The closest galaxy to the solar system. Distances to nearby galaxies
Of the large star systems nearby, the Andromeda nebula (M31) is located - a spiral galaxy 2.6 times larger in size than our home - the Milky Way galaxy: its diameter is 260 thousand light years. The Andromeda nebula is located at a distance of 2.5 million light years (772 kiloparsecs) from us, and its mass is 300 billion solar masses. It consists of about a trillion stars (for comparison: the Milky Way contains about 100 billion stars).
The Andromeda nebula is the most distant cosmic object from us that can be observed in the starry sky (northern hemisphere) with the naked eye, even in urban light conditions - it looks like a luminous blurry oval. It should be remembered that due to the fact that the light from the Andromeda galaxy travels to us for 2.5 million years, we see it as it was 2.5 million years ago, and we do not know what it looks like now moment.
B - Andromeda Galaxy in ultraviolet rays
Astronomers have found that the Andromeda Galaxy and our Galaxy are approaching each other at a speed of 100-140 km/s. In about 3-4 billion years, perhaps they will collide and then they will merge into one giant galaxy. We hasten to reassure those who are concerned about the fate of the Solar System as a result of this collision: most likely there will be no impact on the Sun and planets. Galactic merger processes are not accompanied by catastrophic stellar collisions, since the distances between stars are very large compared to the size of the stars themselves.
However, one should not think that the process of merging galaxies, stretched over millions of years, occurs without dramatic effects. When two galaxies approach each other, clouds of interstellar gas come into contact first. Due to the rapid interpenetration, their density increases sharply, they heat up, and the growing pressure turns these gas and dust clouds into centers for the formation of new stars. A violent, explosive process of star formation begins, accompanied by flares, explosions and the ejection of monstrously extended jets of dust and gas.
However, let's return to our neighbors. The second closest spiral galaxy to us is M33. It is located in the constellation Triangulum and is 2.4 million light years away from us. Its diameter is 2 times smaller than the Milky Way and 4 times smaller than the Andromeda Galaxy. It can also be seen with the naked eye, but only on a moonless night and outside the city. It looks like a dim, foggy speck between α Triangulum and τ Pisces.
A - the position of the galaxy in the starry sky
B - Triangulum Galaxy (NASA photo in ultraviolet and visible range)
All other galaxies in our immediate environment are dwarf elliptical and irregular galaxies. Of the irregular galaxies closest to us, two are of greatest interest: Large and Small Magellanic Clouds.
The Magellanic Clouds are satellites of our Milky Way Galaxy. They are also visible to the naked eye, although only in the southern hemisphere. The Large Magellanic Cloud is located in the constellation Doradus. It is 170 thousand light years away from us (50 kiloparsecs), its diameter is 20 thousand light years, and it contains about 30 billion stars. Despite being an irregular galaxy, the Large Magellanic Cloud has a structure similar to that of crossed spiral galaxies. It contains all the types of stars that are known in the Milky Way. Another interesting object was discovered in the Large Magellanic Cloud - one of the brightest known gas and dust complexes with a length of 700 light years - Tarantula Nebula, a hotbed of rapid star formation.
Survey with the TRAPPIST telescope (La Silla Observatory, Chile)
The Small Magellanic Cloud is 3 times smaller than the Large Magellanic Cloud and also resembles a crossed spiral galaxy. It is located in the constellation Tucana, next to Dorado. The distance from us to this galaxy is 210 thousand light years (60 kiloparsecs).
The Magellanic Clouds are surrounded by a common shell of neutral hydrogen, which is called the Magellanic System.
Both Magellanic clouds are victims galactic cannibalism from the side of the Milky Way: the gravitational influence of our Galaxy gradually destroys them and attracts the matter of these galaxies. Hence the irregular shape of the Magellanic Clouds. Experts believe that these are the remains of two small galaxies in the process of gradual disappearance. According to astronomers, in the next 10 billion years the Milky Way will completely absorb all the material of the Magellanic Clouds. Similar processes occur between the Magellanic clouds themselves: due to their gravity, the Large Magellanic Cloud “steals” millions of stars from the Small Magellanic Cloud. Perhaps this fact explains the high star-forming activity in the Tarantula Nebula: this region is exactly in the path of the gas flow that the gravity of the Large Magellanic Cloud pulls from the Small Magellanic Cloud.
Thus, using the example of what is happening in the vicinity of our Galaxy, you can again be convinced that the merger of galaxies and the absorption of small galaxies by larger ones is a completely ordinary phenomenon in galactic life.
