Description of the sky. Sky map

The description of the sky is a task that occupied the minds of many thinkers throughout history. The unification of disparate stars into figures, an understanding of the logic of the motion of the stars was necessary both for orientation on the terrain and for constructing a philosophical system explaining the laws and structure of the universe.

Combining the stars

The brain of a man is arranged in such a way that in any chaotic arrangement of objects he tries to see the logic behind the scattered and unconnected points to see the familiar silhouette. A map of the sky without this property would never have been born. People from the time of the appearance of the first civilizations were fascinated by the night sky and saw on it the familiar images: gods, heroes, objects. So the first constellations appeared. They were the union of neighboring lights in a certain figure. The constellations made it easier to memorize the location of the stars and, as a consequence, orient them on the terrain with their help.

Originally, the description of the starry sky was a set of constellations, often overlapping each other. Some of the stars could be related to two heavenly figures at once, and some areas remained deprived: because of a small number of stars in such territory they were not attached to any constellations.

Structuring

The description of the sky in the form of a map with the designation of constellations first appeared in the II century BC. E. He was made by Hipparchus of Nicea, one of the greatest Greek astronomers. His sky map contained 48 constellations and was supplemented with a catalog of 850 stars. Somewhat later, in the II century AD. This list was supplemented by Ptolemy. His famous work "Almagest" contained 1022 luminaries, broken into the same 48 constellations.

For a long time, until the beginning of the 17th century, Ptolemy's work, at least for European astronomy, remained the main, although throughout this period the list of constellations was supplemented with new ones. Celestial drawings arose mainly in those parts of the sky that were not available for observation by Ptolemy. In the 17th century Jan Hevelius, a Polish scientist, expanded the list of luminaries to 1533 and created his famous starry atlas "Uranographia" with beautiful drawings. He also added a few new constellations.

General Assembly of IAU

However, the description of the sky, made by Guevely, was not like the modern one. It began to acquire habitual features only in 1922, when I General Assembly of the International Astronomical Union (IAS) met. On it was approved a list of 88 constellations, which are used today. And the very meaning of the term "constellation" has changed. Today, it means not a certain number of luminaries that make up a particular figure, but a projection of a section of the sky with all the space objects on it. The boundaries of these sites underwent some changes and were finally approved in 1935.

Titles

The description of the night sky can not be done without knowledge of the names assigned to the constellations and individual luminaries. Latin names for celestial drawings are used in international practice. This allows one to understand each other by scientists from different countries. However, in textbooks and popular literature on astronomy, each nation has translations of accepted designations into its native language. It is often difficult to find an unambiguous equivalent. Therefore, for example, in our literature of different years, there are the Hair of Veronica and Berenice's Hair, Hounds Dogs and Greyhounds and so on.

As for the designations of stars, the brightest of them have their own names, most often of Arab origin. All without exception luminaries have a scientific designation. In addition, since the 16th century it has been customary to mark the stars of a particular heavenly figure with the letters of the Greek alphabet in accordance with their brightness: alpha is the leader in this parameter, beta takes second place and so on.

Two hemispheres

The heavenly sphere, like the earthly one, has its equator, which divides it into two parts. The sky of the Northern Hemisphere looks different than the southern part of the sphere: there are other luminaries here. On the line of the celestial equator are placed constellations, called equatorial. They are distinguished by the fact that they are available for observation practically anywhere in the world.

In the sky of the Northern Hemisphere, the situation is special for the Little Dipper. This small constellation is famous for its brightest point - the Polar Star, which always occupies the same place unlike other luminaries. It points north. In the Southern Hemisphere, there is no such bright "frozen" star. The role of the pointer to the pole is played by the Southern Cross constellation.

Zodiac

The description of the sky will be incomplete if we do not mention the constellations through which the visible path of all planets lies, as well as the Moon and the Sun. It's about the zodiac. Strictly speaking, it includes the not accepted 12, but 13 constellations. The "complementary" celestial pattern is the Ophiuchus, through which the center of the Sun passes from November 30 to December 17. It is interesting that the zodiacal circle in the sky as a whole strongly does not coincide with that adopted in astrology. The difference is not only the "superfluous" constellation, but also the time of occurrence of the Sun in each of the celestial drawings, as well as the duration of its stay in them. For example, in the constellation of Scorpio, our luminary is staying only a week from November 23 to 29.

Invisible

However, bright stars, close planets, as well as the Sun and the Moon are not all that can be seen in the sky. In the presence of a telescope, the observer's capabilities are greatly increased, and he has a chance to see clusters of light and planetary nebulae. Of course, the picture will not be the same as in the pictures of the famous "Hubble", but still look at it.

However, even without special equipment one can try to see distant neighboring galaxies. The Andromeda nebula is available for observation in the Northern Hemisphere, and Magellanic clouds, Big and Small, in the Southern.

The night sky beckons us with the brilliance of stars, cosmic mysteries and enigmas of universal scale. Anxious to solve them, people from ancient times have tried to facilitate their own memorization of the location of the stars, for which they united in heavenly drawings and were put on maps. With the increase of knowledge and the improvement of equipment, the latter were only refined, acquired a somewhat different structure. Today's description of the sky is more complicated and more accurate than what was at the time of Ptolemy, but we can say with certainty: and one hundred years later, children will begin to learn how to map star maps with the sky above their heads from the search for the most ancient heavenly drawings described by this wise Greek.