Big Encyclopedic Dictionary
Extragalactic nebulae or island universes, giant star systems that also contain interstellar gas and dust. The solar system is part of our Milky Way Galaxy. All outer space to the limits where they can penetrate... ... Collier's Encyclopedia
Giant (up to hundreds of billions of stars) star systems; These include, in particular, our Galaxy. Galaxies are divided into elliptical (E), spiral (S) and irregular (Ir). The closest galaxies to us are the Magellanic Clouds (Ir) and the nebula... ... encyclopedic Dictionary
Giant star systems, similar to our star system Galaxy (See Galaxy), which includes the Solar system. (The term “galaxies”, in contrast to the term “Galaxy”, is written with a lowercase letter.) The obsolete name G. ... ...
Giant (up to hundreds of billions of stars) star systems; These include, in particular, our Galaxy. Galaxies are divided into elliptical (E), spiral (S) and irregular (Ir). The closest galaxies to us are the Magellanic Clouds (Ir) and the nebula... ... Astronomical Dictionary
Galaxies- giant star systems with the number of stars from tens to hundreds of billions each. Modern estimates give about 150 million galaxies in the Metagalaxy known to us. Galaxies are divided into elliptical (denoted in astronomy by the letter E),... ... The beginnings of modern natural science
Giant (up to hundreds of billions of stars) star systems; These include, in particular, our Galaxy. G. are divided into elliptical. (E), spiral (S) and irregular (Ir). The closest to us are the G. Magellanic Clouds (Ir) and the Andromeda Nebula (S). G.… … Natural science. encyclopedic Dictionary
The Whirlpool Galaxy (M51) and its satellite NGC 5195. Photograph of the Kitt Peak Observatory. Interacting galaxies are galaxies located close enough in space that mutual gravity is significantly ... Wikipedia
Stellar systems that differ in shape from spiral and elliptical ones by being chaotic and ragged. Sometimes there are N. g., which do not have a clear shape, are amorphous. They consist of stars mixed with dust, while most N. g.... ... Big Soviet encyclopedia
- ... Wikipedia
Books
- Galaxies, Avedisova Veta Sergeevna, Surdin Vladimir Georgievich, Vibe Dmitry Zigfridovich. The fourth book in the "Astronomy and Astrophysics" series contains an overview of modern ideas about giant star systems - galaxies. It tells about the history of the discovery of galaxies, about their...
- Galaxies, Surdin V.G.. The fourth book in the series “Astronomy and Astrophysics” contains an overview of modern ideas about giant star systems - galaxies. It tells about the history of the discovery of galaxies, about their...
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, one might say, Milky Way 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 ours. 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 were able to detect a very significant density of class M giant stars in the sky occupying the constellations big dog, 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 with Milky Way, this is still not the nearest Galaxy - 2 million light years from us. 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.
What is the distance to the nearest galaxy? March 12th, 2013
For the first time, scientists have been able to measure the exact distance to our nearest galaxy. This dwarf galaxy is known as Large Magellanic Cloud. It is located at a distance of 163 thousand light years from us, or 49.97 kiloparsecs, to be precise.
The Large Magellanic Cloud galaxy slowly floats through space, bypassing our galaxy Milky Way around just as the Moon revolves around the Earth.
Huge clouds of gas in the region of the galaxy slowly dissipate, resulting in the formation of new stars that illuminate interstellar space with their light, creating bright, colorful cosmic landscapes. A space telescope was able to capture these landscapes in photographs. "Hubble".
The shallow galaxy Large Magellanic Cloud includes the Tarantula Nebula - the brightest stellar nursery in space in our neighborhood - and has shown signs of new star formation.
Scientists were able to make the calculations by observing rare close pairs of stars known as eclipsing double stars. These pairs of stars are gravitationally bound to each other, and when one star eclipses the other, as seen by an observer on Earth, the overall brightness of the system decreases.
If you compare the brightness of stars, you can calculate the exact distance to them with incredible accuracy.
Determining the exact distance to space objects is very important for understanding the size and age of our Universe. For now, the question remains open: none of the scientists can say for sure what the size of our Universe is yet.
Once astronomers have achieved such precision in determining distances in space, they will be able to look at more distant objects and, ultimately, be able to calculate the size of the Universe.
Also, new capabilities will make it possible to more accurately determine the expansion rate of our Universe, as well as more accurately calculate Hubble constant. This coefficient was named after Edwin P. Hubble, an American astronomer who proved in 1929 that our Universe has been constantly expanding since its beginning.
Distance between galaxies
The Large Magellanic Cloud Galaxy is the closest dwarf galaxy to us, but a large galaxy is considered our neighbor Andromeda spiral galaxy, which is located at a distance of about 2.52 million light years from us.
The distance between our galaxy and the Andromeda galaxy is gradually decreasing. They are approaching each other at a speed of approximately 100-140 kilometers per second, although they will not meet very soon, or rather, in 3-4 billion years.
Perhaps this is what the night sky will look like to an observer on Earth in a few billion years.
The distances between galaxies can thus be very different at different stages of time, since they are constantly in dynamics.
Scale of the Universe
The visible Universe has an incredible diameter, which is billions, and maybe tens of billions of light years. Many objects that we can see with telescopes no longer exist or look completely different because the light took an incredibly long time to reach them.
The proposed series of illustrations will help you imagine at least general outline the scale of our Universe.