Our Galaxy, the Andromeda Galaxy and the Triangulum Galaxy form a group of galaxies connected by gravitational interaction. They call her Local group of galaxies. The size of the Local Group is 1.5 megaparsecs across. In addition to three large spiral galaxies, the Local Group includes more than 50 dwarf and irregular (shaped) galaxies. Thus, the Andromeda Galaxy has at least 19 satellite galaxies, and our Galaxy has 14 known satellites (as of 2005). In addition to them, the Local Group includes other dwarf galaxies that are not satellites of large galaxies.
Astronomy is an amazingly fascinating science that reveals to inquisitive minds all the diversity of the Universe. There are hardly people who, as a child, would never watch the scattering of stars in the night sky. This picture looks especially beautiful in the summer, when the stars seem so close and incredibly bright. In recent years, astronomers around the world have been particularly interested in Andromeda, the galaxy closest to our home Milky Way. We decided to find out what exactly attracts scientists about it and whether it can be seen with the naked eye.
Andromeda: brief description
The Andromeda Galaxy, or simply Andromeda, is one of the largest. It is approximately three to four times larger than our Milky Way, where the Solar System is located. It contains, according to preliminary estimates, about one trillion stars.
Andromeda is a spiral galaxy; it can be seen in the night sky even without special optical devices. But keep in mind that the light from this star cluster takes more than two and a half million years to reach our Earth! Astronomers say we now see the Andromeda Nebula as it was two million years ago. Isn't this a miracle?
The Andromeda Nebula: from the history of observations
Andromeda was first spotted by an astronomer from Persia. He cataloged it in 1946 and described it as a hazy glow. Seven centuries later, the galaxy was described by a German astronomer who observed it over time using a telescope.
In the mid-nineteenth century, astronomers determined that Andromeda's spectrum was significantly different from previously known galaxies, and suggested that it consisted of many stars. This theory was completely justified.
The Andromeda Galaxy, photographed only at the end of the nineteenth century, has a spiral structure. Although at that time it was considered just a large part of the Milky Way.
Structure of the galaxy
With the help of modern telescopes, astronomers were able to analyze the structure of the Andromeda Nebula. The Hubble telescope made it possible to see about four hundred young stars orbiting a black hole. This star cluster is approximately two hundred million years old. This structure of the galaxy quite surprised scientists, because until now they had not even imagined that stars could form around a black hole. According to all previously known laws, the process of condensation of gas before the formation of a star is simply impossible under the conditions of a black hole.
The Andromeda nebula has several satellite dwarf galaxies; they are located on its outskirts and could end up there as a result of absorption. This is doubly interesting due to the fact that astronomers are predicting a collision between the Milky Way and the Andromeda Galaxy. True, this phenomenal event will not happen soon.
The Andromeda Galaxy and the Milky Way: moving towards each other
Scientists have been making certain predictions for quite some time, observing the movement of both stellar systems. The fact is that Andromeda is a galaxy that is constantly moving towards the Sun. At the beginning of the twentieth century, an American astronomer was able to calculate the speed at which this movement occurs. This figure, three hundred kilometers per second, is still used by all astronomers around the world in their observations and calculations.
However, their calculations differ significantly. Some scientists claim that the galaxies will collide only in seven billion years, but others are confident that the speed of Andromeda’s movement is constantly increasing, and a meeting can be expected in four billion years. Scientists do not exclude a scenario in which, in a few decades, this predicted figure will once again decrease significantly. At the moment, it is still generally accepted that a collision should not be expected earlier than four billion years from now. What does Andromeda (galaxy) threaten us with?
Collision: what will happen?
Since the absorption of the Milky Way by Andromeda is inevitable, astronomers are trying to simulate the situation in order to have at least some information about this process. According to computer data, as a result of absorption, the Solar system will be on the outskirts of the galaxy, it will fly over a distance of one hundred and sixty thousand light years. Compared to the current position of our solar system towards the center of the galaxy, it will move away from it by twenty-six thousand light years.
The new future galaxy has already received the name Milkyhoney, and astronomers claim that due to the merger it will be younger by at least one and a half billion years. In this process, new stars will form, which will make our galaxy much brighter and more beautiful. She will also change shape. Now the Andromeda Nebula is at a certain angle to the Milky Way, but during the merger process the resulting system will take on the shape of an ellipse and become more voluminous, so to speak.
The fate of humanity: will we survive the impact?
What will happen to people? How will the meeting of galaxies affect our Earth? Surprisingly, scientists say that there is absolutely no way!!! All changes will be expressed in the appearance of new stars and constellations. The map of the sky will completely change, because we will find ourselves in a completely new and unexplored corner of the galaxy.
Of course, some astronomers leave an extremely insignificant percentage of negative developments. In this scenario, the Earth could collide with the Sun or another stellar body from the Andromeda galaxy.
Are there planets in the Andromeda Nebula?
