The universe is huge and exciting. It is difficult to imagine how small the Earth is in comparison with the cosmic abyss. According to the most conservative assumptions of astronomers, there are 100 billion galaxies, and the Milky Way is just one of them. As for the Earth, there are 17 billion such planets in the Milky Way alone ... and this is not counting others that are radically different from our planet. And among the galaxies that have become known to scientists today, there are very unusual ...
In general, I am without much trust and with a fair amount of skepticism about such information. Firstly, we will never get there, and no one will fly to us from there, and in general, maybe everything looks and does not happen exactly as we imagined here. And in general, now there may be something else in that place, because the light of these galaxies has just reached us.
But still, here are 25 interesting samples ...
1. Messier 82
M82 is five times brighter than the Milky Way.
Messier 82, or simply M82, is a galaxy five times brighter than the Milky Way. This is due to the very rapid process of the birth of young stars in it - they appear 10 times more often than in our galaxy. The red plumes emanating from the center of the galaxy are glowing hydrogen gas that is ejected from the center of M82.
2. Galaxy sunflower
A sunflower galaxy: as if from a painting by Vincent Van Gogh
Formally known as Messier 63, this galaxy has been nicknamed the Sunflower because it looks like it came from a painting by Vincent Van Gogh. Its bright, sinuous "petals" are composed of newly formed blue-white giant stars.
3. MACS J0717
Cluster of galaxies MACS J071.
MACS J0717 is one of the strangest galaxies known to scientists. Technically, this is not one stellar object, but a cluster of galaxies - MACS J0717 formed by the collision of four other galaxies. Moreover, the collision process has been going on for more than 13 million years.
4. Messier 74
Messier 74 is a galaxy for Santa.
If Santa Claus had a favorite galaxy, it would clearly become Messier 74. Astronomers often remember about it during the Christmas holidays, because the galaxy is very similar to the Christmas wreath.
5. Galaxy Baby Boom
Every 2 hours is a new star.
About 12.2 billion light-years from Earth, the baby boom galaxy was discovered in 2008. She got her nickname due to the fact that new stars are born incredibly quickly in her - about every 2 hours.
For example, in the Milky Way, a new star appears every 36 days on average.
6. Milky Way
The galaxy we live in.
Our Milky Way Galaxy (which contains the Solar System, and, accordingly, the Earth) is indeed one of the most remarkable galaxies known to scientists in the Universe. It contains at least 100 billion planets and about 200-400 billion stars, some of which are among the oldest in the known universe.
7.IDCS 1426
Cluster of galaxies IDCS 1426.
Thanks to the cluster of galaxies IDCS 1426, today you can see what the universe was two-thirds younger than it is now. IDCS 1426 is the most massive galaxy cluster in the early universe, with a mass of about 500 trillion suns. The bright blue galactic core made of gas is the result of the collision of galaxies in this cluster.
8.I Zwicky 18
The dwarf blue galaxy I Zwicky 18 is the youngest known galaxy. It is only 500 million years old (the Milky Way is 12 billion years old) and it is essentially embryonic. It is a giant cloud of cold hydrogen and helium.
9. NGC 6744
NGC 6744 is a large spiral galaxy.
NGC 6744 is a large spiral galaxy, which astronomers believe is one of the most similar to our Milky Way. The galaxy, located about 30 million light-years from Earth, has an elongated core and spiral arms that are surprisingly identical to the Milky Way.
10. NGC 6872
The galaxy known as NGC 6872 is the second largest spiral galaxy ever discovered by scientists. Many regions of active star formation were found in it. Since there is practically no free hydrogen left in NGC 6872 for the formation of stars, it "sucks" it from the neighboring galaxy IC 4970.
11. MACS J0416
4.3 billion light years from Earth.
Found 4.3 billion light-years from Earth, MACS J0416 is more like some kind of light show at a trendy disco. In fact, behind the vibrant purple and pink colors is a colossal event - the collision of two galaxy clusters.
12.M60 and NGC 4647 - a galactic pair
M60 and NGC 4647 are a galactic pair.
Although gravitational forces pull most galaxies together, there is no evidence that this is the case with neighboring Messier 60 and NGC 4647.
However, there is also no evidence that they are moving away from each other. Like a couple who have lived together for a long time, these two galaxies soar side by side through the cold and dark space.
13. Messier 81
A spiral galaxy with a supermassive black hole.
