Planets of other solar systems. The solar system is the world in which we live. Barred galaxies
In which the solar system and planet Earth are located. It has the shape of a barred spiral, several arms extend from the center, and all the stars in the Galaxy revolve around its core. Our Sun is located almost on the very outskirts and makes a full revolution every 200 million years. It forms the planetary system most known to mankind, called the Solar system. It consists of eight planets and many other space objects that formed from a cloud of gas and dust about four and a half billion years ago. The solar system is relatively well studied, but stars and other objects beyond it are located at enormous distances, despite belonging to the same Galaxy.
All the stars that humans can observe with the naked eye from Earth are in the Milky Way. The galaxy under this name should not be confused with a phenomenon that appears in the night sky: a bright white stripe crossing the sky. This is part of our Galaxy, a large cluster of stars that looks this way because the Earth is located next to its plane of symmetry.
Planetary systems in the Galaxy
Only one planetary system is called Solar - the one in which the Earth is located. But there are many more systems in our Galaxy, only a small part of which has been discovered. Until 1980, the existence of systems similar to ours was only hypothetical: observation methods did not allow us to detect such relatively small and dim objects. The first assumption about their existence was made by astronomer Jacob from the Madras Observatory in 1855. Finally, in 1988, the first planet outside the solar system was found - it belonged to the orange giant Gamma Cephei A. Then other discoveries followed, it became clear that there could be many of them. Such planets that do not belong to our system are called exoplanets.
Today, astronomers know more than a thousand planetary systems, about half of which have more than one exoplanet. But there are still many candidates for this title who cannot yet confirm this data. Scientists suggest that there are about one hundred billion exoplanets in our Galaxy, which belong to several tens of billions of systems. Perhaps about 35% of all sun-like stars in the Milky Way are not alone.
Some planetary systems found are completely different from the Solar system, others are more similar. In some there are only gas giants (for now there is more information about them, since they are easier to detect), in others there are planets similar to the Earth.
Related article
A galaxy is a system of stars, dust, gas and dark matter held together by gravitational forces. Behind such a prosaic description lies the beauty of millions of shining stars. Some galaxies are named after the constellations in which they are located, and some have beautiful, unique names.
Instructions
Galaxies are named after the greats, discoverers and other outstanding figures and artists (for example, the Magellanic clouds). You might name a galaxy after your mentor, who gave you an important start in life, and you would like to express your gratitude to him in this way. Or you can name the galaxy after the traveler whose adventures you read as a child and whom you still admire.
If you have a loved one, name the galaxy after him. Now, when asked “give me a star,” you can always answer: “I’m giving you a whole galaxy!”, and your lover will be very pleased. In addition, some entomological scientists name discovered insect species after their wives, and they are happy that their husbands decide to perpetuate their names in this way.
Give the galaxy the name of an ancient Greek goddess. The pantheon of goddesses was quite large, and every reader of ancient Greek myths has a favorite character from these legends. The splendor and scale of the galaxy will be well suited to the name of a proud, beautiful and powerful goddess.
You can always name the galaxy after its discoverer, that is, yours. At the same time, you will become widely known throughout the world. Thousands of schoolchildren will also be grateful to you when in astronomy lessons they are asked “who discovered the Ivanova galaxy?”
Video on the topic
Useful advice
Call it what you hold dear. Let the whole world be outraged by the absurdity of your choice. If you are eligible to register the name of a new galaxy, they will have to accept it. So you can call your galaxy either Hair of Veronica or spaghetti with cheese.
There are more than 100 billion stars in our Galaxy; according to the spectral classification, they are classified into one type or another. Stars are divided into spectral classes - O, B, A, F, G, K, M, each of them is characterized by a certain temperature, as well as true and visible colors.
Instructions
There are stars that do not fall into any of the spectral classes; they are called peculiar. They are often normal stars at a certain evolutionary stage. Stars with peculiar spectra have different features of their chemical composition that enhance or weaken the spectral lines of a number of elements. Such stars may not be typical for the immediate vicinity of the Sun, for example, metal-poor stars of globular clusters or galactic haloes.
Most stars belong to the main sequence, they are called normal, such stars include the Sun. Depending on what stage of evolutionary development a star is at, it is classified as a normal star, dwarf or giant star.
