If you look at the sky on a clear summer night, your head can feel dizzy from a huge number of stars. The immense space of space above our heads has long attracted to itself, beckons with its secrets. For convenience, all the many stars are divided into constellations. When it is best to observe each of them depends on its location. If you rise from Earth into space, it will be impossible to meet there something resembling a heavenly drawing, familiar to us from childhood. The objects that make up the constellations, as it were, scatter and cease to be a single whole. This is because any constellation is a projection of a part of the sky on which all cosmic bodies are located, located here from the point of view of the observer. In fact, the distance between them can be thousands of light years.
One of the most famous celestial drawings is the constellation Cygnus. The flying bird pattern includes approximately 150 stars, several of which are among the brightest objects visible from Earth. Thanks to them, the constellation Cygnus is quite easy to find in the sky.
Observation
Since childhood, many amateur astronomers have known what the constellation Cygnus looks like. The stars that make up it are lined up in a cruciform shape resembling a large bird with an elongated neck and wings spread. The silhouette gives an unambiguous answer to the question of why the constellation Cygnus is so called.
The ideal time for observing it is in the summer. However, the Swan is noticeable throughout the year. It is easiest to recognize it from the many famous asterism (a characteristic group of bright stars) “Summer Triangle”. Part of it is a star in the constellation Cygnus called Deneb. Its other two peaks are Vega and Altair, one of the brightest points of the night sky. The constellation Cygnus for children and their parents who are fond of astronomy is also attractive because it stretches along the Milky Way.
History
The map of the sky we know today was not always like this. Partly because stars change their position over time. This is especially noticeable in the case of cosmic bodies closest to us. For example, in the place of the Polar Star, once a very long time ago, more than 17 thousand years ago, Deneb was already mentioned above.
Another reason for the mismatch of the celestial maps of the present and the past is the combination of different stars in groups. One of the first descriptions of the constellations dates back to 275 BC. e. It was created by the Greek poet Arat. This work was then, after four centuries, revised by Ptolemy. His Almagest contains a list of 48 constellations. One of them (Argo) was subsequently divided into three separate ones (Kiel, Korma, Sail, Compass), the rest have retained their name until now.
Today, scientists distinguish 88 constellations. The swan belongs to the ancients mentioned in the list of Ptolemy. True, at that time he was known as the Bird. The history of the constellation Cygnus also includes the mention in the writings of the astronomer Eudoxus of Cnidus, dating from the fourth century BC. The names of the luminaries in the composition of the Cygnus recall the period when most sciences, including astronomy, developed in the East, in Arab countries.
Star bridge
The brightest star in the constellation Cygnus is Deneb, or Alpha Cygnus. Translated from Arabic, its name means "tail." The designation is consistent with its location. Deneb adorns the constellation Cygnus (the diagram below) in exactly the part where the bird’s tail is located. The object belongs to the white supergiants. The impressiveness of a star is well recognized when compared with our star. So, the mass of Deneb is equal to twenty solar. According to various estimates, the distance from Earth to Deneb is from 1.55 to 2.6 thousand light years. At the same time, it is clearly visible in the sky, because its luminosity is more than 270 thousand times greater than the solar.
As already mentioned, Deneb enters the Summer Triangle. A beautiful Chinese legend is associated with the stars at its peaks, in which Deneb appears as a bridge between the lovers represented in the sky by Vega and Altair. According to legend, it occurs once a year. Lovers can spend this night together. Then they will again have to part for another year.
Crown
The opposite to the Deneb point of the constellation Cygnus is Albireo (beta Cygnus). She crowns the head of a bird. In order to understand what the constellation Cygnus looks like and where it is located, it is enough to find these two bright points. Albireo, like Deneb, can be seen with the naked eye. Those who decide to study it with a telescope will open an even more interesting picture. Albireo is a two-star system. The largest of them, Albireo A, is an orange giant. His companion is a blue star belonging to the Main sequence, Albireo B. The name of the star in Arabic translates as "chicken beak."