Located near Messier 25, Messier 81 is a spiral galaxy with a supermassive black hole at its center and 70 million times the mass of the Sun. M81 is home to many short-lived but very hot blue stars.
The gravitational interaction with M82 caused plumes of hydrogen gas to stretch between the two galaxies.
14. Galaxies-antennas
Galaxies-antennas
About 600 million years ago, the galaxies NGC 4038 and NGC 4039 crashed into each other, beginning to massively exchange stars and galactic matter. Because of their appearance, these galaxies are called antennas.
15. Sombrero Galaxy
One of the most popular galaxies.
The Sombrero Galaxy is one of the most popular among amateur astronomers. It got its name from the fact that, thanks to its bright core and large central bulge, it looks like this headdress.
16.2MASX J16270254 + 4328340
A fine mist composed of millions of stars.
This galaxy, diffuse in all images, is known under the rather complicated name 2MASX J16270254 + 4328340. As a result of the merger of two galaxies, a "fine mist consisting of millions of stars" was formed. This "fog" is believed to be slowly dissipating as the galaxy expires.
17. NGC 5793
Galaxy with masers.
Not too strange (albeit very beautiful) at first glance, spiral galaxy NGC 5793 is better known for its rare phenomenon: masers. People are familiar with lasers that emit light in the visible region of the spectrum, but few know about masers that emit light in the microwave range.
18. Galaxy of the Triangle
Nebula NGC 604.
The photo shows the nebula NGC 604, located in one of the spiral arms of the galaxy Messier 33. More than 200 very hot stars heat the ionized hydrogen in this nebula, causing it to fluoresce.
19. NGC 2685
NGC 2685 is one of the rare varieties of galaxies.
Also sometimes referred to as a spiral galaxy, NGC 2685 lies in the constellation Ursa Major. One of the first polar ring galaxies to be found, NGC 2685 has an outer ring of gas and stars orbiting the galactic poles, making it one of the rarest galaxy species. Scientists still don't know what causes these polar rings to form.
20. Messier 94
A galaxy that looks like a hurricane.
Messier 94 looks like a terrible hurricane that was shot from orbit on Earth. This galaxy is surrounded by bright blue rings of actively forming stars.
21. Pandora's Cluster
A galaxy in chaos.
Formally known as Abell 2744, this galaxy was nicknamed the Pandora Cluster due to a range of strange phenomena arising from the collision of several smaller galaxy clusters. Real chaos is going on in it.
22. NGC 5408
The Wrong Spy Galaxy
Most galaxies have a majestic spiral or elliptical shape. However, about a quarter of galaxies "ignore" such common structures. Known as irregular galaxies, this is the group that includes NGC 5408, which was imaged by the Hubble telescope.
The English astronomer John Frederick William Herschel discovered the irregular galaxy NGC 5408, located 16 million light years away in the constellation Centaurus, in June 1834.
Another sign of NGC 5408, confirming its "incorrectness", is an ultra-bright X-ray source called NGC 5408 X-1. These rare objects emit mind-boggling amounts of X-rays of enormous energy.
Astrophysicists consider them to be candidates for intermediate-mass black holes. This hypothetical type of black hole has a significantly lower mass than the supermassive black holes found in galactic centers, but at the same time they are much heavier than black holes of stellar mass.
23. Whirlpool Galaxy
Whirlpool Galaxy
The Whirlpool Galaxy, officially known as M51a or NGC 5194, is large enough and close to the Milky Way to be visible in the night sky even with binoculars. It was the first classified spiral galaxy and is of particular interest to scientists due to its interaction with the dwarf galaxy NGC 5195.
24.SDSS J1038 + 4849
SDSS J1038 + 4849
The SDSS J1038 + 4849 galaxy cluster is one of the most attractive clusters ever found by astronomers. It looks like a real smiley in space. The eyes and nose are galaxies, and the curved mouth line is due to gravitational lensing.
25. NGC3314a and NGC3314b
Nearly colliding galaxies.
While these two galaxies look like they are colliding, this is actually an optical illusion. There are tens of millions of light years between them.
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Galaxy Is a huge rotating star system. In addition to our Galaxy, there are a great many others, diverse both in appearance and in physical characteristics.
