oblate ellipsoid, are less concentrated towards the galvanic plane. All subdwarfs, yellow and red giants, variable stars such as short-period Cepheids and globular star clusters form a spherical component (sometimes called a halo), filling a spherical volume (with an average diameter exceeding 30 thousand km). parsec, i.e., 100 thousand light years) with a sharp drop in density in the direction from the central regions to the periphery. Its age is more than 5 billion years. Objects of different components differ from each other also in the speed of movement, and chemical composition. The stars of the flat component have high velocities of motion relative to the center of the galaxy, and they are richer in metals. This indicates that the stars different types belonging to different subsystems were formed under different initial conditions and in various fields space occupied by galactic matter. The entire galactic system is immersed in a vast gaseous mass, which is sometimes called the galactic corona (See Galactic corona). Spiral branches propagate from the central region of the galaxy along the galactic plane, which, going around the nucleus and branching, gradually expand, losing brightness. A spiral structure that turned out to be very characteristic property galaxies at some stage of their evolution, G. is similar to many other stellar systems of the same type as it, which have the same stellar composition. Apparently, gravitational forces and magnetohydrodynamic phenomena play a role in the development of the spiral structure, while it is also influenced by the features of rotation G. Star formation occurs along the spiral branches and they are inhabited by the youngest galactic objects. Questions of the evolution of geometry as a whole or of its individual constituent elements are of great ideological significance. For a long time, the view that all stars and other objects formed simultaneously dominated. Such a view was associated with the recognition of the simultaneous origin of all galaxies at one point in the Universe and their subsequent “scattering” in different directions from it. However, detailed studies based on numerous observations led to the conclusion (by the Soviet astronomer V. A. Ambartsumyan) that the process of star formation continues in the present epoch. The problem of the origin and development of stars in galaxies is a fundamental problem. There are two main but opposite points of view on the formation of stars. According to the first of these, stars are formed from gaseous matter, which is scattered in significant amounts in the galaxy and observed by optical and radio astronomical methods. gas substance where its mass and density reach a sufficiently large value, it contracts and condenses under the influence of its own attraction, forming a cold ball. In the process of further compression, the temperature inside it, however, rises to several million degrees; this is sufficient for the occurrence thermonuclear reactions, which, together with the processes of radiation, determine the further evolution of this ball-star. According to the second point of view, stars are formed from some superdense matter. Superdense matter of this kind has not yet been discovered and its properties are unknown, but the fact that in the observable Universe the processes of outflow of masses from stars, fission and decay of systems are observed in many cases, while the processes of formation of stars from interstellar matter are not observed, speaks in favor of the second point vision. It is assumed that the gas as a whole developed in the process of condensation of a primary gas cloud rich in hydrogen; the stars formed in this process are observed in our epoch as stars of the spherical component, poor in metals and having the greatest age. The primary gas cloud, continuing to shrink under the influence of gravitational forces, was enriched in metals due to the ejection of matter from the interiors of previously formed stars, in which intranuclear reactions had been going on for many hundreds of millions of years and hydrogen was turning into heavier elements. For this reason, the later "generation" of stars that formed the G disk turned out to be richer in metals. This concept explains the observed distribution of stellar velocities and the stratification of the latter into subsystems. However, there are many inconsistencies in this picture. The idea developed by a number of Soviet astronomers about the role of powerful explosive repulsive forces hidden in the interior of galaxies in the evolution of galaxies can shed new light on the problem of the development of G. Cm. ill.
Lit.: Parenago P. P., Course of stellar astronomy, 3rd ed., M., 1954; Bok B. J. and Bok P. F., Milky Way, trans. from English, M., 1959; Course of astrophysics and stellar astronomy, vol. 2, M., 1962; Bakulin P. I., Kononovich E. V., Moroz V. I., Course of General Astronomy, M., 1966. E. K. Kharadze. Great Soviet Encyclopedia. - M.: Soviet Encyclopedia.
