Investigation of the cosmic competition between the large and small Magellanic clouds. Magellanic clouds: who are they? Distance to the Large Magellanic Cloud

Magellanic Clouds

- satellite galaxies of our Galaxy; located relatively close to each other, they form a gravitationally bound (double) system. To the naked eye they look like isolated clouds of the Milky Way. M. O. was first described by Pigafetta, who participated in Magellan’s circumnavigation of the world (1519-22). Both Clouds - Large (LMC) and Small (SMC) - appear. irregular galaxies. The integral characteristics of the MO are given in the table.

Integral characteristics of the Magellanic Clouds

	BMO	MMO
Center coordinates	05 h 24 m -70 o	00 h 51 m -73 o
Galactic latitude	-33 o	-45 o
Angular diameter	8 o	2.5 o
Corresponding linear size, kpk	9	3
Distance, kpk	50	60
Integral value, M V	-17,9m	-16,3m
Inclination to line of sight	27 o	60 o
Average radial velocity, km/s	+275	+163
Total weight,
Mass of interstellar hydrogen HI,

The largest telescopes in the Moscow Ocean can resolve stars with a luminosity close to the Sun; at the same time due to means. when the distance to the MO exceeds their diameter, the difference in the apparent magnitudes of the objects included in the MO is equal to the difference in their absolute magnitude. (for LMC the error does not exceed 0.1 m). Since M.O. are located at high galactic levels. latitudes, the absorption of light by the interstellar medium of our Galaxy and the admixture of its stars little distort the picture of the MO. In addition, the plane of the LMC (Fig. 1) is almost perpendicular to the line of sight, so that the visible proximity of the objects included in it means, as a rule, their spatial intimacy. All this helps to study the relationship between stars of various types, clusters and diffuse matter (in particular, high-luminosity stars are visible there no further than 5-10" from their place of birth). M.O. is called "workshop of astronomical methods" (H. Shapley) , in particular, the period-luminosity relationship was discovered in the M.O. The objects of the M.O., along with their similarities, also have a number of striking differences from similar members of the Galaxy, which indicates a connection between the structural features of galaxies and the characteristics of their population.

In M.O. there is a huge number of all kinds of ages and masses; The catalog of LMC clusters includes 1600 objects, and their total number is ca. 5000. About a hundred of them look like Galaxies and are very close to them in mass and degree of concentration of stars. However, the globular clusters of the Galaxy are all very old [(10-18) years], while in the MO, along with equally old clusters, there are a number of globular clusters (23 in the LMC) with ages of ~10 7 -10 8 years. The age of M.O. clusters clearly correlates with the chemistry. composition (young clusters contain relatively more heavy elements), while clusters of galaxies. disk there is no such correlation.

In the LMC, 120 large groups of young high-luminosity stars (OB associations) are also known, usually associated with regions of ionized hydrogen (HII zones). In the MMO there are an order of magnitude fewer such groups; young stars are mainly concentrated there. body and in the “wing” of the MMO, extended towards the LMC, while in the LMC they are scattered throughout the Cloud, and basically. The body is dominated by stars with an age of 10 8 -10 10 years. Radioastronomical Observations in the line = 21 cm of neutral hydrogen (HI) showed that in the LMC there are 52 isolated HI complexes with avg. mass and size 300-900 pc, and in the MMO the HI density almost uniformly increases towards the center. The share of HI in relation to the total mass in the LMC in several. times more than in the Galaxy, and in MMOs an order of magnitude more. Even in the youngest objects of the LMC, the content of heavy elements is apparently somewhat lower than in the Galaxy; in the SMC it is undoubtedly 2-4 times lower. All these features of the MO can be explained by the fact that there was no initial violent outburst, which led to the exhaustion of basic energy in the Galaxy. gas reserves and the relatively rapid enrichment of its remains with heavy elements during the first billions (or hundreds of millions) of years of the Galaxy’s existence. The presence of old globular clusters and the RR Lyrae type proves, however, that star formation began in the MO and in the Galaxy at approximately the same time. The presence of a large number of young globular clusters in the MO (there are none in the Galaxy) may mean that their formation in modern times. The disk of the Galaxy is hampered by a spiral density wave, which can also initiate star formation in gas clouds that have not reached a high degree of compression (see).

