What is called and what our Galaxy looks like. The name of the stars of our Galaxy

Starry sky from ancient times attracted the views of people. The best minds of all peoples tried to comprehend our place in the universe, to imagine and justify its structure. Scientific progress made it possible to proceed 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 schoolboy 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 prospective future is.

origin of name

The expression "Milky Way Galaxy", in fact, is a tautology. Galactikos in an approximate translation from Ancient Greek means "milky". So the inhabitants of the Peloponnese called the cluster of stars in the night sky, attributing its origin to the irascible Hera: the goddess did not want to feed Hercules, the illegitimate son of Zeus, and in anger sprinkled breast milk. The drops formed a starry path, visible on clear nights. Centuries later, scientists discovered that the observed luminaries are only an insignificant part of the existing celestial bodies. The space of the universe in which our planet is located, they gave the name of the Galaxy or the Milky Way system. After confirming the assumption of the existence and other similar formations in space, the first term became universal for them.

View from the inside

Scientific knowledge about the structure of the part of the universe, including the solar system, has taken little from the ancient Greeks. Understanding what our Galaxy looks like, has evolved from the spherical universe of Aristotle to modern theories in which there is a place for black holes and dark matter.

The fact that the Earth is an element of the Milky Way system imposes certain restrictions on those who are trying to find out what form our Galaxy has. For an unambiguous answer to this question, you need a view from the outside, and at a great distance from the object of observation. Now science is deprived of such an opportunity. A kind of substitute for an external observer is the collection of data on the structure of the Galaxy and its correlation with the parameters of other space systems available for study.

The collected information allows us to say with confidence that our Galaxy is in the form of a disk with a bulge in the middle and spiral arms diverging from the center. The latter contain the brightest stars of the system. The diameter of the disk is more than 100 thousand light years.

Structure

The center of the Galaxy is hidden by interstellar dust, making it difficult to study the system. Methods of radio astronomy help to cope with the problem. Waves of a certain length easily overcome any obstacles and make it possible to obtain such a desired image. Our Galaxy, according to the received data, has a non-uniform structure.

Conditionally, we can distinguish two related elements: the halo and the actual disk. The first subsystem has the following characteristics:

• In form this sphere;

• Its center is considered to be a bulge;
• The highest concentration of stars in the halo is characteristic for its mid-point, with density approaching to the edges, the density is greatly reduced;
• The rotation of this zone of the galaxy is rather slow;
• In the halo, there are mainly old stars with a relatively small mass;
• A considerable space of the subsystem is filled with dark matter.

The galactic disk with respect to the density of stars greatly exceeds the halo. In the arms there are young and even just emerging cosmic objects.

Center and core

The "heart" of the Milky Way is in the constellation of Sagittarius. Without studying it, it's hard to understand to the very end what our Galaxy is like. The name "core" in scientific works either refers only to the central region with a diameter of only a few parsecs, or it includes a bulge and a gas ring, which is considered the place where stars originate. Next, the first version of the term will be used.

The visible light penetrates into the center of the Milky Way: it collides with a large amount of cosmic dust hiding 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 prompted scientists to think that there is a black hole in the nucleus of the nucleus. Its mass is more than 2.5 million times the mass of the Sun. Around this object, according to researchers, another one, but less impressive in its parameters, rotates a black hole. Modern knowledge of the features of the structure of space suggest that such objects are in the central part of most galaxies.

Light and darkness

The combined effect of black holes on the motion of stars makes their own corrections to the way our Galaxy looks: it leads to specific changes in orbits that are uncharacteristic of cosmic bodies, for example, near the solar system. The study of these trajectories and the ratio of the velocities of motion with remoteness from the center of the Galaxy formed the basis of the now actively developing theory of dark matter. Her nature is still covered in mystery. The presence of dark matter, presumably making up the vast majority of the total matter in the universe, is recorded only from the effects of gravity just on the orbits.