Large galaxies are usually separated from each other in space by distances of several megaparsecs. Parsec(Russian abbreviation: pc; international abbreviation: pc) is a non-systemic unit of distance measurement common in astronomy. 1pc = 3.2616 light years... Small galaxies are often found near giant galaxies and are their companions. This image shows spiral galaxy NGC 4414 in the constellation Coma Berenica, about 17,000 parsecs in diameter, about 20 megaparsecs from Earth.
Can other galaxies be seen with the naked eye?
Yes, you can. But only those closest to us. These are three galaxies: the Large and Small Magellanic Clouds and the Andromeda Nebula. With great difficulty, one can see the Triangulum Galaxy and the Bode Galaxy. Other galaxies can be seen through a telescope as hazy spots of various shapes - these are extremely distant objects. Even the distance to the nearest ones is usually measured in megaparsecs.
How many galaxies are there?
It is impossible to give an exact amount. But images of deep space, taken in the early 1990s with the Hubble Space Telescope, clearly show that there are hundreds of billions of galaxies... There are galaxies with their own names, for example, the names of galaxies already given in this article, as well as galaxies Spindle, Tadpole, Antennas, Mice, Sunflower, Cigar, Fireworks, Sculptor, Sleeping Beauty, etc. Some galaxies are indicated only by letters and numbers: galaxy M82 , galaxy М102, galaxy NGC 3314A, etc.
As mentioned above, galaxies are diverse in shape: among them one can distinguish spherical elliptical galaxies, disk spiral galaxies, galaxies with a bar (bar), dwarf, irregular, etc. Their mass varies from 107 to 1012 solar masses. Let's compare: the mass of our galaxy, the Milky Way, is equal to 2 1011 solar masses. The diameter of galaxies is also varied: from 16 to 800 thousand light years. For comparison: the diameter of our galaxy is about 100,000 light years.
Structure of galaxies
We already know that a galaxy is a giant gravitationally bound system of stars and star clusters, interstellar gas and dust, and dark matter. We also know that dark matter is inaccessible for direct observation by modern means of astronomy, because does not emit electromagnetic or neutrino radiation for intensity observations and does not absorb them. Therefore, it is one of the unsolved problems of the structure of galaxies. It can account for up to 90% of the total mass of the galaxy, or it can be completely absent, as in some dwarf galaxies.
In space, galaxies are unevenly distributed: in one region there may be a whole group of nearby galaxies, but you may not find a single galaxy, even the smallest one (the so-called voids).
Classification of galaxies
The classification introduced by Hubble is currently in use. It is based on the appearance of galaxies and divides them into three classes: elliptical, spiral and irregular... In part, this classification includes physical differences.
Elliptical (type E) have the shape of an ellipsoid. The spatial density of stars in them decreases uniformly from the center to the periphery. Most of them are almost devoid of interstellar gas, so there is no formation of young stars, they are composed of old stars like the Sun. Their rotation occurs at a low speed (less than 100 km / sec.). But it is among the ellipticals that the most massive galaxies are found.
Spiral (type S) consist, as it were, of two subsystems: spherical and disk. The first resembles an elliptical galaxy, the disk is highly compressed and contains, in addition to old, young stars and interstellar gas and dust. The stars of the disk and clouds of gas revolve around the center of the galaxy at a speed of 150-300 km / sec. Denser clouds of gas and young stars are concentrated in spiral arms that emerge either from the core or from the ends of the light bar (bar) crossing the core. This is our Milky Way galaxy. The spiral galaxy also includes the Andromeda Nebula.
Incorrect (type Ir) have a relatively small mass and size, are characterized by a clumpy structure - this is due to the presence of several foci of star formation. The Magellanic Clouds belong to this type of galaxies.
There are still intermediate types of galaxies: lenticular, dwarf, compact, radio galaxies (with intense radio emission), Seyfert (spiral, in the nuclei of which active processes are observed).
Large galaxies meet in pairs or groups: for example, Local group of galaxies... There are interacting galaxies discovered by astronomer B.A. Vorontsov-Velyaminov are tight groups in which galaxies almost touch each other or even penetrate each other. The shape of such galaxies is greatly distorted.
Clusters of galaxies(associations of several hundred galaxies) are usually spherical or ellipsoidal in shape. The nearest cluster of galaxies is located in the constellation Virgo, it is the center of the Local Supercluster of galaxies - a system that unites several clusters of galaxies, including the Local Group. Superclusters(thousands of galaxies) are usually flat or cigar-shaped. As established by astronomers, galaxies scatter, i.e. the distances between clusters and superclusters are constantly increasing. This is due to the expansion of the universe.
