Rice. Fig. 15. Galaxy NGC 6814, similar to our Galaxy, observed in plan Galaxy, similar to ours, when observed in plan, look like the galaxy NGC 6814, shown in Figure 15.
Spiral branches, sleeves, emerge from the core of the galaxy. They go around the core and, gradually expanding and branching, lose their brightness. At a certain distance, their trail disappears altogether.
Studies have shown that the spiral arms of other galaxies consist of stars - hot giants and supergiants, as well as dust and gas (hydrogen). If the listed objects are removed from spiral galaxies, then their branches-sleeves will disappear. Their spiral structure will disappear. The point is that red and yellow stars, both dwarfs and giants, equally fill both the regions in the spiral arms and the regions between the spiral arms.
If we want to study the spiral structure of our Galaxy, we must trace the location of stars in it - hot giants, as well as dust and gas. But it is not easy to do this, since we are forced to observe the spiral structure of the Galaxy from the inside. In this case, the various parts of the spiral arms are projected onto each other. Our task is complicated by the fact that we do not know how to accurately determine the distance to distant stars - hot giants. It can be said that it is generally impossible to measure large distances in the Galaxy - primarily because of the dusty matter that absorbs the light of stars. Spiral arms are located in the plane of the Galaxy. That's where most of the dust is. But dusty matter not only absorbs light and makes it difficult to measure distances. It makes very distant stars - hot giants - practically invisible. It is for them that we must follow if we want to know the location of the spiral arms. Thus, it is not possible to study the spiral branches of our Galaxy by observing the distribution in space of stars - hot giants or stellar associations.
Certain information about spiral arms can be obtained by using neutral hydrogen radiation at a wavelength of 21 centimeters. We have already said that in this way it is possible to derive the law of rotation of the Galaxy. The density of neutral hydrogen was measured in various places in the Galaxy. The results of these measurements are shown in Figure 16. It can be seen that there were no observations in two small sectors. Nevertheless, the arrangement of spiral branches is visible. The fact is that hydrogen usually coexists with stars - hot giants. They determine the shape of the spiral arms. Therefore, the places of hydrogen condensation should repeat the pattern of the spiral structure of the Galaxy.
As already mentioned, the radiation of neutral hydrogen with a wavelength of 21 centimeters is in the radio range. Dust has no effect on it. Therefore, it reaches us from the most distant regions of the Galaxy.
For a long time, astronomers have been arguing about how many spiral arms the Milky Way has: four (like a swastika) or two?
New evidence has been obtained that the Milky Way has four spiral arms.
The spiral structure of our galaxy is not well understood. Most scientists believe that the Milky Way has four spiral arms, but relatively recent observations with NASA's Spitzer Telescope have led researchers to doubt this. The data received from the telescope suggested that our galaxy has only two spiral arms. In 2013, when astronomers were mapping star-forming regions, they discovered two lost spiral arms. Thus, the researchers returned to the version according to which there are 4 arms in our galaxy.
Recently, another piece of evidence has been put forward in support of this version.
A team of Brazilian astronomers have been studying star clusters to trace the structure of the galaxy. “Our results support the theory that our galaxy has four arms. The latter include the Perseus arm, the Sagittarius arm, and the two outer arms., - say researchers from the Federal University of Rio Grande DO Sul.
“Despite all our efforts to better understand the structure of the galaxy, there are still a lot of questions. There is no consensus among scientists on the number and shape of the galaxy's spiral arms,” said study lead author D. Camargo. He also added that the location of the sun on the obscured disk of the galaxy was a major factor hindering our understanding of the wider structure of the Milky Way. In other words, we cannot study our galaxy from a bird's eye view.
The team of researchers noted that young embedded clusters make it possible to perfectly trace the structure of the galaxy. "The results of the latest study show that the embedded clusters of the galaxy are predominantly located in the spiral arms," the scientists explain. They also note that star formation may occur after the breakup and fragmentation of the giant molecular clouds found in the spiral arms. The young embedded star clusters that emerge later make it possible to study the structure of the galaxy, since they do not move far from their birthplace.
To identify young implanted clusters, the team of researchers used data from NASA's WISE infrared telescope. So, scientists managed to find 7 new embedded clusters, some of which may be part of a larger cluster located in the Perseus arm. They hypothesized that giant molecular clouds were compressed by a spiral arm, which could be the cause of numerous star clusters, similar in age.