In each of the MOs, ~10 3 Cepheids are known, and the maximum in their distribution over periods is shifted in the IMC to short periods (compared to Cepheids in the Galaxy), which can also be explained by the lower content of heavy elements in the IMC stars. The distribution of Cepheids by periods is not the same in different parts of the MO, which, in accordance with the period-age relationship, is explained by the difference in the age of massive stars in these areas. The diameter of the regions in which Cepheids and clusters have similar ages is 300-900 pc. The objects in these star complexes are obviously genetically related to each other - they arose from the same gas complex.

In several In areas of the Moscow Ocean, stars of the RR Lyrae type have been studied, which in the LMC have avg. magnitude 19.5 m with very small dispersion, which implies a low dispersion of their luminosities and weak absorption of light in the LMC. Few dust nebulae have been found in the LMC (about 70), and only in some areas inside and near the giant HII Tarantula zone (30 Doradus) the absorption reaches 1-2 m. The ratio of the mass of dust to the mass of gas in the LMC is an order of magnitude smaller than in the Galaxy, and the low dust content should be reflected in the features of star formation in the M.O. The shells in the LMC (several dozen are known) are noticeably larger in size at the same surface brightness as and in the Galaxy, their diameters, like the HII ring zones, reach 200 pc. There are 9 supergiant HII shells with a diameter of approx. 1 kpk. In the MO, the closest connection with gas is shown not by 0-stars, but by . It has also been noted that star formation regions in the LMC are, as a rule, located in regions with the highest HI density gradient.

HII zones, supergiants and planetary nebulae (the latter are 137 discovered in the LMC and 47 in the IMC) make it possible to determine the center of rotation of the LMC. It is located 1 kpc from its optical. center. The discrepancy is explained, apparently, by the fact that the latter is determined by bright objects, the mass of which is not apparent. dominant. Rapid rotation and small velocity dispersion (about 10 km/s for young objects) indicate a high degree of oblateness of the LMC (some astronomers consider the LMC to be a spiral galaxy with a massive bar and weakly pronounced spiral arms). Old globular clusters and, apparently, RR Lyrae stars are also concentrated in the disk rather than in the corona of the LMC. The peculiarity of the kinematics of the MMO and the very high surface density of Cepheids in it can be explained by the fact that the MMO is oriented towards us with the end of its main body. body, while the LMC is visible from a direction almost perpendicular to the plane of its disk.

A remarkable feature of the LMC is a stellar superassociation discovered in it, in the center of which there is a giant zone HII (30 Doradus, Fig. 2) with a diameter of approx. 250 pc and mass . In the center of the zone there is a compact cluster of very high luminosity stars with a total mass (Fig. 3). It is revealed. the youngest known globular clusters and contains the most massive young stars. The central object of the cluster is brighter by 2 m the rest of the stars. Apparently, this is a compact group of hot stars exciting the HII region. In a number of characteristics, the 30 Doradus cluster appears to be moderately active

While scientists debate whether the Large and Small Magellanic Clouds are satellites of the Milky Way or just “random passers-by,” these small spiral galaxies calmly continue their vigorous activity. Rushing through the void at unimaginable speeds, they form new stars and exchange resources with us and with each other. They also throw clever puzzles at the scientists!

A little history

The first written mention of the Large Magellanic Cloud is contained in the “Book of Constellations of Fixed Stars” by the Persian astronomer As-Sufi (964). The next observation was recorded only in 1503-1504 by the Florentine traveler Amerigo Vespucci - however, this celestial object was then called the “Cape Clouds”.

The Spanish-Portuguese navigator Ferdinand Magellan used them for navigation, as an alternative to the North Star, during his voyage around the world in 1519-1521. After the death of the expedition leader, his companion and official chronicler Antonio Pigafetta proposed to name the stellar landmark Magellan's clouds as a kind of perpetuation of his memory.

Where does the goldfish live?

