Star triangle in the autumn sky. Astronomical experiments Autumn triangle in the sky

Summer nights are short in mid-latitudes... For astronomy lovers, there is a temporary lull in observations - the sky is too bright even at midnight, and in the north, at the latitude of St. Petersburg, white nights come at all. But the clear and warm weather allows you to comfortably sit at the telescope. Most of the sights described here are visible in a relatively bright sky, and only to observe some extended nebulae is it worth waiting for the dark and moonless August sky.

At first glance, a huge triangle with a top lowered down, formed by the bright stars of the constellations Cygnus (Deneb), Lyra (Vega) and Eagle (Altair), stands out in the summer sky, but not only these three constellations deserve attention - in the vicinity of this "Summer Triangle" there are many objects that are diverse in nature and most interesting to observe.

Swan

Long ago, the famous Spartan hero Tyndareus was expelled from his native country by his brother Hippokont. For many years he wandered around Greece, until he found refuge in Aetolia with King Testius, who became so friendly with him that he gave him his beautiful, like a goddess, daughter Leda as his wife. A few years later, Hercules killed the treacherous Hippokont, and Tyndareus and Leda returned to their native Spatra.

The fame of the beauty and charm of Leda spread throughout Greece. Zeus saw her once and immediately began to think about a way to meet the beauty so that his jealous wife Hera would not know about it. He turned into a snow-white swan and descended from Mount Olympus to Sparta, to Leda.

Every night, Leda received the Swan - the almighty Zeus. From him, she had two children - a beautiful daughter, Helen, who later became the cause of the Trojan War, and a son, Polydeuces, whom Zeus bestowed with immortality. From Tyndareus, Leda also gave birth to two children - a daughter, Clytemnestra, and a son, Castor.

In the sky, the constellation Cygnus personifies Zeus, who, turning into a bird, flies to his beloved Leda.

Cygnus is one of those constellations whose figures are easily recognizable and correspond to their names. Bright stars form a huge cross, on top of which (this is the tail of a bird) Deneb sparkles, and a long neck is turned to the earth and is marked with the star Albireo (β Cygnus) in the head. By the way, Albireo (in the photo on the right) is one of the most beautiful double stars - it is easy to see even with binoculars, an orange-yellow main star 3.4 m and a bluish companion 5.4 m, which often looks greenish due to the peculiarities of our vision.

Another bright binary, δ Cygnus, is more difficult to observe - the distance from the main star 3.4 m to the satellite 6.4 m is 2.1 "

The main star of the constellation, Deneb, also deserves attention - it is a hot white supergiant, about one and a half thousand light-years distant from us, its luminosity is at least 60 thousand times greater than the solar one, and its diameter is comparable to the size of the earth's orbit. All these figures are approximate, since it is very difficult to accurately measure such a large distance to a star, but Deneb is definitely one of the most impressive stars in our sky.

The constellation Cygnus lies in one of the brightest parts of the Milky Way, where it splits into two wide arms. This separation is not caused by the actual difference in the density of the stars, but by accumulations of light-absorbing dust in the plane of the Milky Way. Gas-dust nebulae are perhaps the main attractions of the constellation.

To the left of Deneb is a complex of hydrogen nebulae, which, for their very characteristic shape, are named "North America" (NGC7000) and "Pelican" (IC5070). Their glow is excited by the radiation of Deneb, although it is located not so close to them - at least 50 light years!

Constellation Cygnus. (mouse over an object to see its photo)

Another group of nebulae located under the left wing of Cygnus is Veil (NGC6960,NGC6992), which has a very interesting fibrous structure. Unfortunately, these nebulae are very difficult to observe - only in a dark sky can you see their brightest parts. It is better to use binoculars or a telescope with a minimum magnification to search for them. Even weaker, but very extended clouds surround the stars γ and η Cygnus. On the line connecting these stars, a little closer to γ Cygnus, there is an interesting nebula NGC6888 "Sickle" or "Crescent", visually it is almost indistinguishable, but it looks very impressive in photographs.

Of course, the Cygnus constellation is also rich in other remarkable objects that are much easier to observe. There are many open star clusters in the Milky Way band, the most visible of which, M39, is clearly visible with any binoculars. This cluster does not have a large number of stars - there are only about two dozen of them, but all of them are fairly bright white giants and the cluster looks very impressive thanks to this. Another cluster included in the Messier catalog, M29, located a little south of γ Cygnus, looks rather nondescript - there are dozens of them here.

Pay attention to the dim (5.2 m) orange star marked as 61 Cygnus. This is a double star that is easily observed in the most modest telescopes. But the main thing is that this is one of the first stars for which the distance was determined in 1837 - it turned out to be just over 11 light years, that is, it is one of the stars closest to us.