The team also used data from the 2MASS infrared sky survey to determine the distance to the discovered star clusters. The study was aimed at establishing the exact fundamental parameters of the cluster and, as a result, obtaining new information about the structure of the galaxy.
The science
Each person has their own idea of what a home is. For some it's a roof over their heads, for others home is planet Earth, a rocky ball that plows outer space along its closed path around the Sun.
No matter how big our planet seems to us, it is just a grain of sand in giant star system whose size is hard to imagine. This star system is the Milky Way galaxy, which can also rightly be called our home.
Arms of the galaxy
Milky Way- a spiral galaxy with a bar that runs along the center of the spiral. Approximately two-thirds of all known galaxies are spiral, and two-thirds of them are barred. That is, the Milky Way is included in the list most common galaxies.
Spiral galaxies have arms that extend out from the center like wheel spokes that spiral. Our solar system is located in the central part of one of the arms, which is called Orion arm.
The Orion Arm was once thought to be a small "offshoot" of larger arms such as Perseus arm or Shield-Centaurus arm. Not so long ago there was an assumption that the Orion arm is indeed offshoot of the Perseus arm and does not leave the center of the galaxy.
The problem is that we cannot see our galaxy from the outside. We can observe only those things that are around us, and judge what shape the galaxy has, being, as it were, inside it. However, scientists were able to calculate that this sleeve has a length of approximately 11 thousand light years and thickness 3500 light years.
Supermassive black hole
The smallest supermassive black holes that scientists have discovered are approximately in 200 thousand times heavier than the sun. For comparison: ordinary black holes have the mass of everything 10 times greater than the mass of the sun. At the center of the Milky Way is an incredibly massive black hole, the mass of which is hard to imagine. 
For the past 10 years, astronomers have been monitoring the activity of stars in orbit around the star. Sagittarius A, the dense region at the center of our galaxy's spiral. Based on the movement of these stars, it was determined that at the center Sagittarius A*, which is hidden behind a dense cloud of dust and gas, there is a supermassive black hole whose mass is 4.1 million times more than the mass of the sun!
The animation below shows the real movement of stars around a black hole. from 1997 to 2011 around one cubic parsec at the center of our galaxy. As stars approach a black hole, they loop around it at incredible speeds. For example, one of these stars, S 0-2 moving at a speed 18 million kilometers per hour: black hole first attracts it, and then sharply repels it.
More recently, scientists observed how a cloud of gas approached a black hole and was torn to pieces its massive gravitational field. Parts of this cloud were swallowed up by the hole, and the remaining parts began to resemble long thin pasta more than 160 billion kilometers.
Magneticparticles
In addition to having a supermassive all-consuming black hole, the center of our galaxy boasts incredible activity: old stars die, and new ones are born with enviable constancy.
Not so long ago, scientists noticed something else at the galactic center - a stream of high-energy particles that extend into the distance 15 thousand parsecs across the galaxy. This distance is about half the diameter of the Milky Way.
The particles are invisible to the naked eye, however, using magnetic imaging, you can see that the particle geysers take up about two thirds of the visible sky:
What is behind this phenomenon? For one million years, stars have come and gone, feeding never stopping flow, directed towards the outer arms of the galaxy. The total energy of a geyser is a million times greater than that of a supernova.
The particles move at an incredible speed. Based on the structure of the particle stream, astronomers built magnetic field model that dominates our galaxy.
Newstars
How often do new stars form in our galaxy? Researchers have been asking this question for years. It was possible to map the areas of our galaxy where there is aluminum-26, an isotope of aluminum that appears where stars are born or die. Thus, it was possible to find out that every year in the Milky Way galaxy, 7 new stars and about twice in a hundred years a large star explodes, forming a supernova.
The Milky Way galaxy is not the largest producer of stars. When a star dies, it releases into space such raw materials, like hydrogen and helium. After hundreds of thousands of years, these particles coalesce into molecular clouds, which eventually become so dense that their center collapses under their own gravity, thus forming a new star.
It looks like a kind of eco-system: death feeds new life. Particles of a particular star in the future will be part of a billion new stars. This is how things are in our galaxy, so it evolves. This leads to the formation of new conditions under which the probability of the emergence of planets similar to the Earth increases.
Planets of the Milky Way Galaxy
Despite the constant death and birth of new stars in our galaxy, their number has been calculated: The Milky Way is home to about 100 billion stars. Based on new research, scientists suggest that every star has at least one or more planets orbiting it. That is, everything in our corner of the universe has 100 to 200 billion planets.