Gamma and Swan Delta
The central point of the constellation is Sadr, which means "chest." This is the second brightest star. Sadr (Swan gamma) is a supergiant belonging to the spectral class F8, with a pulsation period of 74 days. It is 12 times the mass of the sun.
Following the Sadr in luminosity is the Swan Delta. It is a binary star system located at a distance of 170 light years from Earth. Distinguishing her is much more difficult than Albireo. The delta includes two stars located close enough, with a circulation period of 537 years. The first is a blue-white giant with a luminosity significantly higher than solar. His neighbor is a yellow-white star, less impressive in all respects.
Reference
Epsilon Swan or Jenah - a significant point not only on the map of the starry sky, but also in astronomical calculations. It is located 73 light-years from Earth. In translation, Jenah, or Hyena, means “wing”: the name gives an exhaustive description of its position in the constellation. It shines 62 times brighter than the sun.
A special role of Jenah in science is that its spectrum is a standard for the classification of other stars. In addition, it was on this space object in 1846 that Neptune was discovered.
North cross
The constellation Cygnus for children and adults is known for another asterism called the Northern Cross. It is formed by five described stars. At the base is Albireo, the apex is designated Deneb, in the center of asterism is Sadr, and on the sides are Jenah and Swan Delta. These are the brightest points that make up the Swan. The constellation (the photo makes it clear well) can not boast of a bright glow of its other elements. Of course, five stars do not exhaust the interesting objects of a celestial bird. However, it is the Northern Cross that makes the constellation Cygnus so noticeable. How to find it, they usually don’t even think about it: asterism is known to almost everyone.
Other “population”
Another interesting object of the constellation is 61 Cygnus, a binary star system. It is made up of two orange dwarfs. Like Albireo, the system is visible from Earth and is available for study. Its uniqueness is that 61 Swans are among the stars closest to the Sun (the distance from our star is 11.36 light years). In addition, it has a significant own movement and belongs to a small number of similar objects visible from the Earth. 61 Swans are famous due to the prevailing opinion in astronomy of the middle of the last century that it has a planetary system. New data obtained since then do not confirm the hypothesis, but the star continues to be in the center of attention of many scientists.
Another object of great interest is the Black Swan X-1 hole, located near 61 Swans. This is the brightest source of x-rays in the constellation. Swan X-1 is identified with two objects: one of them is a bright blue star, the other is its companion, inaccessible to observation. Radiation occurs due to the flow of substance of a blue star into a black hole. In the process of moving it heats up to huge temperatures, and part of it is thrown into space in the form of two jets directed in different directions from the object. The status of the black hole Swan X-1 received in the 70s of the last century.
Nebulae
Stars are not the only objects included in the constellation Cygnus. Its outline also includes a dark area called the Northern Coal Sack. This is an interstellar cloud of dust and gas located quite close to our Galaxy. There is also a number of nebulae. The complex of space objects, designated as the Veil or Network (NGC 6960 and NGC 6992), are the consequences of a supernova explosion that occurred 40,000 years ago. At the western edge of the Veil is the Witch's Broom Nebula, striking in its beauty in pictures taken with telescopes.
The brightest star in the constellation Cygnus, Deneb, boasts a neighborhood with two nebulae: North America (NGC 7000) and Pelican (IC 5070). The first in its outlines very much resembles the continent of the same name. Together with the Pelican Nebula, they extend for 50 light years. From the Earth they can be seen with the naked eye, provided that the observer is in an area remote from urban and any other artificial lighting. They will appear in the form of a small vague spot in the northeast of the brightest star that Swan possesses. The constellation, the photo of which, along with all the nebulae will be very interesting to see absolutely everyone, is famous not only for its bright stars and other neighboring space objects. Thus, the image of a noble bird and the history of the appearance of the constellation are reflected in ancient mythology.