A gravitationally bound system of dwarf galaxies is visible to the naked eye in the Southern Hemisphere. The Large Magellanic Cloud (LMC) is located in the constellations Doradus and Table Mountain at a distance of about 50 kiloparsecs from our Galaxy, which is twice the diameter of the Milky Way. The Small Magellanic Cloud (SMC) is located in the constellation Tucana at a distance of about 60 kiloparsecs.

The Large Magellanic Cloud is further proof that “size is not everything.” This galaxy is about 20 times smaller in diameter than the Milky Way and weighs about 300 times less - but it shines only 10 times less (i.e., at the same size it would be 10 times brighter). And there are many reasons for this, starting with the Tarantula Nebula: a kind of “nursery” for thousands of newborn stars spanning 700 light years! And what kind of record-breaking celebrities live here - just cosmic Beverly Hills!

The brightest star in the Large Magellanic Cloud is S Doradus, or S Doradus. This hypergiant is one of the brightest stars known to science: its luminosity exceeds our Sun by 500,000 times. The star WOH G64 is one of the largest known to science: its radius is approximately 1,540 solar radii, so if this “baby” is placed at the center of the solar system, its surface will reach the orbit of Saturn. Another phenomenon is the superheavy blue giant R136a1, whose mass is equal to 265 solar masses. The star's surface temperature is more than 40,000 Kelvin and is several million times brighter than the Sun. Such superheavy stars are generally extremely rare and form only in very dense star clusters.

Robbery in space

The Magellanic Bridge is an interstellar gas flow connecting galaxies. More precisely, it is a rope that has been successfully pulling a larger cloud onto itself for two and a half billion years. The whole point, of course, is the law of gravity: as they say, whoever has gravity has the law! However, the appetites of the Large Magellanic Cloud were clearly not limited to stellar gas...

Astronomers found that some of its stars were... borrowed from the Small Cloud. Moreover, the game was big: The Big Cloud got not just any “fireflies”, but about three hundred orange giants and supergiants! The suspicious speed characteristics of the prey gave the thief away: the stolen stars rotate at an angle of 54 degrees to the plane of the Big Cloud, and also in the opposite direction compared to the bulk of the stars. The chemical composition of these stars also differs (in terms of the percentage of iron they correspond to the Small Cloud).

The Milky Way cheats too

Researchers from the Australian scientific organization CSIRO have discovered and measured a colossal stream of hydrogen that flows from the Magellanic clouds towards our home Galaxy and meets it in the constellation Southern Cross (at a distance of 70 thousand light years from the Sun). This extra-long burst, or gas finger, was named HVC306-2+230.

Astronomers claim that this is nothing more than the tricks of the Milky Way: we are pulling this gas from the Magellanic clouds due to powerful gravity. Moreover, we pull from both neighboring galaxies at once, as evidenced by chemical analysis using spectrographs. Most of the gas contains little oxygen and sulfur, consistent with the composition of the Small Cloud. However, a heavier oxygen-sulfur jet from the Big Cloud was also discovered in the flow...

This casts doubt on the age-old idea that the Magellanic Clouds are satellites of our galaxy. If they had originally formed near the Milky Way, its gravity would have long ago deprived them of interstellar gas. At the very least, scientists believe, this would make the distribution of elements in the “gas finger” much more uniform. This means that the Magellanic clouds arrived in the vicinity of the Milky Way relatively recently, and it is not a fact that they will remain with us forever.

What a shot!

The Large Magellanic Cloud is full of surprises, but such a scale simply does not fit into the head... The dwarf galaxy managed to “spit” in our direction a star that gained a monstrous speed (more than 722 kilometers per second) due to a supernova explosion. The brave “traveler,” given the discreet name HE 0437-5439, has already crossed the space between galaxies, and now continues her journey through the region of the Milky Way filled with “elderly” stars.

In general, scientists already knew about the possibility of such a development of events, but at first this “throwing projectile” caused complete bewilderment: it was detected only recently, and already on “our territory” - and all the data about the star did not fit into the surrounding picture at all ... Scientists intend to more accurately calculate the trajectory of the space fugitive, which will take several more years of observing its movement.