Scientists regularly search for planets in galaxies. They do not give up attempts to discover in the vastness of the Milky Way a planet similar in characteristics to our Earth. At the moment, more than three hundred objects have already been discovered and described, but all of them are located in our star system. In recent years, astronomers have begun to take an increasingly closer look at Andromeda. Are there any planets there at all?
Thirteen years ago, a group of astronomers, using a new method, hypothesized that one of the stars in the Andromeda Nebula hosts a planet. Its estimated mass is six percent of the largest planet in our solar system - Jupiter. Its mass is three hundred times the mass of the Earth.
At the moment, this assumption is at the testing stage, but has every chance of becoming a sensation. After all, until now astronomers have not discovered planets in other galaxies.
Preparing to search for a galaxy in the sky
As we have already said, even with the naked eye you can see a neighboring galaxy in the night sky. Of course, for this you need to have some knowledge of astronomy (at least know what the constellations look like and be able to find them).
In addition, it is almost impossible to see certain clusters of stars in the night sky of the city - light pollution will prevent observers from seeing at least anything. Therefore, if you still want to see the Andromeda Nebula with your own eyes, then go to the village at the end of summer, or at least to a city park, where there are not many streetlights. The best time for observation is October, but from August to September it is quite clearly visible above the horizon.
Andromeda Nebula: search scheme
Many young amateur astronomers dream of finding out what Andromeda really looks like. The galaxy in the sky resembles a small bright spot, but it can be found thanks to the bright stars that are located nearby.
The easiest way is to find Cassiopeia in the autumn sky - it looks like the letter W, only more elongated than it is usually denoted in writing. Usually the constellation is clearly visible in the Northern Hemisphere and is located in the eastern part of the sky. The Andromeda Galaxy lies below. To see it, you need to find a few more landmarks.
They are three bright stars below Cassiopeia, they are elongated in a line and have a red-orange hue. The middle one, Mirak, is the most accurate reference point for novice astronomers. If you draw a straight line upward from it, you will notice a small luminous spot that resembles a cloud. It is this light that will be the Andromeda galaxy. Moreover, the glow that you can observe was sent to Earth even when there was not a single person on the planet. Amazing fact, isn't it?
Andromeda is a galaxy also popular as M31 and NGC224. This is a spiral formation located at a distance of approximately 780 kp (2.5 million light years) from Earth.
Andromeda is the galaxy closest to the Milky Way. It is named after the mythical princess of the same name. Observations in 2006 led to the conclusion that there are about a trillion stars here - at least twice as many as in the Milky Way, where there are about 200 - 400 billion. Scientists believe that the collision of the Milky Way and the Andromeda galaxy will happen in about 3.75 billion years, and eventually a huge elliptical or disk galaxy will be formed. But more on that later. First, let’s find out what a “mythical princess” looks like.
The picture shows Andromeda. The galaxy has white and blue stripes. They form rings around it and cover the hot, red-hot huge stars. The dark blue-gray bands contrast sharply with these bright rings and show areas where star formation is just beginning in dense cloud cocoons. When observed in the visible part of the spectrum, Andromeda's rings look more like spiral arms. In the ultraviolet spectrum, these formations rather resemble ring structures. They were previously discovered by a NASA telescope. Astrologers believe that these rings indicate the formation of a galaxy as a result of a collision with a neighboring one more than 200 million years ago.
Like the Milky Way, Andromeda has a number of miniature satellites, 14 of which have already been discovered. The most famous are M32 and M110. Of course, it is unlikely that the stars of each galaxy will collide together, since the distances between them are very vast. Scientists still have rather vague ideas about what will happen in reality. But a name has already been invented for the future newborn. Mammoth - this is what scientists call the still unborn huge galaxy.
Star collisions
Andromeda is a galaxy with 1 trillion stars (1012), and the Milky Way has 1 billion (3*1011). However, the chance of a collision between celestial bodies is negligible, since there is a huge distance between them. For example, the closest star to the Sun, Proxima Centauri, is located at a distance of 4.2 light years (4*1013 km), or 30 million (3*107) diameters of the Sun. Imagine that our luminary is a table tennis ball. Then Proxima Centauri will look like a pea, located at a distance of 1100 km from it, and the Milky Way itself will extend 30 million km in width. Even the stars in the center of the galaxy (and specifically there their largest cluster) are located at intervals of 160 billion (1.6 * 1011) km. That's like one table tennis ball for every 3.2 km. Therefore, the chance that any two stars will collide during a galaxy merger is extremely small.