Lyra

In Thrace, the river god Eagra and the muse Calliope had a son, Orpheus. From childhood, he showed a desire for music, and his mother gave him to study with the wise centaur Chiron, the teacher of such famous heroes as Hercules and Jason. Orpheus quickly mastered everything that his mentor taught him, but most of all he was attracted to music and he practiced playing the lyre for hours under the guidance of Chiron. Soon he mastered the art of singing and playing so much that he surpassed his teacher in this.

The fame of the great singer spread all over the earth, people were fascinated by his songs, the trees bowed their branches and stopped making noise, wild animals and birds, enchanted by wondrous music, gathered around him...

Soon Orpheus married the nymph Eurydice, whom he loved passionately. But their happiness was short-lived - soon Eurydice died, bitten by a poisonous snake. Orpheus was inconsolable, nothing could make him forget about his beloved, every day his despair grew stronger ... Finally, he decided to go down to the underworld and beg Hades to return Eurydice to him.

Orpheus descended through the bottomless abyss to the underground river Styx, but the carrier Charon refused to transport him to the kingdom of shadows: his business is to transport only the souls of the dead to the other side of the Styx, to the kingdom of Hades.

Then Orpheus took his golden lyre, sat down on the bank and began to play. Divine sounds resounded over the black waters of the Styx. Even Charon was so fascinated by them that he did not notice how Orpheus climbed into his boat and drove it to the other side.

Appearing before Hades, Orpheus continued to sing and play the lyre, in this song he expressed all the pain for his beloved Eurydice. And this music and song was so beautiful that Hades was moved and agreed to return Eurydice to the kingdom of the living, but with one condition: Orpheus must follow the god Hermes, who will lead him out of the underworld, and Eurydice will follow Orpheus, but Orpheus cannot look back Eurydice, otherwise she will forever remain in the realm of the dead.

Orpheus accepted this condition and they began the difficult journey up the narrow and steep path to the Earth, bathed in the rays of Helios. But no matter how Orpheus listened, he did not hear the steps of his beloved behind him. Forgetting that Eurydice was still only a shadow, forgetting the condition, Orpheus could not stand the uncertainty and looked back just before the exit. He managed to see the shadow of Eurydice, forever dissolved in the darkness of the underworld...

Having lost his beloved for the second time, Orpheus did not want to return to Earth, he again descended into the underworld, but this time even his songs did not touch the icy heart of Charon...

Soon Orpheus died, and in the underworld of Hades Eurydice met her lover and nothing could separate them. And the gods placed the golden lyre of Orpheus in heaven in memory of the great singer and the power of human love...

The main star of this small constellation is Vega, one of the brightest stars in the sky. This is a hot white star, about 2 times larger than the Sun, the visibility in our sky is explained by its rather close position to us, about 25 light-years to Vega. By the way, the distance to it was determined by Struve in the same 1837, when Bessel measured the distance to 61 Cygnus. In general, Vega occupies a special place in the history of astronomy - this is the first star that was photographed (1850), a photograph of the star's spectrum was also obtained for the first time for Vega (1872), it was also chosen as a brightness standard - as a zero star quantities.

Pay attention to the star ε Lyra a little east of Vega - even with the naked eye you can see that this is a double star - the distance between the components is about 3.5 ", but the telescope shows that each of the stars that make up this pair, in turn, is a double star, the distance between them is much smaller - 2.3 "and 2.8", so this system is very convenient for assessing the quality of small amateur telescopes. All components of this 4x system are white stars, very similar in their characteristics.

Probably the most famous landmark of the constellation can be considered the famous planetary nebula "Ring" M57, located about 1/3 of the distance from β to γ Lyra, its photograph is almost certainly found in any popular science book on astronomy and in any textbook. Even in a small telescope at a magnification of about 100x, the annular, slightly elongated shape of the nebula is clearly visible, and photographs show very interesting details of its structure. It can be seen that the outer part of the ring is red, the inner is greenish-blue, this is due to the difference in the chemical composition of different parts of the nebula - in the outer part, the emission of hydrogen is most noticeable, in the inner - ionized oxygen. Please note that the inner, dark part of the ring is much lighter than the surrounding background. This means that the nebula is not a flat ring, but a thick-walled sphere. The glow of this giant gaseous sphere (and its diameter is about 1/2 of a light year) is caused by the re-emission of energy from a very hot white dwarf located in the center of the nebula.

Constellation Lyra. (mouse over an object to see its photo)

Approximately in the middle between γ Lyra and β Cygnus, you can find the globular cluster M56, but it is rather nondescript and in small telescopes it is practically not resolved into individual stars.