1969-1978
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GALAXY, a huge collection of stars, dust and gas. An example is our own Galaxy. According to Edwin Hubble's 1925 classification, there are three main types of galaxies. Elliptical galaxies (E) are round or ... ... Scientific and technical encyclopedic dictionary Galaxy- Galaxy. Schematic representation of the Galaxy (edge-on view). GALAXY, star system (spiral galaxy) to which the Sun belongs (to distinguish it from other galaxies, it is written with a capital letter). The galaxy contains at least 1011 stars ... ... Illustrated Encyclopedic Dictionary GALAXY, star system (spiral galaxy) to which the Sun belongs (to distinguish it from other galaxies, it is written with a capital letter). The galaxy contains at least 1011 stars (a total mass of 1011 solar masses), interstellar matter (gas and dust, ... ... Modern Encyclopedia - (from Greek galaktikos milky) star system (spiral galaxy) to which the Sun belongs. The galaxy contains at least 1011 stars (with a total mass of 1011 solar masses), interstellar matter (gas and dust, the mass of which is several ... ... Big Encyclopedic Dictionary GALAXY, and, wives. Giant star system. Our G. (the one to which the Sun belongs). other galaxies. | adj. galactic, oh, oh. Galactic nebulae. Dictionary Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov A galaxy is a large formation of stars, gas, dust, which are held together by the force of gravity. These largest compounds in the universe can vary in shape and size. Most of space objects is part of a particular galaxy. These are stars, planets, satellites, nebulae, black holes and asteroids. Some of the galaxies have a large number of invisible dark energy. Due to the fact that the galaxies are separated by an empty space, they are figuratively called oases in the cosmic desert ..The emergence of galaxies
How galaxies are classified
Origin of the name "Milky Way"
Our Galaxy
Other galaxies
What is a galaxy
What are groups of galaxies
Our place in space
So...
See what "Galaxy" is in other dictionaries:
| elliptical galaxy | spiral galaxy | wrong galaxy | |
|---|---|---|---|
| spheroidal component | entire galaxy | There is | Very weak |
| stellar disk | No or weak | Main component | Main component |
| Gas and dust disk | Not | There is | There is |
| spiral branches | None or only near the core | There is | Not |
| Active cores | Meet | Meet | Not |
| 20% | 55% | 5% |
Our galaxy
Our closest star, the Sun, is one of the billion stars in the Milky Way galaxy. Looking at the night starry sky, it is hard not to notice a wide band strewn with stars. The ancient Greeks called the cluster of these stars the Galaxy.
If we had the opportunity to look at this star system from the side, we would have noticed an oblate ball, in which there are over 150 billion stars. Our galaxy has dimensions that are hard to imagine in your imagination. A beam of light travels from one side of it to the other for a hundred thousand Earth years! The center of our Galaxy is occupied by the core, from which huge spiral branches filled with stars depart. The distance from the Sun to the nucleus of the Galaxy is 30,000 light years. The solar system is located on the outskirts milky way.
Stars in the Galaxy despite a huge cluster space bodies are rare. For example, the distance between the nearest stars is tens of millions of times greater than their diameters. It cannot be said that the stars are scattered randomly in the Universe. Their location depends on the forces of gravity that hold the celestial body in a certain plane. Star systems with their gravitational fields are called galaxies. In addition to stars, the composition of the galaxy includes gas and interstellar dust.
composition of galaxies.
The universe is also made up of many other galaxies. The closest to us are distant at a distance of 150 thousand light years. They can be seen in the sky of the southern hemisphere in the form of small hazy specks. They were first described by a member of the Magellanic expedition around the world of Pigafett. They entered science under the name of the Large and Small Magellanic Clouds.
The closest galaxy to us is the Andromeda Nebula. She has very big sizes, therefore it is visible from the Earth with ordinary binoculars, and in clear weather - even with the naked eye.
The very structure of the galaxy resembles a giant spiral convex in space. On one of the spiral arms, ¾ of the distance from the center, is the solar system. Everything in the galaxy revolves around the central core and obeys the force of its gravity. In 1962, astronomer Edwin Hubble classified galaxies according to their shape. The scientist divided all galaxies into elliptical, spiral, irregular and barred galaxies.
There are billions of galaxies in the part of the Universe available for astronomical research. Collectively, astronomers call them the Metagalaxy.