Black hole collision
The Andromeda Galaxy and the Milky Way have central supermassive black holes: Sagittarius A (3.6 * 106 solar masses) and an object inside the P2 cluster of the Galactic Core. These black holes will converge on one point near the center of the newly formed galaxy, transferring orbital energy to the stars, which will eventually move to higher trajectories. The above process can take millions of years. When the black holes come within one light year of each other, they will begin to emit gravitational waves. The orbital energy will become even more powerful until the merger is complete. Based on modeling data carried out in 2006, the Earth may first be thrown almost to the very center of the newly formed galaxy, then pass near one of the black holes and be ejected beyond the boundaries of the Milky Way.
Confirmation of the theory
The Andromeda Galaxy is approaching us at a speed of approximately 110 km per second. Right up until 2012, there was no way to know whether a collision would occur or not. The Hubble Space Telescope helped scientists conclude that it was almost inevitable. After tracking the movements of Andromeda from 2002 to 2010, it was concluded that the collision will occur in about 4 billion years.
Similar phenomena are widespread in space. For example, Andromeda is believed to have interacted with at least one galaxy in the past. And some dwarf galaxies, such as SagDEG, continue to collide with the Milky Way, creating a single formation.
Research also shows that M33, or the Triangulum Galaxy, the third largest and brightest member of the Local Group, will also participate in this event. Its most likely fate will be the entry into orbit of the object formed after the merger, and in the distant future - final unification. However, a collision of M33 with the Milky Way before Andromeda approaches, or our Solar System is thrown beyond the boundaries of the Local Group, is excluded.
Fate of the Solar System
Scientists from Harvard claim that the timing of the galaxy merger will depend on the tangential speed of Andromeda. Based on the calculations, it was concluded that there is a 50% chance that during the merger the Solar System will be thrown back to a distance three times greater than the current one to the center of the Milky Way. It is not clear exactly how the Andromeda galaxy will behave. Planet Earth is also under threat. Scientists say there is a 12% chance that some time after the collision we will be thrown back beyond the borders of our former “home”. But this event will most likely not have major adverse effects on the Solar System, and celestial bodies will not be destroyed.
If we exclude planetary engineering, then by the time the galaxies collide, the surface of the Earth will become very hot and there will be no water left on it in a watery state, and therefore no life.
Possible side effects
When two spiral galaxies merge, the hydrogen present in their disks is compressed. The intensive formation of new stars begins. For example, this can be observed in the interacting galaxy NGC 4039, otherwise known as the Antennae Galaxy. If Andromeda and the Milky Way merge, it is believed that there will be little gas left on their disks. Star formation will not be as intense, although the birth of a quasar is entirely possible.
Merger result
Scientists tentatively call the galaxy formed during the merger Milcomeda. The simulation result shows that the resulting object will have an elliptical shape. Its center will have a lower density of stars than modern elliptical galaxies. But a disk form is also possible. Much will depend on how much gas remains within the Milky Way and Andromeda. In the near future, the remaining galaxies of the Local Group will merge into one object, and this will mark the beginning of a new evolutionary stage.
Facts about Andromeda
Andromeda is the largest Galaxy in the Local Group. But perhaps not the most massive. Scientists suggest that there is more dark matter concentrated in the Milky Way, and this is what makes our galaxy more massive. Scientists will study Andromeda in order to understand the origin and evolution of formations similar to it, because it is the closest spiral galaxy to us. Andromeda looks amazing from Earth. Many even manage to photograph her. Andromeda has a very dense galactic core. Not only are huge stars located at its center, but there is also at least one supermassive black hole hidden at its core. Its spiral arms were bent as a result of gravitational interaction with two neighboring galaxies: M32 and M110. There are at least 450 globular star clusters orbiting inside Andromeda. Among them are some of the densest that have been discovered. The Andromeda Galaxy is the most distant object that can be seen with the naked eye. You'll need a good vantage point and minimal bright light.
In conclusion, I would like to advise readers to raise their gaze to the starry sky more often. It stores a lot of new and unknown things. Find some free time to observe space on the weekend. The Andromeda Galaxy in the sky is a sight to behold.
Scientists have known for some time that the Milky Way Galaxy is not the only one in the Universe. In addition to our galaxy, which is part of the Local Group - a collection of 54 galaxies and dwarf galaxies - we are also part of a larger formation, also known as the Virgo Cluster of Galaxies. So, we can say that the Milky Way has many neighbors.
Of these, most people believe that the Andromeda Galaxy is our closest galactic neighbor. But in truth, Andromeda is the closest spiral Galaxy, but not the nearest Galaxy at all. This distinction falls to the formation of what is actually within the Milky Way itself, a dwarf Galaxy that is known as Canis Major Gnome Galax (aka. Canis Major).
This star formation is located about 42,000 light-years from the galactic center and only 25,000 light-years from our solar system. This puts it closer to us than the center of our own galaxy, which is 30,000 light-years from the solar system.