Orpheus and lyre
The swan is the hero of many legends and tales. Both in our and in foreign culture, this bird was a symbol of beauty, purity of soul, art. Some myths also tell about how the constellation Cygnus appeared in the sky. The legend, cited for children in history books for high school, is associated with the ancient Greek singer Orpheus. According to her, when he set off to return beloved Eurydice from the kingdom of the dead, he violated the prohibition to turn around on the way back and forever lost the opportunity to reunite with his beloved. Saddened, he wandered around the world for several years, remaining faithful to Eurydice and not allowing other girls to come to him, for which he was known as a misogynist. Once, on the banks of the Coat of Arms, he met a group of Bacchanas, admirers of Dionysus. Recognizing Orpheus, they burned with anger and tore him apart, throwing the singer’s lyre and his head into the water. The gods of Olympus did not remain indifferent to the hero, who admired them with his talent. According to one version of the myth, the soul of Orpheus and his lyre were elevated to heaven. So there were the constellations Lyra and Swan, located next to each other.
Phaeton
There are several more myths explaining why today we can consider the constellation Cygnus. The legend tells of the son of Helios, the sun god, Phaeton. Mortal, he wanted to prove his origin and begged his father to let him ride on a solar chariot through the sky. Helios agreed. The proud Phaeton was unable to cope with the hot horses and fell out of the chariot into the river. On earth, his remains have long been sought by Cycnus, a loyal friend. The gods, seeing how sad he was, turned him into a swan. In this guise, he lived by the water. Wishing to perpetuate disinterested friendship, Zeus placed the constellation Cygnus in the sky. The legend, in the center of which is a hero named Kikn, is found in other variations. His name is translated from Greek as “swan”.
Options for the origin and death of Kikna
The hero, later turned into a noble bird, in various myths was the son of one or another god. Born from Apollo, Kikn drowned in a lake, which was later called Kikney. As the son of Poseidon and Kaliki, he is found on the pages of the legends of the Trojan War. According to legend, Achilles killed him, and his father turned Kikna into a swan. The third option tells that his parents were Ares, the god of war, and Pelopia. The legend tells about the excellent ability of Kikna to drive a chariot. He loved to challenge all guests who visited the house to the competition. The victory invariably remained with Kiknom until Hercules became his rival. He surpassed the son of Ares and wounded the god of war himself. Zeus was forced to intervene in the situation. As a result, Kikn was turned into a swan.
Crucifix
Later eras filled the meaning of the constellation Cygnus. Its outline on maps of the 17th century and later was often replaced by the image of the crucified Christ. Not the last role in this identification was played by the Northern Cross, which was clearly visible from Earth. Its correlation with the crucifix was also found in earlier documents. The treatise of St. Gregory of Tours, dated 592, describes the Great Cross with an indication of its relationship to the constellation Cygnus. According to the saint, it was located between the letters alpha and omega, "written" by the stars of Dolphin and Lyra, respectively. Similar symbols were correlated with a quote from the revelation of John, in which the risen Christ calls himself Alpha and Omega, beginning and end.
Interestingly, the image of the crucifixion again sends us to Orpheus. According to some scholars, the Christian Romans at the dawn of the new faith borrowed the symbol of the crucified god from the pagans, who depicted Orpheus. This assumption once again links the constellation Cygnus, the myth of the singer, and the biblical legend.
Starry space, striking in its beauty and invariably attracting not only looks, but also people's thoughts, in ancient times forced the wise to seek an explanation for all this magnificence. The constellation Cygnus is a vivid example of how the need to comprehend an inaccessible cosmos using artistic means was expressed in poetry and legends. Perhaps, if the views of the ancients were not stated in legends and myths, we would not have known about them even half of what is known today.
Modern people are also not without a desire to understand what is behind the many bright points of the night sky. Behind rigorous scientific calculations one can see the dream of comprehending the mystery of the cosmos, of knowing its laws and of an intuitive understanding of the impossibility of embodying all its imperfection in the human mind. The images of the Hubble telescope and its "colleagues" clearly show how close to the truth were the ancient poets in understanding the beauty that stretched over our heads. Looking at the photographs, it is easy to believe that among the sparkling magnificence of stars and nebulae any gods would not disdain to live.