Galaxies of the Universe
Galaxies are represented by large groupings of stars, gas, dust, held together by gravity. They can vary greatly in shape and size. Most space objects belong to a galaxy. These are black holes, asteroids, stars with satellites and planets, nebulae, neutron satellites.
Most of the universe's galaxies contain vast amounts of invisible dark energy. Since the space between different galaxies is considered empty, they are often called oases in the void of space. For example, a star called the Sun is one of the billions of stars in the "Milky Way" galaxy in our universe. At ¾ of the distance from the center of this spiral is the solar system. In this galaxy, everything is constantly moving around the central core, which obeys its gravity. However, the core also moves along with the galaxy. At the same time, all galaxies move at superspeeds.
Astronomer Edwin Hubble in 1962 carried out a logical classification of the galaxies of the universe, taking into account their shape. Now galaxies are divided into 4 main groups: elliptical, spiral, galaxies with a bar (bar) and irregular.
What is the largest galaxy in our universe?
The largest galaxy in the universe is the super-giant lenticular galaxy in the Abell 2029 cluster.
spiral galaxies
They are galaxies that in their shape resemble a flat spiral disk with a bright center (core). The Milky Way is a typical spiral galaxy. Spiral galaxies are usually called with the letter S, they are divided into 4 subgroups: Sa, So, Sc and Sb. Galaxies belonging to the So group are distinguished by bright nuclei that do not have spiral arms. As for the Sa galaxies, they are distinguished by dense spiral arms tightly wrapped around the central core. The arms of the Sc and Sb galaxies rarely surround the core.
Spiral galaxies in the Messier catalog
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barred galaxies
Barred galaxies are similar to spiral galaxies, but still have one difference. In such galaxies, spirals do not start from the core, but from the bridges. About 1/3 of all galaxies fall into this category. They are usually denoted by the letters SB. In turn, they are divided into 3 subgroups Sbc, SBb, SBa. The difference between these three groups is determined by the shape and length of the bridges, from where, in fact, the arms of the spirals begin.
Messier barred spiral galaxies
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elliptical galaxies
The shape of galaxies can vary from perfectly round to elongated ovals. Their distinguishing feature is the absence of a central bright core. They are designated by the letter E and are divided into 6 subgroups (by shape). Such forms are designated from E0 to E7. The former are almost round in shape, while the E7 are characterized by an extremely elongated shape.
Elliptical galaxies in the Messier catalog
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Irregular galaxies
They do not have any pronounced structure or shape. Irregular galaxies are usually divided into 2 classes: IO and Im. The most common is the Im class of galaxies (it has only a slight hint of structure). In some cases, spiral remnants are traced. IO belongs to a class of galaxies that are chaotic in shape. The Small and Large Magellanic Clouds are a prime example of the Im class.
Messier catalog irregular galaxies
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Table of characteristics of the main types of galaxies
| elliptical galaxy | spiral galaxy | wrong galaxy | |
| spheroidal component | entire galaxy | There is | Very weak |
| stellar disk | No or weak | Main component | Main component |
| Gas and dust disk | Not | There is | There is |
| spiral branches | None or only near the core | There is | Not |
| Active cores | Meet | Meet | No |
| Percentage of total number galaxies | 20% | 55% | 5% |
Large portrait of galaxies
Not so long ago, astronomers began working on a collaborative project to determine the location of galaxies throughout the universe. Their task is to get a more detailed picture of the general structure and shape of the universe on a large scale. Unfortunately, the scale of the universe is difficult to estimate for understanding by many people. Take at least our galaxy, consisting of more than a hundred billion stars. There are billions more galaxies in the universe. Distant galaxies have been discovered, but we see their light as it was almost 9 billion years ago (we are separated by such a large distance).
Astronomers became aware that most galaxies belonged to a particular group (it became known as a "cluster"). The Milky Way is part of a cluster, which, in turn, consists of forty known galaxies. As a rule, most of these clusters are part of an even larger grouping, which is called superclusters.