The scientists who came to this conclusion studied stars like red dwarfs of spectral class M. These stars are smaller than our Sun. They make up 75 percent from all the stars in the Milky Way. In particular, the researchers drew attention to the star Kepler-32, who sheltered five planets.
How do astronomers discover new planets?Planets, unlike stars, are difficult to detect because they do not emit their own light. We can say with certainty that there is a planet around a star only when it stands in front of his star and obscures its light.
The planets of the star Kepler -32 behave exactly like exoplanets orbiting other M dwarf stars. They are located approximately at the same distance and have similar sizes. That is, the Kepler-32 system is typical system for our galaxy.
If there are over 100 billion planets in our galaxy, how many planets are Earth-like? It turns out, not so much. There are dozens of different types of planets: gas giants, pulsar planets, brown dwarfs, and planets that rain molten metal from the sky. Those planets that are composed of rocks can be located too far or too close to the star, so they are hardly similar to the Earth.
The results of recent studies have shown that in our galaxy, it turns out that there are more terrestrial planets than previously thought, namely: 11 to 40 billion. The scientists took as an example 42 thousand stars, similar to our Sun, and began to look for exoplanets that can revolve around them in a zone where it is not too hot and not too cold. Was found 603 exoplanets, among which 10 matched the search criteria.
By analyzing stellar data, scientists have proven the existence of billions of Earth-like planets that they have yet to officially discover. Theoretically, these planets are able to maintain temperatures for existence of liquid water which, in turn, will allow life to emerge.
Collision of galaxies
Even if new stars are constantly formed in the Milky Way galaxy, it will not be able to increase in size, unless it gets new material from somewhere else. And the Milky Way is really expanding.
Previously, we were not sure exactly how the galaxy manages to grow, but recent discoveries have suggested that the Milky Way is cannibal galaxy, meaning it has devoured other galaxies in the past and will likely do so again, at least until some larger galaxy engulfs it.
Using a space telescope Hubble and information gained from photographs taken over the course of seven years, scientists have discovered stars near the outer edge of the Milky Way, which moving in a special way. Instead of moving towards or away from the center of the galaxy like other stars, they sort of drift off the edge. It is assumed that this star cluster is all that is left of another galaxy that was swallowed up by the Milky Way galaxy.
This collision appears to have taken place several billion years ago and it probably won't be the last. Given the speed at which we are moving, our galaxy through 4.5 billion years will collide with the Andromeda galaxy.
Influence of satellite galaxies
Although the Milky Way is a spiral galaxy, it is not exactly a perfect spiral. At its center there is peculiar bulge, which appeared as a result of the fact that the molecules of gaseous hydrogen escape from the flat disk of the spiral.
For years, astronomers have puzzled over why the galaxy has such a bulge. It is logical to assume that the gas is drawn into the disk itself, and does not break out. The longer they studied this issue, the more confused they became: the bulge molecules are not only pushed outward, but also vibrate at their own frequency.
What can cause such an effect? Today, scientists believe that dark matter and satellite galaxies are to blame - Magellanic Clouds. These two galaxies are very small: together they make up only 2 percent of the total mass of the Milky Way. It's not enough to have an impact on him.
However, when dark matter moves through the Clouds, it creates waves that apparently affect the gravitational attraction, strengthening it, and hydrogen under the influence of this attraction escaping from the center of the galaxy.
The Magellanic Clouds revolve around the Milky Way. The spiral arms of the Milky Way, under the influence of these galaxies, seem to sway in the place where they float.
twin galaxies
Although the Milky Way galaxy can be called unique in many ways, it is not a rarity. The universe is dominated by spiral galaxies. Considering that only in our field of vision are about 170 billion galaxies, we can assume that somewhere there are galaxies very similar to ours.
But what if somewhere there is a galaxy - an exact copy of the Milky Way? In 2012, astronomers discovered such a galaxy. It even has two small satellites that orbit it and match exactly with our Magellanic Clouds. By the way, only 3 percent spiral galaxies have similar companions whose lifetimes are relatively short. The Magellanic Clouds are likely to dissolve in a couple of billion years.
Finding such a similar galaxy with satellites, a supermassive black hole in the center and the same size is an incredible stroke of luck. This galaxy is called NGC 1073 and it looks so much like the Milky Way that astronomers study it to find out more. about our own galaxy. For example, we can see it from the side and thus better imagine what the Milky Way looks like.