The solar system with its largest objects (planets and dwarf planets)
The Sun (in the center) and the stars closest to it
The Milky Way Galaxy, showing the group of star systems closest to the Solar System
A group of nearby galaxies, including more than 50 galaxies, the number of which is constantly increasing as new ones are discovered.
Local supercluster of galaxies (Virgo Supercluster). Size - about 200 million light years
Group of superclusters of galaxies
Visible Universe
Fixing its gaze on the stars, humanity has long wanted to find out what is there - in the abyss of space, what laws are there and whether there are intelligent beings. We live in the 21st century, this is a time when space flights are an ordinary part of our lives, of course, people do not yet fly on spaceships, like on airplanes on Earth, but reports of the launches and landings of all kinds of research probes are already quite commonplace. So far, only the Moon, our satellite, has become the first and only extraterrestrial object where a person has set foot; the next stage will be the landing of a person on Mars. But in this article we will not talk about the “red planet” or even the nearest star, we will discuss the curious question of what is the distance to the nearest galaxy. Although from a technical point of view such long flights are not feasible at the moment, it is still interesting to know the approximate timing of the “journey”.
If you read our article about that, you will understand that moving a spaceship to a nearby galaxy is something unimaginable. With technology today It’s very difficult to fly, let alone to a galaxy, to a star. However, this seems impossible if we rely on the classical laws of physics (you cannot exceed the speed of light) and the technology of burning fuel in engines, no matter how advanced they are. First, let's talk about the distance between our galaxy and the nearest one so that you understand the enormous scale of the hypothetical journey.
Distances to nearby galaxies
We live in a galaxy called the Milky Way, which has a spiral structure and contains approximately 400 billion stars. Light travels the distance from one end to the other in about one hundred thousand years. The closest to ours is the Andromeda galaxy, which also has a spiral structure, but is more massive, containing approximately one trillion stars. The two galaxies are gradually approaching each other at a speed of 100-150 kilometers per second; in four billion years they will “merge” into a single whole. If after so many years people still live on Earth, they will not notice any transformations other than a gradual change in the starry sky, because... distances between stars, then the chances of collision are very small.
The distance to the nearest galaxy is approximately 2.5 million light years, i.e. Light from the Andromeda Galaxy takes 2.5 million years to reach the Milky Way.
There is also a “mini-galaxy”, which was called the “Large Magellanic Cloud”, it is small in size and is gradually decreasing; the Magellanic Cloud will not collide with our galaxy, because has a different trajectory. The distance to this galaxy is approximately 163 thousand light years, it is the closest to us, but because of its size, scientists prefer to call the Andromeda galaxy closest to us.
To fly to Andromeda on the fastest and most modern spaceship built to date, it will take as much as 46 billion years! It’s easier to “wait” until she herself flies to the Milky Way “in just” 4 billion years.
High-speed "dead end"
As you understand from this article, it is “problematic” for even light to reach the nearest galaxy; intergalactic distances are enormous. Humanity needs to look for other ways to move in outer space than “standard” fuel engines. Of course, on at this stage Our development in this direction needs to be “digged”, the development of high-speed engines will help us quickly explore the vastness of our solar system, people will be able to set foot not only on Mars, but also on other planets, for example, Titan - the satellite of Saturn, which has long been of interest to scientists.
Perhaps, on an improved spaceship, people will be able to fly even to Proxima Centauri, the closest star to us, and if humanity learns to reach the speed of light, then it will be possible to fly to nearby stars in years, not millennia. If we talk about intergalactic flights, then we need to look for completely different ways of moving in space.
Possible ways to overcome huge distances
Scientists have long been trying to understand the nature of “” - massive objects with such strong gravity that even light cannot escape from their depths; scientists suggest that the supergravity of such “holes” can break through the “fabric” of space and open paths to some other points of our Universe. Even if this is true, the method of traveling through black holes has several disadvantages, the main one of which is “unplanned” movement, i.e. people on a spaceship will not be able to choose a point in the Universe where they want to go, they will fly to where the hole “wants”.
Also, such a journey can become one-way, because... the hole may collapse or change its properties. In addition, strong gravity can affect not only space, but also time, i.e. the astronauts will fly as if into the future, for them time will flow as usual, but on Earth years or even centuries may pass before their return (this paradox is well shown in the recent film “Interstellar”).
Scientists involved in quantum mechanics have discovered an amazing fact: it turns out that the speed of light is not the limit of movement in the Universe, at the micro level there are particles that appear for an instant at one point in space, and then disappear and appear in another, the distance for them has no meanings.
“String theory” states that our world has a multidimensional structure (11 dimensions), perhaps by understanding these principles, we will learn to move to any distance. To a spaceship He won’t even need to fly anywhere and accelerate, while standing still, he will be able, with the help of some kind of gravitational generator, to collapse space, thereby getting to any point.
The power of scientific progress
The scientific world should pay more attention to the microcosm, because perhaps this is where the answers to the questions of rapid movement throughout the Universe lie; without revolutionary discoveries in this area, humanity will not be able to overcome large cosmic distances. Fortunately, for these studies, a powerful particle accelerator was built - the Large Hadron Collider, which will help scientists understand the world of elementary particles.
We hope that in this article we have talked in detail about the distance to the nearest galaxy; we are sure that sooner or later a person will learn to overcome distances of millions of light years, perhaps then we will meet our “brothers” in mind, although the author of these lines believes that this will happen sooner. You can write a separate treatise on the meaning and consequences of the meeting; this, as they say, is “another story.”
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 irregular shape 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.