Our cluster is part of a supercluster commonly referred to as the Virgo Cluster. Such a massive cluster consists of more than 2 thousand galaxies. At the same time that astronomers mapped the location of these galaxies, superclusters began to take shape. Large superclusters have gathered around what appear to be gigantic bubbles or voids. What kind of structure this is, no one knows yet. We do not understand what can be inside these voids. By assumption, they can be filled with a certain type of unknown to scientists. dark matter or have empty space inside. It will be a long time before we know the nature of such voids.
Galactic Computing
Edwin Hubble is the founder of galactic research. He is the first to figure out how to calculate the exact distance to a galaxy. In his research, he relied on the method of pulsating stars, which are better known as Cepheids. The scientist was able to notice the relationship between the period that is needed to complete one pulsation of brightness, and the energy that the star releases. The results of his research were a major breakthrough in the field of galactic research. In addition, he found that there is a correlation between the red spectrum emitted by a galaxy and its distance (the Hubble constant).
Nowadays, astronomers can measure the distance and speed of a galaxy by measuring the amount of redshift in the spectrum. It is known that all galaxies of the Universe move from each other. The further the galaxy is from the Earth, the greater its speed of movement.
To visualize this theory, it is enough to imagine yourself driving a car that moves at a speed of 50 km per hour. A car in front of you is driving faster at 50 km per hour, which indicates that the speed of its movement is 100 km per hour. There is another car in front of him, which is moving faster by another 50 km per hour. Even though the speed of all 3 cars will be 50 km/h different, the first car is actually moving away from you 100 km/h faster. Since the red spectrum indicates the speed of the galaxy moving away from us, the following is obtained: the greater the redshift, the faster the galaxy moves and the greater its distance from us.
Now we have new tools to help scientists in their search for new galaxies. Thanks to the Hubble Space Telescope, scientists have been able to see what they could only dream of before. The high power of this telescope provides good visibility even small parts in nearby galaxies and allows you to study more distant ones that have not yet been known to anyone. Currently, new space observation tools are under development, and in the near future they will help to gain a deeper understanding of the structure of the universe.
Types of galaxies
- spiral galaxies. In shape, they resemble a flat spiral disk with a pronounced center, the so-called core. Our Milky Way galaxy belongs to this category. In this section of the portal site you will find many different articles describing the space objects of our Galaxy.
- Barred galaxies. They resemble spiral ones, only they differ from them in one significant difference. Spirals do not depart from the core, but from the so-called jumpers. This category includes a third of all galaxies in the universe.
- Elliptical galaxies have various forms: from perfectly round to oval elongated. Compared to spiral ones, they lack a central, pronounced core.
- Irregular galaxies do not have a characteristic shape or structure. They cannot be attributed to any of the above types. There are far fewer irregular galaxies in the vastness of the Universe.
Astronomers have recently launched a joint project to identify the location of all galaxies in the universe. Scientists hope to get more clear picture its structures on a grand scale. The size of the universe is difficult to estimate for human thinking and understanding. Our galaxy alone is a connection of hundreds of billions of stars. And there are billions of such galaxies. We can see the light from the discovered distant galaxies, but do not even mean that we are looking into the past, because the light beam reaches us for tens of billions of years, such a great distance separates us.
Astronomers also associate most galaxies with certain groups called clusters. Our Milky Way belongs to a cluster of 40 explored galaxies. Such clusters are combined into large groupings called superclusters. The cluster with our galaxy is part of the Virgo supercluster. This giant cluster contains over 2,000 galaxies. As scientists began to map the distribution of these galaxies, superclusters took on certain shapes. Most of the galactic superclusters were surrounded by giant voids. No one knows what might be inside these voids: outer space like interplanetary or new form matter. It will take a long time to solve this riddle.
Interaction of galaxies
No less interesting for scientists is the question of the interaction of galaxies as components of space systems. It's no secret that space objects are in constant motion. Galaxies are no exception to this rule. Some of the types of galaxies could cause a collision or merger of two space systems. If you look into how these space objects appear, large-scale changes as a result of their interaction become more understandable. During the collision of two space systems, a huge amount of energy splashes out. The meeting of two galaxies in the vastness of the Universe is an even more probable event than the collision of two stars. The collision of galaxies does not always end in an explosion. A small space system can freely pass by its larger counterpart, changing only slightly its structure.