Our Galaxy is one of the galaxies of the Local Group, dominating it along with Andromeda. The Local Group contains more than 40 galaxies about 1 megaparsec across. The Local Group itself is part of the Virgo Supercluster, in which the Virgo cluster plays the main role, which our Galaxy is not part of.
Since ancient times, the starry sky has attracted the eyes of people. The best minds of all peoples tried to comprehend our place in the Universe, to imagine and justify its structure. Scientific progress made it possible to move in the study of the vast expanses of space from romantic and religious constructions to logically verified theories based on numerous factual material. Now any schoolchild has an idea of what our Galaxy looks like according to the latest research, who, why and when gave it such a poetic name and what its supposed future is.
origin of name
The expression "Milky Way galaxy" is essentially a tautology. Galactikos roughly translated from ancient Greek means "milk". So the inhabitants of the Peloponnese called the cluster of stars in the night sky, attributing its origin to the hot-tempered Hera: the goddess did not want to feed Hercules, the illegitimate son of Zeus, and in anger sprayed breast milk. The drops formed a star track, visible on clear nights. Centuries later, scientists discovered that the observed luminaries are only an insignificant part of the existing celestial bodies. The space of the Universe, in which our planet is located, they gave the name Galaxy or the Milky Way system. After confirming the assumption of the existence of other similar formations in space, the first term became universal for them.
Inside view
Scientific knowledge about the structure of the part of the universe, including the solar system, took little from the ancient Greeks. Understanding what our Galaxy looks like has evolved from the spherical universe of Aristotle to modern theories, in which there is a place for black holes and dark matter.
The fact that the Earth is an element of the Milky Way system imposes certain restrictions on those who are trying to figure out what shape our galaxy has. An unambiguous answer to this question requires a view from the side, and at a great distance from the object of observation. Now science is deprived of such an opportunity. Collecting data on the structure of the Galaxy and correlating them with the parameters of other space systems available for study is becoming a kind of substitute for an outside observer.
The collected information allows us to say with confidence that our Galaxy has the shape of a disk with a thickening (bulge) in the middle and spiral arms diverging from the center. The latter contain the brightest stars in the system. The disk is over 100,000 light years in diameter.
Structure
The center of the Galaxy is hidden by interstellar dust, which makes it difficult to study the system. The methods of radio astronomy help to cope with the problem. Waves of a certain length can easily overcome any obstacle and allow you to get the much desired image. Our Galaxy, according to the data obtained, has an inhomogeneous structure.
Conventionally, we can distinguish two elements connected with each other: the halo and the disk itself. The first subsystem has the following characteristics:
- in form it is a sphere;
- its center is the bulge;
- the highest concentration of stars in the halo is characteristic of its middle part, with approaching the edges the density decreases greatly;
- the rotation of this zone of the galaxy is rather slow;
- the halo contains mostly old stars with a relatively low mass;
- a significant space of the subsystem is filled with dark matter.
In terms of the density of stars, the galactic disk greatly exceeds the halo. In the sleeves, there are young and even just emerging
Center and core
The "heart" of the Milky Way is in. Without studying it, it is difficult to fully understand what our Galaxy is like. The name "core" in scientific writings either refers only to the central region with a diameter of only a few parsecs, or includes the bulge and the gas ring, which is considered the birthplace of stars. In what follows, the first version of the term will be used.
Visible light barely penetrates the center of the Milky Way as it collides with a large amount of cosmic dust that obscures what our galaxy looks like. Photos and images taken in the infrared range significantly expand the knowledge of astronomers about the core.
Data on the features of radiation in the central part of the Galaxy prompted scientists to believe that there is a black hole in the core of the nucleus. Its mass is more than 2.5 million times that of the Sun. Around this object, according to the researchers, another, but less impressive in its parameters, black hole revolves. Modern knowledge about the features of the structure of the cosmos suggests that such objects are located in the central part of most galaxies.
Light and darkness
The joint influence of black holes on the motion of stars makes its own adjustments to the way our Galaxy looks: it leads to specific changes in orbits, uncharacteristic of cosmic bodies, for example, near the solar system. The study of these trajectories and the ratio of the velocities of motion with the distance from the center of the Galaxy formed the basis of the now actively developing theory of dark matter. Its nature is still shrouded in mystery. The presence of dark matter, presumably constituting the overwhelming part of all matter in the Universe, is recorded only by the effect of gravity on the orbits.