A star can be a red giant at the time of formation, as well as in the later stages of its development. At the earliest stage of development, the star radiates due to the gravitational energy that is released during its development. This continues until a thermonuclear reaction begins. After burning out hydrogen, stars converge toward the main sequence, moving into the region of red giants and supergiants.
The total number of exoplanets in the Milky Way galaxy is more than 100 billion. An exoplanet is a planet that is outside our solar system. Currently, scientists have discovered only a small fraction of them. About the 10 most incredible planets in this post.
The darkest exoplanet is the distant, Jupiter-sized gas giant TrES-2b.
Measurements have shown that planet TrES-2b reflects less than one percent of light, making it blacker than coal and naturally darker than any planet in the solar system. The work on this planet was published in the journal of the Royal Astronomical Society Monthly Notices. Planet TrES-2b reflects less light even than black acrylic paint, so it is truly a dark world.
TrES-4
The largest planet found in the Universe is TrES-4. It was discovered in 2006 and is located in the constellation Hercules. The planet, called TrES-4, orbits a star that is about 1,400 light-years away from planet Earth.
Researchers claim that the diameter of the discovered planet is almost 2 times (more precisely 1.7) larger than the diameter of Jupiter (this is the largest planet in the solar system). The temperature of TrES-4 is about 1260 degrees Celsius.
COROT-7b
A year on COROT-7b lasts just over 20 hours. It is not surprising that the weather in this world is, to put it mildly, exotic.
Astronomers have suggested that the planet consists of cast and solid rock, and not of frozen gases, which will certainly boil away under such conditions. The temperature, according to scientists, drops from +2000 C on the illuminated surface to -200 C on the night.
WASP-12b
Astronomers saw a cosmic cataclysm: a star was consuming its own planet, which was in close proximity to it. We are talking about the exoplanet WASP-12b. It was discovered in 2008.
WASP-12b, like most known exoplanets discovered by astronomers, is a large gaseous world. However, unlike most other exoplanets, WASP-12b orbits its star at a very close distance - just over 1.5 million kilometers (75 times closer than Earth to the Sun).
The vast world of WASP-12b has already stared into the face of its death, researchers say. The most important problem of the planet is its size. It has grown to such an extent that it cannot hold its matter against the gravitational forces of its native star. WASP-12b is giving up its matter to the star at a tremendous rate: six billion tons every second. In this case, the planet will be completely destroyed by the star in about ten million years. By cosmic standards, this is quite a bit.
Kepler-10b
Using a space telescope, astronomers were able to discover the smallest rocky exoplanet, with a diameter of about 1.4 times the diameter of Earth.
The new planet was designated Kepler-10b. The star it orbits is about 560 light-years from Earth in the constellation Draco and is similar to our Sun. Belonging to the class of “super-Earths,” Kepler-10b is in an orbit quite close to its star, orbiting it in just 0.84 Earth days, while the temperature on it reaches several thousand degrees Celsius. Scientists estimate that with a diameter of 1.4 times the diameter of the Earth, Kepler-10b has a mass of 4.5 times the Earth's.
HD 189733b
HD 189733b is a Jupiter-sized planet orbiting its star 63 light-years away. And although this planet is similar in size to Jupiter, due to its proximity to its star, it is significantly hotter than the dominant gas giant of our solar system. As with other hot Jupiters found, the rotation of this planet is synchronized with its orbital motion - the planet always faces the star with one side. The orbital period is 2.2 Earth days.
Kepler-16b
Analysis of data on the Kepler-16 system showed that the exoplanet Kepler-16b, discovered in it in June 2011, orbits two stars at once. If an observer could find himself on the surface of the planet, he would see two suns rising and setting, just like on the planet Tatooine from the fantastic Star Wars saga.
In June 2011, scientists announced that the system contained a planet, which they designated Kepler-16b. After conducting a further detailed study, they found that Kepler-16b revolves around a binary star system in an orbit approximately equal to the orbit of Venus, and completes one revolution every 229 days.
Thanks to the joint efforts of amateur astronomers participating in the Planet Hunters project and professional astronomers, a planet was discovered in a four-star system. The planet orbits two stars, which in turn orbit two more stars.
PSR 1257 b and PSR 1257 c
2 planets orbit a dying star.