There are several wonderful variable stars in the constellation Lyra. RR Lyrae is a short-period Cepheid, such stars are allocated to a separate class, which is named after this variable. β Lyrae, a very unusual eclipsing variable star, deserves special mention. Its components are so close to each other that they have an elongated ellipsoidal shape; moreover, they are immersed in a common gas envelope. The period of this variable is 12.9 days, and the brightness smoothly changes from 3.4 m to 4.3 m with a noticeable intermediate minimum of 3.8 m .

Eagle

When Zeus matured and began to fight with his father Kronos for power over Heaven and Earth, only one of the Titans - Prometheus supported him. Therefore, Prometheus was allowed to live on Olympus with other gods, while the rest of the titans were cast into gloomy Tartarus.

But the idle life on Olympus did not attract Prometheus. He saw how hard and unhappy the life of people who did not yet know fire, who froze in cold caves and died of hunger and disease. Prometheus thought that people would not be so unhappy if they had fire, but Zeus strictly forbade giving it to people.

Prometheus disobeyed the will of the great Zeus - he stole fire from the forge of Hephaestus and brought it to people. He taught them how to cook food, tame animals, smelt and process metals.

Zeus was angry when he saw what Prometheus had done. By his order, Prometheus was seized, chained in heavy chains and taken to the very ends of the earth, to the Caucasus, where they were chained to a lonely rock near the seashore. And every day an eagle flew to the rock with Prometheus to tear the chest of the titan with its iron claws and beak and peck at his liver. During the night, the wounds of Prometheus healed, and in the morning the eagle flew in again - the messenger of Zeus, and this torture continued for thousands of years.

But a hero was born on Earth, who was destined to free Prometheus. This hero, mighty as the gods was Hercules. He traveled many countries, accomplished many feats and, finally, came to this far end of the Earth. Standing in front of a huge rock, he looked at the chained Prometheus and listened to his story. Suddenly, the sound of wings was heard and a huge eagle appeared above, it circled over the rock, ready to pounce on Prometheus. Then Hercules took his bow, put an arrow in and prayed to Apollo to direct it exactly to the target, lowered the bowstring. The eagle, pierced by the hero's arrow, fell into the sea at the very rock...

Thus ended the torment of Prometheus, he was forgiven by Zeus and set foot on Earth free, embracing Hercules, whom he had been waiting for for thousands of years.

In the sky, a predatory Eagle and an Arrow fired by Hercules remained a reminder of this. There is not only a constellation in the sky dedicated to Prometheus, but people will never forget the one who gave them fire and knowledge, with which they fight against the power of the gods.

Eagle constellation.

The constellation Eagle, despite its rather large size and location in the Milky Way band, is extremely poor in interesting objects. The main star of the constellation - Altair, is quite an ordinary star, somewhat larger than the Sun, stands out only due to its relatively small distance - about 17 light years. Of interest is the variable η Eagle located south of Altair, an ordinary Cepheid with a period of about 7.2 days and a change in brightness from 3.5 m to 4.4 m. Its variability was discovered by Pigott a year earlier than that of δ Cephei, which for some reason gave its name to this class of variable stars.

Of course, there are several open and globular clusters, planetary nebulae in the constellation, but these objects are unremarkable or very difficult for amateur observations.

In the southwestern part of the constellation there is a funny asterism "Hanger" (Cr399) - several stars of 5-6 magnitude form an almost straight line with a hook in the middle. This cluster is quite large, clearly visible with binoculars and a small telescope at minimum magnification.

Arrow

This is a very small but ancient constellation, its characteristic figure of only 4 noticeable stars really resembles a flying arrow. Perhaps the only interesting object in this constellation is the globular cluster M71, located just below the middle of the "shaft" of the arrow. The cluster looks rather nondescript, but this is its main feature - it is "the most scattered of globular clusters", for a long time it was even considered scattered. By the way, the stars δ and ζ of this constellation are an excellent indicator for searching for the planetary nebula M27.

Northern hemisphere celestial sphere, well observed in summer and autumn in the middle latitudes of the northern hemisphere. It is a triangle of three bright stars: Vega (α Lyra), Deneb (α Cygnus) and Altair (α Eagle).

At low latitudes of the southern hemisphere, asterism is observed in winter and spring in the northern part of the sky low above the horizon. At latitudes higher than 50°S, only Altair is visible.

Variants of the name: "autumn-summer", "summer", "big summer" and "autumn triangle".