Galactic year
On Earth, a year is the time it takes the Earth to make complete revolution around the sun. Every 365 days we return to the same point. Our solar system revolves around the black hole at the center of the galaxy in the same way. However, it makes a full turn for 250 million years. That is, since the dinosaurs disappeared, we have made only a quarter of a complete revolution.
In descriptions of the solar system, it is rarely mentioned that it moves in outer space, like everything else in our world. Relative to the center of the Milky Way, the solar system moves at a speed 792 thousand kilometers per hour. For comparison: if you were moving at the same speed, you could travel around the world in 3 minutes.
The period of time it takes for the Sun to make a complete revolution around the center of the Milky Way is called galactic year. It is estimated that the Sun has lived only 18 galactic years.
> Milky Way
Milky Way- spiral galaxy with solar system: interesting facts, size, area, discovery and name, research with video, structure, location.
The Milky Way is a spiral galaxy covering an area of 100,000 light years in which the solar system is located.
If you have a place away from the city, where darkness reigns and a beautiful view of the starry sky opens up, you may notice a faint light streak. This is a group with millions of small bright lights and luminous halos. Stars in front of you galaxy milky way.
But what does she represent? Let's start with the fact that the Milky Way is a spiral type of barred galaxy, on the territory of which the solar system lives. It is difficult to call the native galaxy something unique, because there are hundreds of billions of galaxies in the Universe, and many are similar.
Interesting facts about the Milky Way galaxy
- The Milky Way began forming as a cluster of dense regions after the Big Bang. The first stars to appear were in globular clusters that continue to exist. These are the oldest stars in the galaxy;
- The galaxy has increased its parameters by absorbing and merging with others. Now she is picking stars from the Sagittarius Dwarf Galaxy and the Magellanic Clouds;
- The Milky Way moves in space with an acceleration of 550 km / s with respect to the background radiation;
- Lurking at the galactic center is the supermassive black hole Sagittarius A*. By mass, it is 4.3 million times greater than the solar one;
- Gas, dust and stars revolve around the center at a speed of 220 km/s. This is a stable indicator, implying the presence of a shell of dark matter;
- In 5 billion years, a collision with the Andromeda galaxy is expected. Some believe that the Milky Way is a double system of a giant spiral;
Discovery and naming of the Milky Way galaxy
Our galaxy, the Milky Way, has a rather interesting name, as the hazy haze resembles a milk trail. The name has ancient roots and is translated from the Latin "Via Lactea". This name appears already in the work "Tadhira" by Nasir ad-Din Tusi. He wrote: “Represented by many small and densely grouped stars. They are located close, so they appear to be spots. The color resembles milk ... ". Admire the photo of the Milky Way galaxy with its arms and center (of course, no one can take a photo of our galaxy, but there are similar constructions and accurate data on the structure, on the basis of which an idea is formed of the appearance of the galactic center and arms).
Scientists thought the Milky Way was filled with stars, but that was just a guess until 1610. That's when Galileo Galilei points the first telescope into the sky and sees individual stars. It also revealed to people a new truth: there are many more stars than we thought, and they are part of the Milky Way.
Immanuel Kant in 1755 believed that the Milky Way is a collection of stars held together by a common gravity. The gravitational force causes objects to rotate and flatten into a disc shape. In 1785, William Herschel tried to recreate the galactic shape, but did not realize that most of it is hidden behind a dust and gas haze.
The situation changes in the 1920s. Edwin Hubble was able to convince that we see not spiral nebulae, but individual galaxies. It was then that it became possible to realize the form of ours. From that moment it became clear that this is a barred spiral galaxy. Watch the video to study the structure of the Milky Way galaxy and explore its globular clusters and find out how many stars live in the galaxy.
Our galaxy: a look from the inside
Astrophysicist Anatoly Zasov about the main components of our galaxy, the interstellar medium and globular clusters:
Location of the Milky Way galaxy
The Milky Way is quickly recognizable in the sky due to the wide and elongated white line resembling a milk trail. Interestingly, this stellar group has been available for review since the formation of the planet. In fact, this area acts as the galactic center.
The galaxy spans 100,000 light-years in diameter. If you could look at it from above, you would notice a bulge in the center, from which 4 large spiral arms emanate. This type represents 2/3 of the universal galaxies.