Before its discovery, astronomers believed that the Sagittarius Dwarf Galaxy was the closest galactic formation in our own. At 70,000 light-years from Earth, this Galaxy was identified in 1994 to be closer to us than the Large Magellanic Cloud, a dwarf galaxy 180,000 light-years away that previously held the title of our nearest neighbor.
That all changed in 2003, when the dwarf galaxy Canis Major was discovered by the Two Micron Survey Survey (2MASS), an astronomical mission that took place between 1997 and 2001.
Using telescopes located on MT. Hopkins Observatory in Arizona (for the Northern Hemisphere) and at the Inter-American Observatory in Chile in the Southern Hemisphere, astronomers were able to conduct a comprehensive survey of the sky in infrared light, which is not blocked by gas and dust as severely as visible light.
Because of this technique, astronomers have been able to detect a very significant density of class M giant stars in the sky occupied by the constellation Canis Major, as well as several other associated structures within this type of star, two of which have the appearance of wide, swooning arcs (as seen in the image above ).
The prevalence of M-class stars is what made the formation easy to detect. These cool, “red dwarfs” are not very bright compared to other classes of stars, and cannot even be seen with the naked eye. However, they shine very brightly in the infrared, and appeared in large numbers.
In addition to its composition, the Galaxy has a nearly elliptical shape and is believed to contain as many stars as the Sagittarius dwarf elliptical Galaxy, a previous contender for the closest Galaxy to our location in the Milky Way.
In addition to the dwarf galaxy, a long string of stars is visible trailing behind it. This complex, ring structure - sometimes called the Monoceros ring - warps around the galaxy three times. The shower was first discovered in the early 21st century by astronomers conducting the Sloan Digital Sky Survey.
It was during the investigation of this ring of stars, and closely spaced groups of globular clusters similar to those associated with the Sagittarius Dwarf Elliptical Galaxy, that the Canis Major Dwarf Galaxy was discovered.
The current theory is that this galaxy was fused (or absorbed) into the Milky Way Galaxy. Other globular clusters orbiting the center of the Milky Way as a satellite - that is, or NGC 1851, NGC 1904, NGC 2298 and NGC 2808 - are believed to have been part of the Canis Major Dwarf Galaxy before its accretion.
The discovery of this galaxy, and subsequent analysis of the stars associated with it, provides some support for the current theory that galaxies can grow in size by swallowing their smaller neighbors. The Milky Way became what it is now, eating up other galaxies like a big dog, and it continues to do so today. And since the Canis Major Dwarf Galaxy stars are technically already part of the Milky Way, it is by definition the closest Galaxy to us.
Astronomers also believe that the big dog dwarf galaxies are in the process being pulled away by the gravitational field of the more massive Milky Way galaxy. The main body of the galaxy is already extremely degraded, and this process will continue, traveling around and throughout our Galaxy. During accretion, it will likely end with the Great Canis Dwarf Galaxy storing 1 billion of the 200 to 400 billion stars that are already part of the Milky Way.
Before its discovery in 2003, it was the Sagittarius dwarf elliptical galaxy, which held the position of the closest galaxy to our own. 75,000 light years away. This dwarf galaxy, which consists of four globular clusters that measure about 10,000 light-years in diameter, was discovered in 1994. Before this, the Large Magellanic Cloud was thought to be our closest neighbor.
The Andromeda Galaxy (M31) is the closest spiral galaxy to us. Although - gravitationally - it is connected to the Milky Way, it is still not the nearest Galaxy - 2 million light years away. Andromeda is currently approaching our galaxy at a speed of about 110 kilometers per second. In about 4 billion years, the Andromeda Galaxy is expected to merge to form a single Super Galaxy.
A galaxy is a large formation of stars, gas, and dust that is held together by gravity. These largest compounds in the Universe can vary in shape and size. Most space objects are part of a particular galaxy. These are stars, planets, satellites, nebulae, black holes and asteroids. Some of the galaxies have large amounts of invisible dark energy. Due to the fact that galaxies are separated by empty space, they are figuratively called oases in the cosmic desert.
| Elliptical galaxy | Spiral galaxy | Wrong galaxy | |
|---|---|---|---|
| Spheroidal component | The entire galaxy | Eat | Very weak |
| Star disk | None or weakly expressed | Main component | Main component |
| Gas and dust disk | No | Eat | Eat |
| Spiral branches | No or only near the core | Eat | No |
| Active cores | Meet | Meet | No |
| 20% | 55% | 5% |
Our galaxy
The closest star to us, the Sun, is one of the billion stars in the Milky Way galaxy. Looking at the starry night sky, it’s hard not to notice a wide strip strewn with stars. The ancient Greeks called the cluster of these stars the Galaxy.