The Small Magellanic Cloud is a small galaxy that, thanks to its unique properties, appears close-up to terrestrial astronomers.

Space is an endless series of worlds. We do not know, and are hardly able to imagine, where it began and how far it extends. Our native Earth, like all objects of the Solar system, occupy a negligibly small volume in the Universe, belonging to the galaxy. Like planets that have moons, it is accompanied by satellites. The retinue of an object of cosmic scale, numbering from 200 to 400 billion luminaries, can become star clusters to match it.

Comet Lemmon and the Small Magellanic Cloud. The globular cluster 47 Tucanae is visible below.

Close accompaniment and close interconnection connected our galaxy and the Small Magellanic Cloud. Inhabitants of southern latitudes can find it in the constellation Tucana. This does not require optical instruments, since the bright stars of the object make the Cloud visible at a distance of about 200 thousand light years, or 60 kiloparsecs.

Appearance of the name

For a long time, this cluster, called the Cape clouds, served as a guide for brave sailors. It received its modern name at the beginning of the 16th century, after a description made by the companion of the first round-the-world traveler Ferdinand Magellan, his permanent chronicler Antonio Pyphagetta. After the expedition returned to Europe, it was he who proposed to perpetuate the name of the explorer who had already died by that time, paying tribute to his memory.

System structure

This dwarf galaxy was initially thought to have an irregular shape because it failed to develop a spiral or elliptical structure after its formation. This phenomenon is not uncommon; it is explained by the young age of formation, the low density of its matter, or the influence of a larger galaxy, which prevents the creation of a strict system. Subsequent observations identified the symbiosis of the Small and , classified as a special category of barred spiral galaxies. In astronomy it is designated SBm.

General properties

Magellanic flux in the radio range

The cloud was not filled with stars as compactly as our Galaxy; their number was 1.5 billion objects. The SMC (Small Magellanic Cloud) is its third satellite in distance from the Milky Way. Excellent opportunities for observing the system in the night sky are explained by its high apparent magnitude of 2.2. Two Clouds, Large and Small, have a common hydrogen shell, in which the percentage of this gas is higher than in our system. They are connected to each other by a jumper, which is called the Magellan Bridge. Through this gas flow, a larger formation pulled some objects from a neighboring galaxy.

The Small Cloud is half the size of its Big Brother, its diameter is 14 thousand light years. The star formation process in the cluster has not yet completed, although the limited amount of free gas makes it less intense than during the birth of the SMC. Young star clusters include hot stars that are 300 thousand times brighter than our Sun.

MMO objects

Observations of newly formed objects with variable brightness, cephedes, discovered in the MMC, became the basis for the most reliable method for calculating distances to cosmic bodies. Only the emerging clusters observed in this dwarf galaxy are of great interest. Nebula N81 became the place that gave life to several massive stars. Such a birth is always accompanied by a halo of luminous gas and a release of energy. More advanced telescopes today make it possible to observe similar processes occurring at a distance of 200 thousand light years.

There is reason to believe that in the Small Magellanic Cloud cluster there is a unique Wolf-Rayet star, which is experiencing the final stage of its cosmic life. After some time it will explode as a supernova. Despite the close connection between the Clouds, the types of their stars have serious discrepancies, since they were formed during different periods of the existence of galaxies. This is one of the serious arguments in favor of the theory that at the beginning of their history the Magellanic Clouds were not connected by gravity.

According to scientists, the connection of two dwarf galaxies - the Large and Small Clouds - occurred almost 300 million years ago. The MMO suffered significantly from this collision - it lost 5% of its stars. The study of cosmic objects filling this small galaxy is not hampered by the effect of light absorption, so it is easier to understand the mysteries of its stars than our own. Earth scientists predict a sad future for the Magellanic Cloud system: in 4 billion years it will be swallowed up by the Milky Way and it will cease to exist. It is impossible to observe the MMO in the Northern Hemisphere; to see it, you need to cross the equator.