Thus, formations similar to appearance along long corridors. Stars and gas zones stand out in their composition, new luminaries often form. There are times when galaxies do not collide, but only lightly touch each other. However, even such an interaction triggers a chain of irreversible processes that lead to huge changes in the structure of both galaxies.
What is the future of our galaxy?
As scientists suggest, it is possible that in the distant future the Milky Way will be able to absorb a tiny satellite system, which is located at a distance of 50 light years from us. Studies show that this satellite has a long life potential, but if it collides with a giant neighbor, it will most likely end its separate existence. Astronomers also predict a collision between the Milky Way and the Andromeda Nebula. Galaxies move towards each other at the speed of light. Before a likely collision, wait about three billion Earth years. However, whether it will actually happen now is hard to argue due to the lack of data on the motion of both space systems.
Description of galaxiesKvant. Space
The portal site will take you to the world of interesting and fascinating space. You will learn the nature of the construction of the Universe, get acquainted with the structure of known large galaxies and their components. By reading articles about our galaxy, some of the phenomena that can be observed in the night sky become more understandable to us.
All galaxies are at a great distance from the Earth. Only three galaxies can be seen with the naked eye: the Large and Small Magellanic Clouds and the Andromeda Nebula. It is impossible to count all galaxies. Scientists suggest that their number is about 100 billion. The spatial arrangement of galaxies is uneven - one region can contain a huge number of them, in the second there will not be even a single small galaxy at all. Astronomers failed to separate the image of galaxies from individual stars until the early 1990s. At that time, there were about 30 galaxies with individual stars. All of them were assigned to the Local group. In 1990, a majestic event took place in the development of astronomy as a science - the Hubble telescope was launched into Earth's orbit. It is this technique, as well as new ground-based 10-meter telescopes, that made it possible to see a much larger number of resolved galaxies.
Today, the "astronomical minds" of the world are puzzling over the role of dark matter in the construction of galaxies, which manifests itself only in gravitational interaction. For example, in some large galaxies it is about 90% of the total mass, while dwarf galaxies may not include it at all.
Evolution of galaxies
Scientists believe that the emergence of galaxies is a natural stage in the evolution of the Universe, which took place under the influence of gravitational forces. Approximately 14 billion years ago, the formation of protoclusters in the primary matter began. Further, under the influence of various dynamic processes, the separation of galactic groups took place. The abundance of galaxy shapes is explained by the variety of initial conditions in their formation.
It takes about 3 billion years to compress a galaxy. Over a given period of time, the gas cloud turns into a star system. Star formation occurs under the influence of gravitational compression of gas clouds. After reaching a certain temperature and density in the center of the cloud, sufficient for the start of thermonuclear reactions, new star. Massive stars are formed from thermonuclear chemical elements larger than helium in mass. These elements create the primary helium-hydrogen environment. During grandiose explosions of supernovae, elements heavier than iron are formed. It follows from this that the galaxy consists of two generations of stars. The first generation are the oldest stars, consisting of helium, hydrogen and a very small amount of heavy elements. Second-generation stars have a more noticeable admixture of heavy elements, since they are formed from a primordial gas enriched in heavy elements.
In modern astronomy, galaxies as space structures assigned separate place. The types of galaxies, the features of their interaction, similarities and differences are studied in detail, and a forecast of their future is made. This area contains many more incomprehensible things that require further study. Modern science has solved many questions regarding the types of construction of galaxies, but there are also many blank spots associated with the formation of these cosmic systems. The current pace of modernization of research equipment, the development of new methodologies for the study of space bodies give hope for a significant breakthrough in the future. One way or another, galaxies will always be in the center scientific research. And it is based not only on human curiosity. Having received data on the patterns of development of space systems, we will be able to predict the future of our galaxy called the Milky Way.
The most interesting news, scientific, author's articles about the study of galaxies will be provided to you by the portal site. Here you can find breathtaking videos, high-quality images from satellites and telescopes that do not leave you indifferent. Dive into the world of unknown space with us!