If you scatter all the cosmic dust that hides the core from us, a striking picture will open to the eye. Despite the concentration of dark matter, this part of the universe is full of light emitted by a huge number of stars. There are hundreds of times more of them here per unit of space than near the Sun. Roughly ten billion of these form a galactic bar, also called a bridging bar, not quite the usual shape.
Space nut
Examining the center of the system at long wavelengths yielded a detailed infrared image. Our Galaxy, as it turned out, has a structure in the core that resembles an inshell peanut. This "nut" is the bridge, which includes more than 20 million red giants (brighter, but less hot stars).
The spiral arms of the Milky Way radiate from the ends of the bar.
Work related to the discovery of "peanuts" in the center of the star system, not only shed light on what our Galaxy is in structure, but also helped to understand how it evolved. Initially, an ordinary disk existed in space, in which a bridge formed over time. Under the influence of internal processes, the bar changed its shape and began to resemble a nut.
Our home on the space map
The active takes place both in the bridge and in the spiral arms that our Galaxy possesses. They were named after the constellations where the branches were found: the arms of Perseus, Cygnus, Centaurus, Sagittarius and Orion. The solar system is located close to the latter (at a distance of at least 28 thousand light years from the core). This area has certain characteristics, according to experts, which made possible the emergence of life on Earth.
The galaxy and our solar system rotate with it. In this case, the patterns of movement of individual components do not coincide. stars from time to time is included in the spiral branches, then separated from them. Only the luminaries lying on the border of the corotation circle do not make such "journeys". These include the Sun, which is protected from powerful processes constantly occurring in the arms. Even a slight shift would negate all other benefits for the development of organisms on our planet.
The sky is in diamonds
The Sun is just one of many similar bodies with which our Galaxy is full. Stars, single or grouped, total more than 400 billion according to the latest data. The nearest to us Proxima Centauri is included in a system of three stars, along with slightly more distant Alpha Centauri A and Alpha Centauri B. The brightest point of the night sky, Sirius A, is located in According to various sources, its luminosity exceeds the solar one by 17-23 times. Sirius is also not alone, it is accompanied by a satellite bearing the same name, but marked B.
Children often begin to get acquainted with what our Galaxy looks like by searching the sky for the Pole Star or Alpha Ursa Minor. It owes its popularity to its position over the North Pole of the Earth. In terms of luminosity, Polaris significantly exceeds Sirius (almost two thousand times brighter than the Sun), but it cannot dispute the right of Alpha Canis Major to the title of the brightest due to its distance from Earth (estimated from 300 to 465 light years).
Types of luminaries
Stars differ not only in luminosity and distance from the observer. Each is assigned a certain value (the corresponding parameter of the Sun is taken as a unit), the degree of surface heating, and color.
Supergiants have the most impressive dimensions. Neutron stars have the highest concentration of matter per unit volume. Color performance is inextricably linked to temperature:
- the red ones are the coldest;
- heating the surface to 6,000º, like the Sun, gives rise to a yellow tint;
- white and blue luminaries have a temperature of over 10,000º.
It can change and reach its maximum shortly before its collapse. Supernova explosions make a huge contribution to understanding what our galaxy looks like. The photos of this process taken with telescopes are amazing.
The data collected on their basis helped to reconstruct the process that led to the outbreak and predict the fate of a number of cosmic bodies.
The future of the Milky Way
Our Galaxy and other galaxies are constantly in motion and interact. Astronomers have found that the Milky Way has swallowed up its neighbors on several occasions. Similar processes are expected in the future. Over time, it will include the Magellanic Cloud and a number of dwarf systems. The most impressive event is expected in 3-5 billion years. This will be a collision with the only neighbor that is visible from Earth with the naked eye. As a result, the Milky Way will become an elliptical galaxy.
The endless expanses of space amaze the imagination. It is difficult for an average person to comprehend the scale of not only the Milky Way or the entire Universe, but even the Earth. However, thanks to the advances in science, we can imagine, at least approximately, which grandiose world we are part of.