If we had the opportunity to look at this star system from the outside, we would notice an oblate ball in which there are over 150 billion stars. Our galaxy has dimensions that are hard to imagine. A ray of light travels from one side to the other for hundreds of thousands of Earth years! The center of our Galaxy is occupied by a core, from which huge spiral branches filled with stars extend. The distance from the Sun to the core of the Galaxy is 30 thousand light years. The solar system is located on the outskirts of the Milky Way.
Stars in the Galaxy, despite the huge accumulation of cosmic bodies, are rare. For example, the distance between the nearest stars is tens of millions of times greater than their diameters. It cannot be said that stars are scattered randomly in the Universe. Their location depends on the gravitational forces that hold the celestial body in a certain plane. Stellar systems with their own gravitational fields are called galaxies. In addition to stars, the galaxy includes gas and interstellar dust.
Composition of galaxies.
The Universe is also made up of many other galaxies. The closest ones to us are distant at a distance of 150 thousand light years. They can be seen in the sky of the southern hemisphere in the form of small foggy spots. They were first described by Pigafett, a member of the Magellanic expedition around the world. They entered science under the name of the Large and Small Magellanic Clouds.
The closest galaxy to us is the Andromeda Nebula. It is very large in size, so it is visible from Earth with ordinary binoculars, and in clear weather, even with the naked eye.
The very structure of the galaxy resembles a giant spiral convex in space. On one of the spiral arms, ¾ of the distance from the center, is the Solar System. Everything in the galaxy revolves around the central core and is subject to the force of its gravity. In 1962, astronomer Edwin Hubble classified galaxies depending on their shape. The scientist divided all galaxies into elliptical, spiral, irregular and barred galaxies.
In the part of the Universe accessible to astronomical research, there are billions of galaxies. Collectively, astronomers call them the Metagalaxy.
Galaxies of the Universe
Galaxies are represented by large groups of stars, gas, and dust held together by gravity. They can vary significantly in shape and size. Most space objects belong to some galaxy. These are black holes, asteroids, stars with satellites and planets, nebulae, neutron satellites.
Most galaxies in the Universe contain enormous amounts of invisible dark energy. Since the space between different galaxies is considered empty, they are often called oases in the void of space. For example, a star called the Sun is one of the billions of stars in the Milky Way galaxy located in our Universe. The Solar System is located ¾ of the distance from the center of this spiral. In this galaxy, everything constantly moves around the central core, which obeys its gravity. However, the core also moves with the galaxy. At the same time, all galaxies move at super speeds.
Astronomer Edwin Hubble in 1962 carried out a logical classification of the galaxies of the Universe, taking into account their shape. Now galaxies are divided into 4 main groups: elliptical, spiral, barred and irregular galaxies.
What is the largest galaxy in our Universe?
The largest galaxy in the Universe is a supergiant lenticular galaxy located in the Abell 2029 cluster.
Spiral galaxies
They are galaxies whose shape resembles a flat spiral disk with a bright center (core). The Milky Way is a typical spiral galaxy. Spiral galaxies are usually called with the letter S; they are divided into 4 subgroups: Sa, So, Sc and Sb. Galaxies belonging to the So group are distinguished by bright nuclei that do not have spiral arms. As for the Sa galaxies, they are distinguished by dense spiral arms tightly wound around the central core. The arms of Sc and Sb galaxies rarely surround the core.
Spiral galaxies of the Messier catalog
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Barred galaxies
Bar galaxies are similar to spiral galaxies, but have one difference. In such galaxies, spirals begin not from the core, but from the bridges. About 1/3 of all galaxies fall into this category. They are usually designated by the letters SB. In turn, they are divided into 3 subgroups Sbc, SBb, SBa. The difference between these three groups is determined by the shape and length of the jumpers, where, in fact, the arms of the spirals begin.
Spiral galaxies with the Messier catalog bar
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Elliptical galaxies
The shape of galaxies can vary from perfectly round to elongated oval. Their distinguishing feature is the absence of a central bright core. They are designated by the letter E and are divided into 6 subgroups (according to shape). Such forms are designated from E0 to E7. The former have an almost round shape, while the E7 are characterized by an extremely elongated shape.
Elliptical galaxies of the Messier catalog
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Irregular galaxies
They do not have any distinct structure or shape. Irregular galaxies are usually divided into 2 classes: IO and Im. The most common is the Im class of galaxies (it has only a slight hint of structure). In some cases, helical residues are visible. IO belongs to the class of galaxies that are chaotic in shape. The Small and Large Magellanic Clouds are a prime example of the Im class.