Kepler-36b and Kepler-36c
Exoplanets Kepler-36b and Kepler-36c - these new planets were discovered by the Kepler telescope. These unusual exoplanets are strikingly close to each other.
Astronomers have discovered a pair of neighboring explanets with different densities orbiting very close to each other. Exoplanets are too close to their star and are not in the so-called "habitable zone" of the star system, that is, the zone where liquid water can exist on the surface, but that is not what makes them interesting. Astronomers were surprised by the very close proximity of these two completely different planets: the orbits of the planets are as close as any other orbits of previously discovered planets.
The universe is huge and fascinating. It is difficult to imagine how small the Earth is compared to the cosmic abyss. Astronomers' best guess is that there are 100 billion galaxies, and the Milky Way is just one of them. As for Earth, there are 17 billion similar planets in the Milky Way alone... and that's 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 ones.
1. Messier 82
Messier 82 or simply M82 is a galaxy five times brighter than the Milky Way. This is due to the very rapid 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 flaming hydrogen that is being ejected from the center of M82.
2. Sunflower Galaxy
Formally known as Messier 63, this galaxy has been nicknamed the Sunflower because it looks like it came straight out of a Vincent van Gogh painting. Its bright, sinuous "petals" are composed of newly formed blue-white giant stars.
3. MACS J0717
MACS J0717 is one of the strangest galaxies known to scientists. Technically, this is not a single stellar object, but a cluster of galaxies - MACS J0717 was 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
If Santa Claus had a favorite galaxy, it would clearly be Messier 74. Astronomers often think about it during the Christmas holidays, because the galaxy is very similar to the Advent wreath.
5. Galaxy Baby Boom
Located approximately 12.2 billion light-years from Earth, the Baby Boom Galaxy was discovered in 2008. It got its nickname due to the fact that new stars are born in it incredibly quickly - approximately every 2 hours. For example, in the Milky Way, a new star appears on average every 36 days.
6. Milky Way
Our Milky Way Galaxy (which contains the Solar System and, by extension, the Earth) is truly 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
Thanks to the IDCS 1426 galaxy cluster, today we can see what the Universe was like two-thirds younger than it is now. IDCS 1426 is the most massive galaxy cluster in the early Universe, having a mass of about 500 trillion Suns. The galaxy's bright blue core of gas is the result of the collision of galaxies in this cluster.
8.I Zwicky 18
The blue dwarf galaxy I Zwicky 18 is the youngest known galaxy. Its age is only 500 million years (the age of the Milky Way is 12 billion years) and it is essentially in an embryonic state. This is a giant cloud of cold hydrogen and helium.
9. NGC 6744
NGC 6744 is a large spiral galaxy that astronomers believe is one of the most similar to our Milky Way. The galaxy, located about 30 million light-years from Earth, has a remarkably similar elongated core and spiral arms 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 NGC 6872 has virtually no free hydrogen left to form stars, it is sucking it out of the neighboring galaxy IC 4970.
11. MACS J0416
Found 4.3 billion light-years from Earth, galaxy MACS J0416 looks more like some kind of light show at a fancy disco. In fact, behind the bright purple and pink colors lies an event of colossal proportions - the collision of two galaxy clusters.
12. M60 and NGC 4647 - galactic pair
Although gravitational forces pull most galaxies towards each other, there is no evidence that this is happening with neighboring Messier 60 and NGC 4647, nor is there any evidence that they are moving away from each other. Like a couple living together long ago, these two galaxies race side by side through cold, dark space.
13. Messier 81
Located near Messier 25, Messier 81 is a spiral galaxy with a supermassive black hole at its center that is 70 million times the mass of the Sun. M81 is home to many short-lived but very hot blue stars. Gravitational interaction with M82 resulted in plumes of hydrogen gas stretching between both galaxies.
About 600 million years ago, the galaxies NGC 4038 and NGC 4039 crashed into each other, beginning a massive exchange of stars and galactic matter. Because of their appearance, these galaxies are called antennas.
15. Galaxy Sombrero
The Sombrero Galaxy is one of the most popular among amateur astronomers. It gets its name because it looks like this headdress thanks to its bright core and large central bulge.