Unlike the usual spiral, barred specimens accommodate a rod in the center with two branches. Our galaxy has two main arms and two minor ones. Our system is located in the Orion arm.
The Milky Way is not static and rotates in space, carrying all objects with it. The solar system moves around the galactic center at a speed of 828,000 km/h. But the galaxy is incredibly huge, so it takes 230 million years to make one pass.
A lot of dust and gas accumulates in spiral arms, which creates excellent conditions for the formation of new stars. The arms radiate from a galactic disk that spans roughly 1,000 light-years.
At the center of the Milky Way, you can see a bulge filled with dust, stars and gas. It is because of this that you can only see a small percentage of the total number of galactic stars. It's all about the thick gas and dust haze that blocks the view.
Hidden in the very center is a supermassive black hole, billions of times the mass of the Sun. Most likely, it used to be much smaller, but a regular diet of dust and gas allowed it to grow. This is an incredible glutton, because sometimes it even sucks the stars. Of course, it is impossible to see it directly, but the gravitational influence is monitored.
Around the galaxy is a halo of hot gas, where old stars and globular clusters live. It stretches for hundreds of thousands of light years, but contains only 2% of the stars of those in the disk. Let's not forget about dark matter (90% of the galactic mass).
Structure and composition of the Milky Way galaxy
When observed, it is clear that the Milky Way divides the celestial space into two almost identical hemispheres. This suggests that our system is located near the galactic plane. It is noticeable that the galaxy has a low level of surface brightness due to the fact that gas and dust are concentrated in the disk. This not only makes it impossible to see the galactic center, but also to understand what is hidden on the other side. You can easily locate the center of the Milky Way galaxy in the diagram below.
If you managed to break out of the Milky Way and get a perspective for a view from above, then you would see a spiral with a bar in front of you. Extends 120,000 light years and 1,000 light years wide. For many years, scientists thought they saw 4 arms, but there are only two of them: the Shield-Centaurus and Sagittarius.
The arms are created by dense waves rotating around the galaxy. They move around the area, so they squeeze dust and gas. This process triggers the active birth of stars. This happens in all galaxies of this type.
If you have come across photos of the Milky Way, then they are all artistic interpretations or other similar galaxies. It was difficult for us to comprehend its appearance, since we are located inside. Imagine that you want to describe the outside of a house if you have never left its walls. But you can always look out the window and look at the neighboring buildings. In the figure below, you can easily understand where the solar system is located in the Milky Way galaxy.
Ground and space missions have made it possible to understand that 100-400 billion stars live in the galaxy. Each of them can have one planet, that is, the Milky Way galaxy is capable of sheltering hundreds of billions of planets, 17 billion of which are similar in size and mass to the Earth.
Approximately 90% of the galactic mass goes into dark matter. No one can ever explain what we are facing. In principle, it has not yet been seen, but we know about the presence due to the rapid galactic rotation and other influences. It is she who keeps the galaxies from destruction during rotation. Watch the video to learn more about the stars in the Milky Way.
The stellar population of the galaxy
Astronomer Alexei Rastorguev on the age of stars, star clusters and properties of the galactic disk:
The position of the Sun in the Milky Way galaxy
Between the two main arms is the Orion arm, in which our system is located 27,000 light-years from the center. It is not worth complaining about the remoteness, because a supermassive black hole (Sagittarius A *) lurks in the central part.
Our Sun star takes 240 million years to circle the galaxy (a space year). This sounds incredible, because the last time the Sun was in the area, dinosaurs roamed the Earth. During its entire existence, the star has made approximately 18-20 flybys. That is, it was born 18.4 space years ago, and the age of the galaxy is 61 space years.
Collision trajectory of the Milky Way galaxy
The Milky Way not only rotates, but also moves in the Universe itself. And although the space is large, no one is immune from collisions.
According to calculations, in about 4 billion years, our Milky Way galaxy will collide with the Andromeda galaxy. They are approaching at a speed of 112 km/s. After the collision, the process of star birth is activated. In general, Andromeda is not the most accurate racer, as it has already crashed into other galaxies in the past (a noticeable large dust ring in the center).
But earthlings should not worry about the future event. After all, by that time the Sun will have exploded and destroyed our planet.
What's next for the Milky Way galaxy?
The Milky Way is believed to have come into being from a merger of smaller galaxies. This process continues as the Andromeda galaxy is already rushing towards us in order to create a giant ellipse in 3-4 billion years.
