Since ancient times the people considered the night sky. They tried to solve the mystery of a light strip which was thrown through a star firmament. Gradually, with development of science, this secret was solved. Now it became known how our galaxy the Milky Way is arranged.
If to look at the transparent sky in cloudless night, then to a look the amazing show will open. Among billions of sparkling stars, through a night firmament, there passes the white fog. Her name the Milky Way, at the translation into Greek, it will sound as "Galaxy".
History of opening of the Milky Way
Residents of Ancient Greece trusted in myths about gods of the Olympus. They considered that the cloud in the night sky, was formed when the goddess Hera fed little Heracles and accidentally spilled milk.
In 1610 Galileo Galilei (1564-1642) created the telescope and could consider a heavenly fog. It turned out that our Milky Way is built from a set of stars and dark clouds which with the naked eye cannot be considered.
In the 18th century William Gershel (1738-1822) could systematize researches of the Milky Way. He found out that in a vacuum there is a big circle, now it is called the galactic equator. This circle divides space into two identical parts and is built from a huge number of star clusters. The closer there is a site of the sky to the equator, the more it is possible to find on it stars. Our native galaxy also lives in this circle. From these observations Gershel drew a conclusion that heavenly objects which we see make flattened to the equator, a star system.
Immanuel Kant (1724-1804) the first made the assumption that it is possible to find some more galaxies similar to our Milky Way in space. But in 1920, disputes on uniqueness of the galaxy continued. Edwin Hubble and Ernest Epik could prove an assumption of the philosopher. They measured distance to other fogs, and as a result decided that their arrangement is too distant, and they are not a part of the Milky Way.
Form of our galaxy
The Maiden's supercluster which is built from a set of different galaxies includes the Milky Way and other fogs. Just as all astronomical objects, our galaxy turns round its pivot-center and flies in space.
At the movement on the Universe, galaxies face, and there is an absorption of small fogs by larger. If the sizes at two faced galaxies identical, then begin to be formed new stars.
There is a hypothesis that the Milky Way at first will face Big Magellanic the Cloud and will incorporate it. Then will face Andromeda, and then there will be an absorption of our galaxy. These processes will create new constellations, and the solar system can drop out in huge intergalactic space. But there will be these collisions only through 2 — 4 billion years.
The age of our galaxy is equal to 13 billion years. Throughout this period of time, more than 1000 gas clouds and different fogs in which there are about 300 billion stars were formed.
The size of diameter of a disk at the Milky Way is 30 thousand parsecs, and thickness is equal to 1 thousand light years (1 light year is equal to 10 trillion km). It is difficult to determine the mass of the galaxy, the main weight in it is made by not studied, dark matter, it is not influenced by electromagnetic radiation. She creates Galo which is concentrated at the center.
Structure of the Milky Way
If to survey on our galaxy directly from space, then it is easy to notice that it looks as a flat round surface.
Kernel
In a kernel there is a thickening which cross size is equal to 8 thousand parsecs. There the source of non-thermal radiation with a high density of energy is located. In visible light its temperature is 10 million degrees.
In galaxy heart the astronomers found the huge size, a black hole. The scientific world made a hypothesis that around it one more small black hole moves. Its cycle time lasts hundred years. Except it there are some more thousands of small black holes. There is a hypothesis that generally all galaxies of the Universe contain a black hole in the center.
Gravitational impact which is made by black holes on the next stars forces them to move on peculiar trajectories. Directly in the center of the galaxy there is a huge number of stars. All these stars old or dying.
Crossing point
In the central part it is possible to see a crossing point which size is equal to 27 thousand light years. It is at an angle 44 degrees to the imagined line laid between our star and a galactic kernel. In its structure it is possible to find about 22 million growing old stars. The crossing point is surrounded by a gas ring, in it new stars are formed.
Spiral sleeves
Directly behind a gas ring five huge spiral sleeves were located. Their size is about 4 thousand a parsec. Each sleeve has the name:
- Lebed's sleeve.
- Perseus's sleeve.
- Sleeve of Orion.
- Sleeve of the Sagittarius.
- Centaur sleeve.
Our solar system can be found in a sleeve of Orion, from its internal part. Sleeves consist of molecular gas, dust and stars. Gas is located very unevenly and therefore includes correction in rules by which the galaxy rotates, creating a certain error.
Disk and crown
In a form our galaxy is a huge disk. In its structure it is possible to find gas fogs, cosmic dust and a set of stars. The general diameter of this disk is about 100 thousand light years. Near a disk surface, new stars and gas clouds were located. In a disk and also in spiral sleeves there is an active formation of stars.
On an outer edge the crown is located. It extends for borders of our galaxy on the whole 10 light years and is similar to spherical Galo. Unlike the high speed of the movement of a disk, rotation of a crown happens very slowly.
She is brought together from a congestion of hot gas, the small growing old stars, and small galaxies. They randomly move around the center for ellipsoidal orbits. Researchers of space consider what Galo appeared as a result of grab of smaller galaxies. By calculations, a crown of one age with the Milky Way and therefore the birth of stars in it stopped.
Address of the solar system
People can observe the Milky Way in the transparent dark sky from any point of Earth. It looks as the wide strip similar to a white translucent cloud. As the solar system was located on an internal part of a sleeve of Orion, people can see only a small part of the galaxy.
The sun lodged at the most extreme part of a disk. The distance from our star to a kernel of the galaxy is equal to 28 thousand light years. In order that the Sun could take one detour, 200 million years will be required. For that time which passed from the moment of the star birth the Sun flew about the galaxy about thirty times.
The mother Earth lives in the unique place where the angular speed of rotation of stars, coincides with angular rotation of spiral sleeves. As a result of such interaction, stars do not leave a sleeve or never enter them.
Such type of rotation is not typical for the galaxy. Usually, spiral sleeves have constant angular speed and rotate as needles in a bicycle wheel. At the same time stars move with absolutely other speed. As a result of this discrepancy of a star move, flying in spiral sleeves, taking off from them.
This place is called a korotatsionny circle or "a life belt". Scientists consider that only in a korotation zone (at the translation from English this word sounds, as a zone of joint rotation) where there are not enough stars, it is possible to find manned planets. Spiral sleeves have very high radiation, and it is impossible to live in such conditions. Proceeding from this hypothesis, systems on which life can arise it is not enough.