16. 2MASX J16270254 + 4328340
This galaxy, blurry in all photographs, is known under the rather complex name 2MASX J16270254 + 4328340. As a result of the merger of two galaxies, a “fine fog consisting of millions of stars” was formed. This "fog" is believed to be slowly dissipating as the galaxy reaches the end of its lifespan.
17. NGC 5793
Not too strange (though very pretty) at first glance, spiral galaxy NGC 5793 is better known for a rare phenomenon: masers. People are familiar with lasers, which emit light in the visible region of the spectrum, but few know about masers, which emit light in the microwave range.
18. Triangulum Galaxy
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, also sometimes called a spiral galaxy, is located in the constellation Ursa Major. As one of the first polar ring galaxies found, NGC 2685 has an outer ring of gas and stars orbiting the galaxy's poles, making it one of the rarest types of galaxies. Scientists still don't know what causes these polar rings to form.
20. Messier 94
Messier 94 looks like a terrible hurricane that was removed from orbit on Earth. This galaxy is surrounded by bright blue rings of actively forming stars.
21. Pandora Cluster
Formally known as Abell 2744, this galaxy has been nicknamed the Pandora cluster due to a number of strange phenomena resulting from the collision of several smaller clusters of galaxies. There is real chaos going on inside.
22. NGC 5408
What looks more like a colorful birthday cake in the photos is an irregular galaxy in the constellation Centaurus. It is notable for the fact that it emits extremely powerful X-rays.
23. 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 spiral galaxy to be classified and is of particular interest to scientists due to its interaction with the dwarf galaxy NGC 5195.
24.SDSS J1038+4849
The galaxy cluster SDSS J1038+4849 is one of the most attractive clusters ever found by astronomers. He looks like a real smiley face in space. The eyes and nose are galaxies, and the curved line of the "mouth" is due to the effects of gravitational lensing.
25. NGC3314a and NGC3314b
Although these two galaxies look like they are colliding, this is actually an optical illusion. There are tens of millions of light years between them.
Surely, many of you have seen a gif or watched a video showing the movement of the solar system.
Video clip, released in 2012, went viral and created a lot of buzz. I came across it shortly after its appearance, when I knew much less about space than I do now. And what confused me most of all was the perpendicularity of the plane of the planets’ orbits to the direction of motion. Not that it is impossible, but the solar system can move at any angle to the galactic plane. You may ask, why remember long-forgotten stories? The fact is that right now, if desired and in good weather, everyone can see in the sky the real angle between the planes of the ecliptic and the Galaxy.
Checking the scientists
Astronomy says that the angle between the planes of the ecliptic and the Galaxy is 63°.
But the figure itself is boring, and even now, when flat Earth adherents are organizing a coven on the sidelines of science, I would like to have a simple and clear illustration. Let's think about how we can see the planes of the Galaxy and the ecliptic in the sky, preferably with the naked eye and without moving too far from the city? The plane of the Galaxy is the Milky Way, but now, with the abundance of light pollution, it is not so easy to see. Is there some line approximately close to the plane of the Galaxy? Yes - this is the constellation Cygnus. It is clearly visible even in the city, and it is easy to find it based on the bright stars: Deneb (alpha Cygnus), Vega (alpha Lyrae) and Altair (alpha Eagle). The “torso” of Cygnus roughly coincides with the galactic plane.
Okay, we have one plane. But how to get a visual ecliptic line? Let's think about what the ecliptic actually is? According to the modern strict definition, the ecliptic is a section of the celestial sphere by the orbital plane of the barycenter (center of mass) of the Earth-Moon. On average, the Sun moves along the ecliptic, but we do not have two Suns along which it is convenient to draw a line, and the constellation Cygnus will not be visible in sunlight. But if we remember that the planets of the solar system also move in approximately the same plane, then it turns out that the parade of planets will approximately show us the plane of the ecliptic. And now in the morning sky you can just see Mars, Jupiter and Saturn.
As a result, in the coming weeks in the morning before sunrise it will be possible to very clearly see the following picture:
Which, surprisingly, agrees perfectly with astronomy textbooks.