The Milky Way and Andromeda do not exist in isolation, but are part of the Local Group, which is also part of the Virgo Supercluster. This gigantic region (110 million light-years) contains 100 groups and galaxy clusters.
If you have not been able to admire your native galaxy, then do it as soon as possible. Find a quiet and dark place with an open sky and just enjoy this amazing star collection. Recall that the site has a virtual 3D model of the Milky Way galaxy, which allows you to study all the stars, clusters, nebulae and known planets online. And our star map will help you find all these celestial bodies in the sky on your own if you decide to buy a telescope.
The position and movement of the Milky Way
The starry sky has attracted the eyes of people since ancient times. The best minds of all peoples tried to comprehend our place in the Universe, to imagine and justify its structure. Scientific progress made it possible to move in the study of the vast expanses of space from romantic and religious constructions to logically verified theories based on numerous factual material. Now any schoolchild has an idea of what our Galaxy looks like according to the latest research, who, why and when gave it such a poetic name and what its supposed future is.
origin of name
The expression "the Milky Way galaxy" is, in fact, a tautology. Galactikos roughly translated from ancient Greek means "milk". So the inhabitants of the Peloponnese called the cluster of stars in the night sky, attributing its origin to the quick-tempered Hera: the goddess did not want to feed Hercules, the illegitimate son of Zeus, and splashed her breast milk in anger. Drops and formed a star track, visible on clear nights. Centuries later, scientists discovered that the observed luminaries are only an insignificant part of the existing celestial bodies. They gave the name of the Galaxy or the Milky Way system to the space of the Universe, in which our planet is also located. After confirming the assumption of the existence of other similar formations in space, the first term became universal for them.
Inside view
Scientific knowledge about the structure of the part of the universe, including the solar system, took little from the ancient Greeks. The understanding of what our Galaxy looks like has evolved from the spherical universe of Aristotle to modern theories, in which there is a place for black holes and dark matter.
The fact that the Earth is an element of the Milky Way system imposes certain restrictions on those who are trying to figure out what shape our galaxy has. An unequivocal answer to this question requires a view from the side, and at a great distance from the object of observation. Now science is deprived of such an opportunity. A kind of substitute for an outside observer is the collection of data on the structure of the Galaxy and their correlation with the parameters of other space systems available for study.
The collected information allows us to say with confidence that our Galaxy has the shape of a disk with a thickening (bulge) in the middle and spiral arms diverging from the center. The latter contain the brightest stars in the system. The disk is over 100,000 light-years across.
Structure
The center of the Galaxy is hidden by interstellar dust, which makes it difficult to study the system. The methods of radio astronomy help to cope with the problem. Waves of a certain length easily overcome any obstacles and allow you to get such a desired image. Our Galaxy, according to the data obtained, has an inhomogeneous structure.
It is conditionally possible to distinguish two elements connected with each other: the halo and the disk itself. The first subsystem has the following characteristics:
- in shape it is a sphere;
- its center is considered to be the bulge;
- the highest concentration of stars in the halo is characteristic of its middle part, with approaching the edges, the density strongly decreases;
- the rotation of this zone of the galaxy is rather slow;
- the halo mostly contains old stars with a relatively small mass;
- a significant space of the subsystem is filled with dark matter.
The galactic disk in terms of the density of stars greatly exceeds the halo. In the sleeves there are young and even just emerging
Center and core
The "heart" of the Milky Way is located in Without studying it, it is difficult to fully understand what our Galaxy is like. The name "core" in scientific writings either refers only to the central region with a diameter of only a few parsecs, or includes the bulge and gas ring, which is considered the birthplace of stars. In what follows, the first version of the term will be used.
Visible light struggles to penetrate the center of the Milky Way as it collides with a lot of cosmic dust that obscures what our Galaxy looks like. Photos and images taken in the infrared range greatly expand the knowledge of astronomers about the nucleus.
Data on the features of radiation in the central part of the Galaxy led scientists to the idea that there is a black hole in the core of the nucleus. Its mass is more than 2.5 million times the mass of the Sun. Around this object, according to researchers, another, but less impressive in its parameters, black hole rotates. Modern knowledge about the features of the structure of the cosmos suggests that such objects are located in the central part of most galaxies.
