The night sky has interested man since ancient times. Behind each of his drawings is a story. Today, in the center of our attention, Libra is a constellation entering the zodiacal circle and containing many interesting objects.
Not the most noticeable
Many of the celestial drawings used in making horoscopes are quite clearly visible. The constellation of Libra is not included in their number. The luminaries that make up it are mostly dull. Two of its brightest points, alpha and beta, are related to the second stellar magnitude. The remaining luminaries are not clearly visible to an observer who is not armed with a telescope. The scales, we can say, are on the border between the bright zodiacal constellations of the Northern Hemisphere and the low-level constellations located in the South.
Part of Scorpio
Libra - a constellation, somewhat younger than the rest of his companions on the horoscope. Originally it was part of Scorpio, and only in the II century BC. e. became separate. In the period preceding it, the constellation was depicted either as an altar, then as a lamp, then as a scales proper. And these objects were placed in the Scorpion's claws. There is, however, the opinion that Libra was perceived as a separate constellation already in the ancient Sumerian civilization.
If we turn to antiquity, then this heavenly figure occurs in the pages of the famous treatise of Ptolemy "Almagest." There it is called "Claws of the Scorpion". In parallel with such a designation of a group of stars, there was also a separate name "Libra", which was part of the zodiac and came to Greece from Asia.
With the late appearance of this heavenly figure, the fact that he is the only inanimate object among astrological signs is also associated. The origin of Libra today is evidenced by the surviving names of its two bright stars, in translation meaning "southern and northern claw".
Libra is a sign of the zodiac, a constellation symbolizing harmony. Many legends of the ancient world are associated with it. In ancient Greece, the scales were considered an attribute of the goddess Themis, the wife of the thunderer Zeus, who was following the observance of justice in the world. Habitual today, her image includes a blindfold and a sword. It is believed that the last attribute is the result of the influence of Roman culture. The Greek Themis always held in her hand not a sword, but a scales and a cornucopia, in order to distribute rewards in justice. According to legend, Zeus immortalized the instrument of the spouse by placing it on the sky.
There is one more version of the origin of the constellation. In it, Libra is associated with the name of the Roman emperor Augustus the Just. After his death, the people, grateful to the ruler for his kindness, wished to place a constellation in his honor in heaven. For this, Scorpio was "cut down" and a symbol of equality and justice shone between him and the Virgin.
The stars in the Libra constellation is rather dim. However, there are remarkable objects. The brightest spot of the picture — "any El Shamali" ("the Northern claw"), or beta Weights. The star is a blue-white dwarf main sequence.
Beta Libra rotates 100 times faster than the Sun. A simple spectrum of the luminary allows scientists to actively use it to obtain information about the interstellar medium.
There is one mystery connected with the North claw. According to Ptolemy and Eratosthenes, Beta Libra was much brighter during the Antiquity period. Astronomers do not yet understand what causes the luminosity to decrease.
The second brightest point of this heavenly figure is Alpha Libra. It is called "Zuben Elgenubi" ("southern claw"). This is a multiple star system, the main component of which is a hot blue star. At a rather impressive distance from him is a satellite. It is defined as a yellowish star having its own movement, similar to its companion's analogous parameter. It is not completely clear to the end whether the luminaries are physically connected. The reason for doubting this is a huge distance (140 times farther than from the Sun to Pluto), their dividing. If the stars are connected, then the period of their circulation should exceed 200 thousand years.
A brighter component of the proposed system is also a double star. Its components are very close to each other, and therefore are hardly distinguishable. The distance between them is almost the same as the path from the Sun to Mercury.
Scales - a constellation that has more than one multiple system. The third brightest luminary consists of several components. This is the scale of Libra, also called "Zuben el Akrab" ("scorpion claw"). The brightest element of the system is the orange giant. Its diameter exceeds the analogous parameter of the Sun by 14 times. Gamma Libra is ahead of the center of our planetary system and by mass and luminosity (2.5 and 71 times, respectively). To date, the exact age of this space object remains a secret. According to various estimates, it ranges from 1 to 3.9 billion years.
The second companion is located a short distance from the first and somewhat dimmer than it. Presumably, it consists of two stars.
Libra is a constellation that includes the star, around which may rotate the planet, suitable for life. Is Gliese-581 or wolf-562 — red dwarf, remote from the Sun is 20.4 light years away. It is included in the list of the hundred nearest stars to us.
In 2010, it was believed that the Glise-581 planetary system contains 6 objects. Three of them, according to scientists. located in a zone suitable for life. Conditions on such planets are suitable for the existence of water in the liquid state and life in a form that is familiar to us. However, studies of subsequent years have yielded conflicting results. Some of them denied the probability of the existence of some planets, others - confirmed. Among astronomers to date there is no common opinion on this issue.
The constellation Libra is small and unobtrusive, but on its expanses there are a lot of interesting objects. He was looked at by ancient astronomers and compilers of horoscopes, he is not deprived of attention in our days. The constellation of Libra in the sky, therefore, is the object of many scientific studies.