Sombrero Galaxy
The Sombrero Galaxy, or spiral galaxy M104, is known for its wide ring of absorbing dust and its hat-like appearance. The galaxy is represented in today's unique picture by images from three large space telescopes in different ranges of the electromagnetic spectrum. The Chandra Observatory's blue high-energy X-ray image indicates the presence of a rarefied hot gas that permeates throughout the galaxy, up to 60,000 light-years from the center. The green optical image of the space telescope. Hubble can see the most familiar glow of the Sombrero stars. Among the stellar populations of the galaxy, the circumnuclear bulge stands out, which we see almost edge-on. A broad band of dust that absorbs light in all other spectral ranges glows in infrared light in the yellow image of the Spitzer telescope. The Sombrero Galaxy is 28 million light-years distant from us and is located on the southern edge of the extended cluster of galaxies in Virgo.
Galaxy "Black Eye"
This spiral galaxy in the catalog is referred to as M64, but it has more romantic names - "Black Eye" and "Sleeping Beauty". If you look at this picture, it is not difficult to see the eye on it, but it is not black.
Now this galaxy is going through a period of very rapid formation of new stars. Astronomers argue that clear signs of this are visible in this not very detailed image: the stars and gas in the outer part of the galaxy are twisting in the opposite direction in relation to the matter located closer to the center. The border between these areas looks like a brighter ellipse, and numerous new stars are born there.
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2MASX J00482185-2507365 eclipsing pair
A pair of overlapping spiral galaxies in the vicinity of NGC 253, sculpted by the Galaxy. Both galaxies are more distant than NGC 253, with the background galaxy, 2MASX J00482185-2507365, lying at redshift z = 0.06, and the plan lay between the galaxy NGC 253 and the reference galaxy (0.0008
This pair of galaxies illuminates the distributions of galactic dust outside the visible weapon as a spiral galaxy. The unexpected scale of dust beyond the stellar limits of the weapon is now showing new directions for extragalactic astronomical research. The dusty weapons extend 6 times the radii of the stellar weapons in the galaxy, and it is also shown silhouetted in the CTH images in relation to the central and main sections of the galactic background.
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Whirlpool Galaxy
This is a snapshot of the Whirlpool galaxy, which might be called a classic spiral galaxy. Her sleeves, studded with young bright stars, are very clear. Whirlpool is a very beautiful galaxy, which is why astronomers (and especially amateur astronomers) love to photograph it. This picture was taken by amateur astronomers Glen and Joan Saurdiff, who were allowed to work on a large professional telescope at Kitt Peak Observatory in Arizona (there is such an incentive program for amateur astronomers).
The Whirlpool Galaxy is located in the constellation Canis Hounds, 31 million light years from Earth. It has two official names in the catalogs: M51 and NGC 5194. To the right of the Whirlpool is a small galaxy NGC 5195, its neighbor (they are also adjacent by catalog numbers). According to astronomers, NGC 5195 has been sliding along the edge of the Maelstrom for several hundred million years. We also note that a supernova exploded in the Whirlpool galaxy last year (more precisely, last year the light of this explosion reached us), and astronomers managed to record this process. Then the Hubble space telescope was also involved in the observations.
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Spiral galaxy
A galaxy whose main observable element is a rotating disk with spiral arms prominent on it. These galaxies include our Galaxy and the nearest large galaxies - the Andromeda Nebula (M31) and the Triangle Nebula (M33)
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Supernova 1987A
Massive stars evolve quite differently. In the central regions of the star at high temperatures, reactions of direct fusion of heavy nuclei take place, after which a spectacular supernova explosion occurs.
Reactions in hot stars. Supernova explosions are one of the most powerful catastrophic natural processes. A fantastic release of energy - as much as the sun generates over billions of years - accompanies a supernova explosion. A supernova can emit more radiation than all the stars in the galaxy combined. Supernovae are stars that explode and reach the maximum absolute magnitude from –11m to –18m. The dense core collapses, dragging the outer layers of the star into free fall towards the center. When the nucleus is strongly compacted, its compression stops, and an oncoming shock wave falls on the upper layers, and the energy of a huge number of neutrinos is splashed out. As a result, the shell scatters at a speed of 10,000 km / s, exposing a neutron star or black hole. In a supernova explosion, an energy of 1046 J. is released. According to the nature of the spectrum near the epoch of maximum, two types of supernovae are distinguished. Type I supernovae near the maximum have a continuous spectrum with no visible lines. Later, strongly broadened absorption lines appear in the spectrum.
This image shows the entire region around the supernova. The most striking feature in the image is the ring with dozens of bright spots.