Magellanic Clouds- satellite galaxies of the Milky Way. Both the Large Magellanic Cloud and the Small Magellanic Cloud 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. Visible to the naked eye in the Southern Hemisphere. One of the first descriptions was given by Antonio Pigafetta, a participant in Ferdinand Magellan's (-) circumnavigation of the world. . Both Clouds float in a common hydrogen shell.

The Magellanic clouds are located at high galactic latitudes, so the light from them is little absorbed by our Galaxy, moreover, the plane of the Large Magellanic Cloud is almost perpendicular to the line of sight, so for objects visible nearby it will often be true to say that they are close spatially. These features of the Magellanic clouds made it possible to study the patterns of distribution of stars and star clusters using their example.

The Magellanic clouds have a number of features that distinguish them from the Galaxy. For example, star clusters with ages of 10 7 -10 8 years have been discovered there, while Galaxy clusters are usually older than 10 9 years. Also, the Magellanic clouds appear to have lower contents of heavy elements.

see also

Notes

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See what "Magellanic clouds" are in other dictionaries:

- (named after the traveler Magellan). Foggy spots in the sky, near the south pole, are visible to the naked eye. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. MAGELLANIC CLOUDS named after Magellan two... ... Dictionary of foreign words of the Russian language

- (Big and Small) two galaxies close to us, satellites of the Galaxy. The Magellanic Clouds are visible in the Southern Hemisphere sky with the naked eye (in the constellations Doradus and Tucana, respectively). In the B. Magellanic cloud in February 1987... ... flared up. Big Encyclopedic Dictionary

MAGELLANIC CLOUDS, the two closest GALAXIES to us, visible to the naked eye as separate parts of the Milky Way in the sky in the form of the letter S. The Large Magellanic Cloud is located in the constellations Doradus and Table Mountain, the Small Magellanic Cloud... ... Scientific and technical encyclopedic dictionary

- ... Wikipedia

- (Big and Small) two star systems (Galaxies) of irregular shape, closest to our star system (Galaxy (See Galaxy)), which includes the Sun. Visible in the Southern sky with the naked eye in the form of hazy spots (on... ... Great Soviet Encyclopedia

- (Big and Small), two galaxies close to us, satellites of the Galaxy. Magellanic clouds are visible in the sky in the Southern Hemisphere with the naked eye (in the constellations Doradus and Tucana, respectively). Their discovery is attributed to one of the participants... ... encyclopedic Dictionary

- (Big and Small) two galaxies close to us, satellites of the Galaxy. The Magellanic Clouds are visible in the Southern Hemisphere sky with the naked eye (in the constellations Doradus and Tucana, respectively). In the Large Magellanic Cloud in February 1987, a... Astronomical Dictionary

- (Nubecula major and N. minor) wonderful nebulous spots lying in the southern hemisphere of the sky in the constellations Dorado and Tucan, at a distance of about 20° from one another. M. clouds are not continuous spots like others; they represent the most amazing... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

- (Big and Small), two galaxies close to us, satellites of the Galaxy. M.O. visible in the sky in the South. hemispheres with the naked eye (respectively in the constellations Doradus and Toucan). Their discovery is attributed to one of the participants in the circumnavigation of the world... ... Natural science. encyclopedic Dictionary

Magellanic Clouds- Magellan Clouds a, Magellan Clouds (astro.) ... Russian spelling dictionary

If you ever happen to spend a night south of the Earth's equator, and the southern velvet-black sky spreads unusual patterns of constellations before you (for some reason you always want to believe that somewhere there, beyond the seas, the weather is always good), pay attention to two small foggy clouds in the sky. These “abnormal” clouds do not move relative to the stars and are, as it were, “glued” to the sky.

In Europe, mysterious clouds were known back in the Middle Ages, and the indigenous inhabitants of the equatorial regions and lands of the southern hemisphere apparently knew about them long before that. In the 15th century, sailors called the clouds Cape (the name is akin to the name of the Cape Colony - medieval British possessions in South Africa, located on the territory of the present Republic of South Africa).

The south pole of the world, unlike the north, is more difficult to find in the sky, since there are no such bright and noticeable stars near it as Polaris. The Cape Clouds are located near the south pole of the celestial sphere and form an almost equilateral triangle with it. This property of Clouds made them quite well-known objects, and therefore they have long been used in navigation. However, their nature remained a mystery to scientists of that time.