Light and darkness
The joint influence of black holes on the movement of stars makes its own adjustments to how our Galaxy looks: it leads to specific changes in orbits that are not typical for cosmic bodies, for example, near the solar system. The study of these trajectories and the ratio of motion velocities with distance from the center of the Galaxy formed the basis of the currently actively developing theory of dark matter. Its nature is still shrouded in mystery. The presence of dark matter, presumably constituting the vast majority of all matter in the Universe, is registered only by the effect of gravity on orbits.
If we dispel all the cosmic dust that the core hides from us, a striking picture opens up. Despite the concentration of dark matter, this part of the universe is full of light emitted by a huge number of stars. There are hundreds of times more of them per unit of space than near the Sun. Approximately ten billion of them form a galactic bar, also called a bar, of an unusual shape.
space nut
The study of the center of the system in the long-wavelength range made it possible to obtain a detailed infrared image. Our Galaxy, as it turned out, in the core has a structure resembling a peanut in a shell. This "nut" is the jumper, which includes more than 20 million red giants (bright, but less hot stars).
Spiral arms of the Milky Way diverge from the ends of the bar.
The work associated with the discovery of a “peanut” at the center of a star system not only shed light on what our galaxy is in terms of structure, but also helped to understand how it evolved. Initially, in the space of space there was an ordinary disk, in which a jumper formed over time. Under the influence of internal processes, the bar changed its shape and began to look like a walnut.
Our house on the space map
Active activity occurs both in the bar and in the spiral arms that our Galaxy has. They were named after the constellations where branches of the branches were discovered: the arms of Perseus, Cygnus, Centaurus, Sagittarius and Orion. Near the latter (at a distance of at least 28 thousand light years from the core) is the solar system. This area has certain characteristics, according to experts, that made possible the emergence of life on Earth.
The galaxy and our solar system rotate with it. The patterns of motion of the individual components do not coincide in this case. stars are sometimes part of the spiral branches, then separated from them. Only the luminaries lying on the boundary of the corotation circle do not make such "journeys". These include the Sun, protected from the powerful processes that are constantly taking place in the arms. Even a slight shift would negate all other advantages for the development of organisms on our planet.
Sky in diamonds
The sun is just one of many similar bodies that fill our galaxy. Stars, single or grouped, total more than 400 billion according to the latest data. The closest Proxima Centauri to us is part of a three-star system, along with the slightly more distant Alpha Centauri A and Alpha Centauri B. The brightest point in the night sky, Sirius A, is located in Its luminosity, according to various sources, exceeds the solar one by 17-23 times. Sirius is also not alone, he is accompanied by a satellite bearing a similar name, but labeled B.
Children often begin to get acquainted with what our Galaxy looks like by searching the sky for the North Star or Alpha Ursa Minor. It owes its popularity to its position above the North Pole of the Earth. In terms of luminosity, Polaris significantly exceeds Sirius (almost two thousand times brighter than the Sun), but it cannot dispute the rights of Alpha Canis Major to the title of the brightest due to its distance from Earth (estimated from 300 to 465 light years).
Types of luminaries
Stars differ not only in luminosity and distance from the observer. Each is assigned a certain value (the corresponding parameter of the Sun is taken as a unit), the degree of surface heating, color.
The most impressive sizes are supergiants. Neutron stars have the highest concentration of matter per unit volume. The color characteristic is inextricably linked with temperature:
- reds are the coldest;
- heating the surface to 6,000º, like that of the Sun, gives rise to a yellow tint;
- white and blue luminaries have a temperature of more than 10,000º.
It can change and reach a maximum shortly before its collapse. Supernova explosions make a huge contribution to understanding what our galaxy looks like. The photographs of this process taken by telescopes are amazing.
The data collected on their basis helped to reconstruct the process that led to the flare and to predict the fate of a number of cosmic bodies.
Future of the Milky Way
Our Galaxy and other galaxies are constantly in motion and interacting. Astronomers have found that the Milky Way has repeatedly swallowed up its neighbors. Similar processes are expected in the future. Over time, it will include the Magellanic Cloud and a number of dwarf systems. The most impressive event is expected in 3-5 billion years. This will be a collision with the only neighbor that is visible from Earth to the naked eye. As a result, the Milky Way will become an elliptical galaxy.
The endless expanses of space are amazing. It is difficult for the layman to realize the magnitude of not only the Milky Way or the entire Universe, but even the Earth. However, thanks to the achievements of science, we can imagine at least approximately what a part of the grandiose world we are.