It’s more correct to draw a gif like this:
Source: astronomer Rhys Taylor website rhysy.net
The question may be about the relative position of the planes. Are we flying?<-/ или же <-\ (если смотреть с внешней стороны Галактики, северный полюс вверху)? Астрономия говорит, что Солнечная система движется относительно ближайших звезд в направлении созвездия Геркулеса, в точку, расположенную недалеко от Веги и Альбирео (бета Лебедя), то есть правильное положение <-/.
But this fact, alas, cannot be verified by hand, because even though they did it two hundred and thirty-five years ago, they used the results of many years of astronomical observations and mathematics.
Scattering stars
How can one even determine where the solar system is moving relative to nearby stars? If we can record the movement of a star across the celestial sphere for decades, then the direction of movement of several stars will tell us where we are moving relative to them. Let's call the point to which we are moving the apex. Stars that are close to it, as well as from the opposite point (antiapex), will move weakly because they are flying towards us or away from us. And the farther the star is from the apex and antiapex, the greater its own motion will be. Imagine that you are driving along the road. Traffic lights at intersections ahead and behind will not move too much to the sides. But the lampposts along the road will still flicker (have a lot of their own movement) outside the window.
The gif shows the movement of Barnard's star, which has the largest proper motion. Already in the 18th century, astronomers had records of the positions of stars over an interval of 40-50 years, which made it possible to determine the direction of movement of slower stars. Then the English astronomer William Herschel took star catalogs and, without going to the telescope, began to calculate. Already the first calculations using the Mayer catalog showed that the stars do not move chaotically, and the apex can be determined.
Source: Hoskin, M. Herschel's Determination of the Solar Apex, Journal for the History of Astronomy, Vol. 11, P. 153, 1980
And with the data from the Lalande catalogue, the area was significantly reduced.
From there
Next came the normal scientific work - clarification of data, calculations, disputes, but Herschel used the correct principle and was mistaken by only ten degrees. Information is still being collected, for example, just thirty years ago the speed of movement was reduced from 20 to 13 km/s. Important: this speed should not be confused with the speed of the solar system and other nearby stars relative to the center of the Galaxy, which is approximately 220 km/s.
Even further
Well, since we mentioned the speed of movement relative to the center of the Galaxy, we need to figure it out here too. The galactic north pole was chosen in the same way as the earth's - arbitrarily by convention. It is located near the star Arcturus (alpha Boötes), approximately up the wing of the constellation Cygnus. In general, the projection of constellations on the Galaxy map looks like this:
Those. The solar system moves relative to the center of the Galaxy in the direction of the constellation Cygnus, and relative to local stars in the direction of the constellation Hercules, at an angle of 63° to the galactic plane,<-/, если смотреть с внешней стороны Галактики, северный полюс сверху.
Space tail
But the comparison of the solar system with a comet in the video is completely correct. NASA's IBEX apparatus was specially created to determine the interaction between the boundary of the solar system and interstellar space. And according to himThose who have a little idea about the Universe are well aware that the cosmos is constantly in motion. The universe is expanding every second, becoming larger and larger. Another thing is that on the scale of human perception of the world, it is quite difficult to understand the size of what is happening and imagine the structure of the Universe. In addition to our galaxy, in which the Sun is located and we are located, there are dozens, hundreds of other galaxies. Nobody knows the exact number of distant worlds. How many galaxies are in the Universe can only be known approximately by creating a mathematical model of the cosmos.
Therefore, given the size of the Universe, we can easily assume that tens, hundreds of billions of light years from Earth, there are worlds similar to ours.
Space and worlds that surround us
Our galaxy, which received the beautiful name “Milky Way,” was, according to many scientists, the center of the universe just a few centuries ago. In fact, it turned out that this is only part of the Universe, and there are other galaxies of various types and sizes, large and small, some further, others closer.
In space, all objects are closely interconnected, move in a certain order and occupy an allotted place. The planets we know, the stars we know, black holes, and our solar system itself are located in the Milky Way galaxy. The name is not accidental. Even ancient astronomers, observing the night sky, compared the space around us to a milk track, where thousands of stars look like drops of milk. The Milky Way Galaxy, the celestial galactic objects in our field of vision, make up the nearby cosmos. What may be beyond the visibility of telescopes became known only in the 20th century.