During Ferdinand Magellan's trip around the world in 1518-1520, his companion and chronicler Antonio Pigafetta described the clouds in his travel notes, which made the fact of their existence known to the wider European public. After Magellan died in 1521 in an armed conflict with the local population in the Philippines, Pigafetta proposed calling the clouds Magellanic - Large and Small, according to their size.

Visible to the eye, the size of the Magellanic Clouds in the sky is one of the largest among all astronomical objects. The Large Magellanic Cloud (LMC) has an extent of more than 5 degrees, i.e. 10 apparent diameters of the Moon. The Small Magellanic Cloud (SMC) is slightly smaller - just over 2 degrees. In photographs, where it is possible to record weak outer regions, the sizes of the Clouds are 10 and 6 degrees, respectively. The Small Cloud is located in the constellation Tucana, and the Large Cloud occupies part of Doradus, as well as Table Mountain.

Even at the beginning of our century, scientists did not have a common opinion about the nature of the Clouds. In the encyclopedia of Brockhaus and Efron, for example, it is said that Clouds are “not continuous spots like others; they represent the most amazing accumulations of many nebulous spots, star heaps and individual stars.” And only after astronomers measured the distances to some nebulae in the 20s of the 20th century, and it became clear that there were star worlds lying far beyond the boundaries of our Galaxy, the Magellanic Clouds occupied their “niche” among celestial objects.

It is now known that the Magellanic Clouds are the closest neighbors of our Galaxy in the entire Local Group of galaxies. Light from the LMC takes 230 thousand years to reach us, and from the MMC it takes even less - “only” 170 thousand years. By comparison, the closest giant spiral galaxy is the Andromeda Nebula, almost 10 times further away than the LMC. The linear dimensions of the Clouds are relatively small. Their diameters are 30 and 10 thousand light years (recall that our Galaxy is more than 100 thousand light years across).

The clouds have a shape and structure typical of irregular galaxies: irregularly distributed areas of increased brightness stand out against the background of a ragged structure. And yet there is order in the structure of these galaxies. In the LMC, for example, there is an orderly movement of stars around the center, which makes this Cloud look like “regular” spiral galaxies, the stars in the galaxy are concentrated towards a plane called the galactic plane.

By the movement of the matter of the Clouds, you can find out how their galactic planes are located. It turned out that the LMC lies almost “flat” on the celestial sphere (inclination less than 30 degrees). This means that all the complex “stuffing” of the Big Cloud - stars, clouds of gas, clusters - are located at almost the same distance from us, and the observed difference in the brightness of different stars corresponds to reality and is not distorted due to different distances to them. In our Galaxy, only stars in clusters have this property.

The successful orientation of the LMC, its “openness,” as well as the proximity of the Magellanic Clouds to us, made them a real astronomical laboratory, “object number 1” for the physics of stars, star clusters and many other interesting objects.

The Magellanic Clouds have presented several surprises to astronomers. One of them was star clusters. They were discovered in the Magellanic Clouds, just like in our Galaxy. About 2000 of them were found in the MMC, more than 6000 in the LMC, of ​​which about a hundred are globular clusters. There are several hundred globular clusters in our Galaxy, and all of them contain anomalously few chemical elements heavier than helium. In turn, the content of metals clearly depends on the age of the object - after all, the longer stars live, the longer they enrich the “environment” with chemical elements heavier than helium. The low content of metals in the stars of globular clusters of our stellar system suggests that their age is very advanced - 10-18 billion years. These are the oldest objects in our Galaxy.

A surprise awaited astronomers who measured the “metallicity” of clusters in the Clouds. More than 20 globular clusters have been discovered in the LMC, which have the same metal content as stars that are not yet very old. This means that, by the standards of astronomical objects, the clusters were born not so long ago. There are no such objects in our Galaxy! Consequently, the formation of globular clusters continues in the Magellanic Clouds, while in the Galaxy this process stopped many billions of years ago. Most likely, the giant tidal forces in our star system manage to “pull apart” the unborn globular clusters. In the Magellanic Clouds, which are small in size and mass, in a more “polite” environment, there are all the conditions for the formation of globular star clusters.