If we scatter all the cosmic dust that hides the core from us, an amazing picture will open up to us. Despite the concentration of dark matter, this part of the universe is full of light, radiated by a huge number of stars. For one unit of space, they are hundreds of times larger than near the Sun. Approximately ten billion of them form a galactic bar, also called a jumper, of an unusual shape.

Space Nut

The study of the center of the system in the long-wave range made it possible to obtain a detailed infrared image. Our Galaxy, as it turned out, has a structure resembling a peanut in a shell. This "nutlet" is a jumper, which includes more than 20 million red giants (bright but less hot stars). From the ends of the bar, the spiral arms of the Milky Way diverge.

The work related to the discovery of "peanuts" in the center of the stellar system not only shed light on what our galaxy was in structure, but also helped to understand how it developed. Originally in space of space there was a usual disk in which in due course the crosspiece was formed. Under the influence of internal processes, the bar changed its shape and became like a nut.

Our house on the space map

The active formation of stars occurs both in the web and in the spiral arms, which our Galaxy possesses. The name was given to them by constellations, where sections of branches were found: sleeves of Perseus, Cygnus, Centauri, Sagittarius and Orion. Near the latter (at a distance of at least 28 thousand light-years from the core) and the solar system is located. This area has certain characteristics, according to experts, that made the emergence of life on Earth possible.

The galaxy and our solar system rotate with it. The patterns of motion of individual components do not coincide. A large number of stars at times that is part of the spiral branches, it separates from them. Only luminaries lying on the boundary of the corotation circle do not make such "trips". These include the sun, protected from powerful processes, constantly flowing in the sleeves. Even a small shift would negate all other advantages for the development of organisms on our planet.

The sky in diamonds

The sun is only one of many similar bodies, with which our Galaxy is full. The stars, single or grouped, total in excess of 400 billion according to the latest data. The nearest Proxima Centauri closest to us is a system of three stars, with slightly more distant Alpha Centauri A and Alpha Centauri B. The brightest point of the night sky, Sirius A, is in Constellation of the Great Dog. Its luminosity, according to different data, exceeds solar radiation by 17-23 times. Sirius is also not alone, he is accompanied by a satellite bearing the same name, but with the marking B.

Children often begin to get acquainted with what our Galaxy looks like, from a search in the sky of the Polar Star or the Alpha of the Little Dipper. Its popularity owes its position to the North Pole of the Earth. According to the luminosity of the Polar, it considerably exceeds Sirius (almost two thousand times brighter than the Sun), but it can not challenge the rights of Alpha of the Great Dog to the title of the brightest because of its remoteness from the Earth (estimated from 300 to 465 light-years).

Types of Luminaries

Stars differ not only in luminosity and remoteness from the observer. Each attribute is assigned a certain value (the corresponding parameter of the Sun is taken as the unit), the degree of surface heating, and the color.

The most impressive sizes are supergiants. The largest concentration of matter in a unit of volume is the neutron star. Color characteristics are inextricably linked with temperature:

• Reds are the coldest;
• Heating the surface to 6 000º, like the Sun, generates a yellow tint;
• White and blue luminaries have a temperature of more than 10 000º.

The luminosity of a star can vary and reach a maximum shortly before its collapse. Explosions of supernovae make a huge contribution to understanding how our Galaxy looks. Photos of this process, obtained by telescopes, amaze.
The data collected on their basis helped to restore the process that led to the outbreak, and to predict the fate of a number of cosmic bodies.

The Future of the Milky Way

Our Galaxy and other galaxies are constantly in motion and interact. Astronomers have established that the Milky Way repeatedly absorbed 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 Andromeda Nebula, the only neighbor that can be seen from the Earth with the naked eye. As a result, the Milky Way will become an elliptical galaxy.

The vast expanses of space amaze the imagination. It is difficult for an observer to realize the scale 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 some of what a grandiose world we are.