Subsequent discoveries, which expanded our cosmos to the size of the Metagalaxy, led scientists to the theory of the Big Bang. A grandiose cataclysm occurred almost 15 billion years ago and served as an impetus for the beginning of the processes of formation of the Universe. One stage of the substance was replaced by another. From dense clouds of hydrogen and helium, the first beginnings of the Universe began to form - protogalaxies consisting of stars. All this happened in the distant past. The light of many celestial bodies, which we can observe in the strongest telescopes, is only a farewell greeting. Millions of stars, if not billions, dotted our sky, located a billion light years from Earth, and have long ceased to exist.
Map of the Universe: nearest and farthest neighbors
Our Solar System and other cosmic bodies observed from Earth are relatively young structural formations and our closest neighbors in the vast Universe. For a long time, scientists believed that the dwarf galaxy closest to the Milky Way was the Large Magellanic Cloud, located only 50 kiloparsecs. Only very recently have the real neighbors of our galaxy become known. In the constellation Sagittarius and in the constellation Canis Major there are small dwarf galaxies whose mass is 200-300 times less than the mass of the Milky Way, and the distance to them is just over 30-40 thousand light years.
These are one of the smallest universal objects. In such galaxies the number of stars is relatively small (on the order of several billion). As a rule, dwarf galaxies gradually merge or are absorbed by larger formations. The speed of the expanding Universe, which is 20-25 km/s, will unwittingly lead neighboring galaxies to a collision. When this will happen and how it will turn out, we can only guess. The collision of galaxies is happening all this time, and due to the transience of our existence, it is not possible to observe what is happening.
Andromeda, two to three times the size of our galaxy, is one of the closest galaxies to us. It continues to be one of the most popular among astronomers and astrophysicists and is located just 2.52 million light years from Earth. Like our galaxy, Andromeda is a member of the Local Group of galaxies. The size of this giant cosmic stadium is three million light years across, and the number of galaxies present in it is about 500. However, even such a giant as Andromeda looks short in comparison with the galaxy IC 1101.
This largest spiral galaxy in the Universe is located more than a hundred million light years away and has a diameter of more than 6 million light years. Despite containing 100 trillion stars, the galaxy is primarily composed of dark matter.
Astrophysical parameters and types of galaxies
The first space explorations carried out at the beginning of the 20th century provided plenty of food for thought. The cosmic nebulae discovered through the lens of a telescope, of which more than a thousand were eventually counted, were the most interesting objects in the Universe. For a long time, these bright spots in the night sky were considered to be gas accumulations that were part of the structure of our galaxy. Edwin Hubble in 1924 managed to measure the distance to a cluster of stars and nebulae and made a sensational discovery: these nebulae are nothing more than distant spiral galaxies, independently wandering across the scale of the Universe.
An American astronomer was the first to suggest that our Universe is made up of many galaxies. Space exploration in the last quarter of the 20th century, observations made using spacecraft and technology, including the famous Hubble telescope, confirmed these assumptions. Space is limitless and our Milky Way is far from the largest galaxy in the Universe and, moreover, is not its center.
Only with the advent of powerful technical means of observation, the Universe began to take on clear outlines. Scientists are faced with the fact that even such huge formations as galaxies can differ in their structure and structure, shape and size.
Through the efforts of Edwin Hubble, the world received a systematic classification of galaxies, dividing them into three types:
- spiral;
- elliptical;
- incorrect.
Elliptical and spiral galaxies are the most common types. These include our Milky Way galaxy, as well as our neighboring Andromeda galaxy and many other galaxies in the Universe.
Elliptical galaxies have the shape of an ellipse and are elongated in one direction. These objects lack sleeves and often change their shape. These objects also differ from each other in size. Unlike spiral galaxies, these cosmic monsters do not have a clearly defined center. There is no core in such structures.
According to the classification, such galaxies are designated by the Latin letter E. All currently known elliptical galaxies are divided into subgroups E0-E7. The distribution into subgroups is carried out depending on the configuration: from almost circular galaxies (E0, E1 and E2) to highly elongated objects with indices E6 and E7. Among the elliptical galaxies there are dwarfs and true giants with diameters of millions of light years.
There are two subtypes of spiral galaxies:
- galaxies presented in the form of a crossed spiral;
- normal spirals.