The Clouds themselves do not stand out in the world of galaxies due to their modest size and luminosity. However, there is an object in the Large Magellanic Cloud that is a prominent figure among its kind. We are talking about a huge, hot and bright cloud of gas, which is clearly visible in photographs of the LMC. It's called the Tarantula Nebula, or more officially 30 Doradus. The name Tarantula was given to the nebula because of its appearance, in which a person with a rich imagination can see the resemblance to a large spider. The length of the nebula is about a thousand light years, and the total mass of gas is 5 million times the mass of the Sun. Tarantula glows like several thousand stars combined. This happens because massive, hot stars are born inside the nebula, emitting much more energy than stars like our Sun. They heat the gas around them and cause it to glow. In our galaxy there are only a few nebulae of similar size, but they are all hidden from us by a dense curtain of galactic dust. If not for the dust, they too would be noticeable and bright celestial objects.

Inside the Tarantula Nebula there are many centers of star birth, where stars are born "in bulk." Young massive stars, less than a few million years old, show us those regions where star formation from gas clumps is still ongoing.

There have also been multiple supernova explosions inside Tarantula. Such explosions of stars at the final stage of their evolution lead to the fact that most of the star is scattered throughout space at speeds of several thousand kilometers per second. Supernova explosions made the structure of the nebula confusing, chaotic, filled with intersecting gas filaments and shells. The Tarantula Nebula serves as a good testing ground for testing theories of the birth and death of stars.

The Magellanic Clouds also played an important role in the construction of the intergalactic distance scale. Over 2000 variable stars have been found in the Clouds, most of which are Cepheids. The period of change in the brightness of Cepheids is closely related to their luminosity, which makes these stars one of the most reliable indicators of the distance to galaxies. Using the Clouds as an example, it is very convenient to compare various distance indicators, which are used to construct an intergalactic “ladder” of distances.

If the human eye were capable of perceiving radio waves with a wavelength of 21 cm (at this wavelength atomic hydrogen emits), it would see an amazing picture in the sky. He would have seen dense clouds of gas in the plane of our Galaxy - the Milky Way, and individual clouds at different latitudes - nearby gas nebulae and clouds "wandering" at high latitudes. The Magellanic Clouds would change amazingly. Instead of two separated objects, a “long-wavelength” person would see one large cloud with two bright condensations where we are accustomed to seeing the Large and Small Magellanic Clouds.

Back in the 50s, it was found that the clouds are immersed in a common gas shell. The shell gas continuously circulates: cooling in intergalactic space, it falls onto the Clouds under the influence of gravity and is pushed back by the “pistons” of supernovae, as a result of the explosion of which an expanding shell of hot gas with excess pressure inside appears (this process is reminiscent of the movement of water in a pan heated from below gas burner).

It has also recently become clear that the Clouds are connected by a common gas bridge not only to each other. A gas filament was found - a thin strip of gas starting at the Clouds and running across the entire sky. It links the Magellanic Clouds with our Galaxy and several other galaxies in the Local Group. It was called the "Magellanic Stream". How was this stream formed? Most likely, several billion years ago the Magellanic Clouds came close to our Galaxy. Our giant star system “pulled” part of the gas from the Clouds with its gravitational pull, like a vacuum cleaner. This gas partially enriched our star system. The rest of it “splashed out” in intergalactic space, forming the Magellanic Stream.

The proximity of the Magellanic Clouds to our massive Galaxy is not in vain for them. It is possible that the convergence of the Clouds and the Milky Way, causing the exchange of gas and stars, occurred more than once in the past. If the nearest cloud, the Small one, comes 3 times closer to our Galaxy than it is now, tidal forces will completely destroy it. In the distant future, similar collisions may occur, and the Magellanic Clouds will be completely absorbed by our Milky Way. They will not soon be “digested” in the huge belly of our Galaxy, and will activate the birth of stars in the places where they fall, as is observed in a stronger form during the merger of large galaxies.