Irregular galaxies of the Messier catalog
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Table of characteristics of the main types of galaxies
| Elliptical galaxy | Spiral galaxy | Wrong galaxy | |
| Spheroidal component | The entire galaxy | Eat | Very weak |
| Star disk | None or weakly expressed | Main component | Main component |
| Gas and dust disk | No | Eat | Eat |
| Spiral branches | No or only near the core | Eat | No |
| Active cores | Meet | Meet | No |
| Percentage of total galaxies | 20% | 55% | 5% |
Large portrait of galaxies
Not long ago, astronomers began working on a joint project to identify the location of galaxies throughout the Universe. Their goal is to obtain a more detailed picture of the overall structure and shape of the Universe on large scales. Unfortunately, the scale of the universe is difficult for many people to comprehend. Take our galaxy, which consists of more than a hundred billion stars. There are billions more galaxies in the Universe. Distant galaxies have been discovered, but we see their light as it was almost 9 billion years ago (we are separated by such a great distance).
Astronomers learned that most galaxies belong to a certain group (it became known as a “cluster”). The Milky Way is part of a cluster, which in turn consists of forty known galaxies. Typically, most of these clusters are part of an even larger grouping called superclusters.
Our cluster is part of a supercluster, which is commonly called the Virgo cluster. Such a massive cluster consists of more than 2 thousand galaxies. At the time when astronomers created a map of the location of these galaxies, superclusters began to take a concrete form. Large superclusters have gathered around what appear to be giant bubbles or voids. What kind of structure this is, no one yet knows. We don't understand what might be inside these voids. According to the assumption, they may be filled with a certain type of dark matter unknown to scientists or have empty space inside. It will be a long time before we know the nature of such voids.
Galactic Computing
Edwin Hubble is the founder of galactic exploration. He is the first to determine how to calculate the exact distance to a galaxy. In his research, he relied on the method of pulsating stars, which are better known as Cepheids. The scientist was able to notice a connection between the period needed to complete one pulsation of brightness and the energy that the star releases. The results of his research became a major breakthrough in the field of galactic research. In addition, he discovered that there is a correlation between the red spectrum emitted by a galaxy and its distance (the Hubble constant).
Nowadays, astronomers can measure the distance and speed of a galaxy by measuring the amount of redshift in the spectrum. It is known that all galaxies in the Universe are moving away from each other. The farther a galaxy is from Earth, the greater its speed of movement.
To visualize this theory, just imagine yourself driving a car moving at a speed of 50 km per hour. The car in front of you is driving 50 km per hour faster, which means that its speed is 100 km per hour. There is another car in front of him, which is moving faster by another 50 km per hour. Even though the speed of all 3 cars will be different by 50 km per hour, the first car is actually moving away from you 100 km per hour faster. Since the red spectrum speaks about the speed of the galaxy moving away from us, the following is obtained: the greater the red shift, the faster the galaxy moves and the greater its distance from us.
We now have new tools to help scientists search for new galaxies. Thanks to the Hubble Space Telescope, scientists were able to see what they could only dream of before. The high power of this telescope provides good visibility of even small details in nearby galaxies and allows you to study more distant ones that have not yet been known to anyone. Currently, new space observation instruments are under development, and in the near future they will help to gain a deeper understanding of the structure of the Universe.
Types of galaxies
- Spiral galaxies. The shape resembles a flat spiral disk with a pronounced center, the so-called core. Our Milky Way galaxy falls into this category. In this section of the portal site you will find many different articles describing space objects of our Galaxy.
- Barred galaxies. They resemble spiral ones, only they differ from them in one significant difference. The spirals do not extend from the core, but from the so-called jumpers. One third of all galaxies in the Universe can be attributed to this category.
- Elliptical galaxies have different shapes: from perfectly round to oval elongated. Compared to spiral ones, they lack a central, pronounced core.
- Irregular galaxies do not have a characteristic shape or structure. They cannot be classified into any of the types listed above. There are much fewer irregular galaxies in the vastness of the Universe.
Astronomers have recently launched a joint project to identify the location of all the galaxies in the Universe. Scientists hope to get a clearer picture of its structure on a large scale. The size of the Universe is difficult for human thought and understanding to estimate. Our galaxy alone is a collection of hundreds of billions of stars. And there are billions of such galaxies. We can see light from discovered distant galaxies, but not even imply that we are looking into the past, because the light beam reaches us over tens of billions of years, such a great distance separates us.
Astronomers also associate most galaxies with certain groups called clusters. Our Milky Way belongs to a cluster that consists of 40 explored galaxies. Such clusters are combined into large groups called superclusters. The cluster with our galaxy is part of the Virgo supercluster. This giant cluster contains more than 2 thousand galaxies. After scientists began to draw a map of the location of these galaxies, superclusters acquired certain shapes. Most galactic superclusters were surrounded by giant voids. No one knows what could be inside these voids: outer space like interplanetary space or a new form of matter. It will take a long time to solve this mystery.