The first subtype is distinguished by the following features. In shape, such galaxies resemble a regular spiral, but in the center of such a spiral galaxy there is a bridge (bar), giving rise to arms. Such bridges in a galaxy are usually a consequence of physical centrifugal processes that divide the galactic core into two parts. There are galaxies with two nuclei, the tandem of which makes up the central disk. When the nuclei meet, the bridge disappears and the galaxy becomes normal, with one center. There is also a bridge in our Milky Way galaxy, in one of the arms of which our Solar system is located. From the Sun to the center of the galaxy, the path, according to modern estimates, is 27 thousand light years. The thickness of the Orion Cygnus arm, in which our Sun and our planet reside, is 700 thousand light years.
In accordance with the classification, spiral galaxies are designated by the Latin letters Sb. Depending on the subgroup, there are other designations for spiral galaxies: Dba, Sba and Sbc. The difference between the subgroups is determined by the length of the bar, its shape and the configuration of the sleeves.
Spiral galaxies can range in size from 20,000 light-years to 100,000 light-years in diameter. Our Milky Way galaxy is in the “golden mean”, its size gravitating toward medium-sized galaxies.
The rarest type is irregular galaxies. These universal objects are large clusters of stars and nebulae that do not have a clear shape or structure. In accordance with the classification, they received the indices Im and IO. As a rule, structures of the first type do not have a disk or it is weakly expressed. Often such galaxies can be seen to have similar arms. Galaxies with IO indices are a chaotic collection of stars, clouds of gas and dark matter. Prominent representatives of this group of galaxies are the Large and Small Magellanic Clouds.
All galaxies: regular and irregular, elliptical and spiral, consist of trillions of stars. The space between stars and their planetary systems is filled with dark matter or clouds of cosmic gas and dust particles. In the spaces between these voids there are black holes, large and small, which disturb the idyll of cosmic tranquility.
Based on the existing classification and research results, we can answer with some confidence the question of how many galaxies there are in the Universe and what type they are. There are more spiral galaxies in the Universe. They constitute more than 55% of the total number of all universal objects. There are half as many elliptical galaxies - only 22% of the total number. There are only 5% of irregular galaxies similar to the Large and Small Magellanic Clouds in the Universe. Some galaxies are neighboring us and are in the field of view of the most powerful telescopes. Others are in the farthest space, where dark matter predominates and the blackness of endless space is more visible in the lens.
Galaxies up close
All galaxies belong to certain groups, which in modern science are usually called clusters. The Milky Way is part of one of these clusters, which contains up to 40 more or less known galaxies. The cluster itself is part of a supercluster, a larger group of galaxies. The Earth, along with the Sun and the Milky Way, is part of the Virgo supercluster. This is our actual cosmic address. Together with our galaxy, there are more than two thousand other galaxies in the Virgo cluster, elliptical, spiral and irregular.
The map of the Universe, which astronomers rely on today, gives an idea of what the Universe looks like, what its shape and structure are. All clusters gather around voids or bubbles of dark matter. It is possible that dark matter and bubbles are also filled with some objects. Perhaps this is antimatter, which, contrary to the laws of physics, forms similar structures in a different coordinate system.
Current and future state of galaxies
Scientists believe that it is impossible to create a general portrait of the Universe. We have visual and mathematical data about the cosmos that is within our understanding. The real scale of the Universe is impossible to imagine. What we see through a telescope is starlight that has been coming to us for billions of years. Perhaps the real picture today is completely different. As a result of cosmic cataclysms, the most beautiful galaxies in the Universe could already turn into empty and ugly clouds of cosmic dust and dark matter.
It cannot be ruled out that in the distant future, our galaxy will collide with a larger neighbor in the Universe or swallow a dwarf galaxy existing next door. What the consequences of such universal changes will be remains to be seen. Despite the fact that the convergence of galaxies occurs at the speed of light, earthlings are unlikely to witness a universal catastrophe. Mathematicians have calculated that just over three billion Earth years are left before the fatal collision. Whether life will exist on our planet at that time is a question.
Other forces can also interfere with the existence of stars, clusters and galaxies. Black holes, which are still known to man, are capable of swallowing a star. Where is the guarantee that such monsters of enormous size, hiding in dark matter and in the voids of space, will not be able to swallow the galaxy entirely?