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Galaxy NGC 1512
Actually, the galaxy NGC 1512 belongs to the class of barred spiral galaxies. The core of such a galaxy has the shape of a bar, from which spiral arms extend. But in the upper image of the central region, the bar is practically invisible, since its luminosity is many times weaker than that of the stellar ring. A general view of the galaxy is shown on the right. Central rings, where new stars form in galaxies, are fairly common in the universe. Astronomers believe that the giant bar, which is the core of such galaxies, "sucks" interstellar gas into the ring. From it, numerous star clusters are formed, which look so spectacular in the upper image.
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Galaxy NGC 3370
It is spiral galaxy NGC 3370, located 98 million light-years from Earth in the constellation Leo. This image was taken recently with the Hubble Space Telescope. It is remarkable not only for its pronounced spiral arms with bright blue regions where new stars are formed. In November 1994, a supernova explosion was noticed in it (however, it should be taken into account that the light of this explosion went up to the Earth for 98 million years, so in fact there is in place, everything has long "calmed down").
This explosion was very effective: it briefly illuminated all the other tens of billions of stars in this galaxy. This explosion was named SN 1994ae in the catalog. It was one of the closest and most well-observed supernova explosions since the introduction of modern digital detectors into the arsenal of astronomers.
Astronomers have classified this explosion as Type Ia. It is this type of supernova explosion that is used to determine the true size and rate of expansion of the universe.
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Galaxy M81
The large and beautiful spiral galaxy M81 in the northern constellation Ursa Major is one of the brightest galaxies visible in the sky from planet Earth. In this remarkable and highly detailed image, we see a bright core, majestic spiral arms and distinct trails of cosmic dust. The structure of the galaxy is similar in scale to the Milky Way. A large streak of dust runs right across the disk, below and to the right of the galactic center, testifying to the galaxy's chaotic past. Other images of M81, which also show the galaxy's spiral structure, show no such detail. This dust lane may be due to the close interaction of the galaxy M81 with its smaller galaxy neighbor, M82. A careful study of variable stars in M81 (NGC 3031) has made it possible to very accurately determine the distance to this galaxy - 11.8 million light years.
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Hog's object
Is this one galaxy or two? This question arose in 1950 when astronomer Art Hoag accidentally discovered this unusual extragalactic object. On the outside is a ring dominated by bright blue stars, and in the center is a ball of redder stars that are likely much older. Between them is a gap that looks almost completely dark. How Hoag's object was formed remains unknown, although several similar objects have now been discovered, which are considered to be one of the forms of ring-shaped galaxies. Origin hypotheses include a collision of galaxies billions of years ago and a disturbing gravitational interaction involving an unusually shaped nucleus. Taken by the Hubble Space Telescope in July 2001, this photograph shows previously unobserved details of the Hoag object and may help to better understand its structure. Hoag's object has a diameter of about 100,000 light years and lies about 600 million light years away in the constellation Serpent. By coincidence, in the gap between the core and the ring (at the point corresponding to one o'clock on the dial), another ring-shaped galaxy is visible, which is much further away.
Based on materials:
http://www.astronet.ru
http://space.com
Galaxies are huge rotating cities of stars. There are at least 100 billion galaxies in the Universe, separated by unimaginable distances of practically empty space. Without a telescope, only three galaxies and part of our own Milky Way Galaxy can be observed from Earth. Two of them are called the Magellanic Clouds.
They received this name in honor of the Portuguese navigator Fernand Magellan. When Magellan's ships sailed in the southern seas in 1519, the crew saw two dimly glowing galaxies in the sky. They brought the news of this with them to Europe.
Closest galaxies to Earth
Magellanic Clouds Galaxy
The Magellanic Clouds really look like two small clouds - faint and solid. These two small galaxies orbit the larger Milky Way. So the Magellanic Clouds are our closest neighbor. How small are these galaxies? One of them contains 15 billion suns, the other only about 5 billion. For comparison, we can say that there are about 200 billion stars in our Galaxy.
Related materials:
Other planets and planetary systems
Andromeda Nebula Galaxy The third galaxy that can be observed with the naked eye is the Andromeda Nebula. It is a spiral galaxy similar to the Milky Way. The Andromeda Nebula is located at a distance of 2.2 million light years from us. A light year is the distance that light travels in one year, traveling 300,000 kilometers per second. It turns out about 9.6 trillion kilometers per year.