Interaction of galaxies
No less interesting for scientists is the question of the interaction of galaxies as components of cosmic systems. It's no secret that space objects are in constant motion. Galaxies are no exception to this rule. Some types of galaxies could cause a collision or merger of two cosmic systems. If you understand how these space objects appear, large-scale changes as a result of their interaction become more understandable. During the collision of two space systems, a gigantic amount of energy splashes out. The meeting of two galaxies in the vastness of the Universe is an even more probable event than the collision of two stars. Collisions of galaxies do not always end with an explosion. A small space system can freely pass by its larger counterpart, changing its structure only slightly.
Thus, the formation of formations occurs, similar in appearance to elongated corridors. They contain stars and gaseous zones, and new stars are often formed. There are times when galaxies do not collide, but only lightly touch each other. However, even such an interaction triggers a chain of irreversible processes that lead to huge changes in the structure of both galaxies.
What future awaits our galaxy?
As scientists suggest, it is possible that in the distant future the Milky Way will be able to absorb a tiny cosmic-sized satellite system, which is located at a distance of 50 light years from us. Research shows that this satellite has a long life potential, but if it collides with its giant neighbor, it will most likely end its separate existence. Astronomers also predict a collision between the Milky Way and the Andromeda Nebula. Galaxies move towards each other at the speed of light. The wait for a probable collision is approximately three billion Earth years. However, whether it will actually happen now is difficult to speculate due to the lack of data on the movement of both space systems.
Description of galaxies onKvant. Space
The portal site will take you to the world of interesting and fascinating space. You will learn the nature of the structure of the Universe, become familiar with the structure of famous large galaxies and their components. By reading articles about our galaxy, we become more clear about some of the phenomena that can be observed in the night sky.
All galaxies are at a great distance from Earth. Only three galaxies can be seen with the naked eye: the Large and Small Magellanic Clouds and the Andromeda Nebula. It is impossible to count all the galaxies. Scientists estimate that their number is about 100 billion. The spatial distribution of galaxies is uneven - one region may contain a huge number of them, while the second will not contain even a single small galaxy. Astronomers were unable to separate images of galaxies from individual stars until the early 90s. At this time, there were about 30 galaxies with individual stars. All of them were assigned to the Local Group. In 1990, a majestic event took place in the development of astronomy as a science - the Hubble Telescope was launched into Earth orbit. It was this technique, as well as new ground-based 10-meter telescopes, that made it possible to see a significantly larger number of resolved galaxies.
Today, the “astronomical minds” of the world are scratching their heads about the role of dark matter in the construction of galaxies, which manifests itself only in gravitational interaction. For example, in some large galaxies it makes up about 90% of the total mass, while dwarf galaxies may not contain it at all.
Evolution of galaxies
Scientists believe that the emergence of galaxies is a natural stage in the evolution of the Universe, which took place under the influence of gravitational forces. Approximately 14 billion years ago, the formation of protoclusters in the primary substance began. Further, under the influence of various dynamic processes, the separation of galactic groups took place. The abundance of galaxy shapes is explained by the diversity of initial conditions in their formation.
The contraction of the galaxy takes about 3 billion years. Over a given period of time, the gas cloud turns into a star system. Star formation occurs under the influence of gravitational compression of gas clouds. After reaching a certain temperature and density in the center of the cloud, sufficient for the start of thermonuclear reactions, a new star is formed. Massive stars are formed from thermonuclear chemical elements that are more massive than helium. These elements create the primary helium-hydrogen environment. During enormous supernova explosions, elements heavier than iron are formed. It follows from this that the galaxy consists of two generations of stars. The first generation is the oldest stars, consisting of helium, hydrogen and very small amounts of heavy elements. Second-generation stars have a more noticeable admixture of heavy elements because they form from primordial gas enriched in heavy elements.
In modern astronomy, galaxies as cosmic structures are given a special place. The types of galaxies, the features of their interaction, similarities and differences are studied in detail, and a forecast of their future is made. This area still contains a lot of unknowns that require additional study. Modern science has resolved many questions regarding the types of construction of galaxies, but there are also many blank spots associated with the formation of these cosmic systems. The current pace of modernization of research equipment and the development of new methodologies for studying cosmic bodies give hope for a significant breakthrough in the future. One way or another, galaxies will always be at the center of scientific research. And this is based not only on human curiosity. Having received data on the patterns of development of cosmic systems, we will be able to predict the future of our galaxy called the Milky Way.
The most interesting news, scientific, and original articles about the study of galaxies will be provided to you by the website portal. Here you can find exciting videos, high-quality images from satellites and telescopes that will not leave you indifferent. Dive into the world of unknown space with us!