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An excerpt characterizing the Summer-Autumn Triangle

Esclarmonde burst into tears... She so wanted to look courageous and strong!.. But her fragile and affectionate woman's heart let her down... She didn't want them to leave!.. She didn't even have time to recognize her little Vidomir! It was much more painful than she naively imagined. It was a pain from which there was no escape. She was in so much pain!!!
Finally, kissing her little son for the last time, she let them go into the unknown... They left to survive. And she stayed to die... The world was cold and unfair. And there was no room in it even for Love ...
Wrapped in warm blankets, the four stern men stepped out into the night. These were her friends - Perfect: Hugo (Hugo), Amiel (Amiel), Poitevin (Poitevin) and Svetozar (which is not mentioned in any of the original manuscripts, everywhere it simply says that the name of the fourth Perfect remained unknown). Esclarmonde tried to go after them... Her mother would not let her go. It no longer made sense - the night was dark, and the daughter would only interfere with those leaving.

Such was their fate, and it was necessary to meet it with your head held high. As difficult as it may be...
The descent down which the four Perfects left was very dangerous. The rock was slippery and almost vertical.

So nature arranged that in the northern and middle latitudes of Russia, summer nights are bright. Throughout June and most of July, the evening astronomical twilight merges with the morning. At the latitude of St. Petersburg, even they do not advance, and beyond the Arctic Circle, the Sun does not set beyond the horizon at all. And we can fully enjoy the constellations of the summer sky only on dark August nights.

But there is a special charm in the bright June skies.

I have a memory of my early childhood... I am six or seven years old. Village street, bench near the house. Ten or eleven o'clock in the evening. My grandmother and I came for milk and are waiting for the hostess to milk the cow. In anticipation of a mug of fresh milk, I dangle my legs and stare around - including up to the sky. And there - one after another, the stars hatch. One... two... three bright ones! And every day I notice that they are the first to appear! So Vega, Deneb and Altair, the main stars of the constellations Lyra, Cygnus and Eagle, entering the so-called Summer-autumn triangle, entered my life (although I did not know their names). True, this name, like many "seasonal" delimitations of stars and constellations, is very arbitrary. In fact, these three stars can be observed, for example, at the latitude of Moscow, on every clear night. Vega and Deneb are non-setting stars, and Altair, due to the fact that its lower climax at night falls in the winter months, from December to February has time to visit the western part of the sky in the evening, and in the morning, also against the background of twilight, rise in the east. (By the way, this advantage distinguishes Altair from such stars as Procyon and Betelgeuse, which also lie just north of the celestial equator, like him, but due to the fact that the lower climax at night they occur in short summer nights, and the Sun, which is to the north in declination, ahead of them with its sunrise, visible in the dark sky for only six months). Well, and the summer months - sorry for the involuntary tautology - the "finest hour" of these luminaries.

On dark August nights, a majestic spectacle is clearly visible - the Milky Way, a foggy stripe crossing the sky exactly in half - from north to south. One of its brightest parts passes just through the Summer-autumn triangle. Against the background of a silvery mist of star placers of our Galaxy, the outlines of the constellations - Lyra, Cygnus and Eagle look even more beautiful. Each of them is remarkable in its own way.

Swan - the very sight of this constellation resembles a flying bird, spreading its wings. The constellation was singled out in ancient times, but the ancient Greeks called it simply "Bird", and the Arabs (just don't laugh!) - "Chicken". Much later, the constellation received its current name, which was then tied to the ancient Greek myth about how Zeus appeared to Leda in the guise of a swan. This story has been the subject of works of art many times.

In the region of the constellation Cygnus, the Milky Way is divided into two arms. This is an apparent picture - in fact, it is blocked from us by a layer of interstellar dust. In the constellation Cygnus there is a bright open cluster M39, the famous complex of gas and dust nebulae, the beautiful double star Albireo (Beta Cygnus), as well as the long-period variable star Chi Cygni - one of the first discovered stars of this class (1687). Its brightness varies from 2 m to 14 m with a period of 407 days. The main star of the constellation is Deneb. Translated from Arabic, it means "tail" - and indeed, the star represents the tail of a swan. Deneb is a white supergiant, shining 6000 times brighter than the Sun. In diameter, it is 35 times larger than the Sun, but due to its large distance (170 parsecs, or more than 550 light years), it is visible from Earth only as a 1 m, 3 star. Vega and Altair are much closer to us. They are 26 and 16 light years away. And it is precisely because of its proximity to us that Vega is the brightest star in the Northern Hemisphere of the sky. It has zero magnitude. Altair - star 0m,8

The constellation Lyra is characterized by a small rhombus of 3 m - 4 m stars near Vega. Between the two lower stars of this rhombus is the famous planetary nebula "Ring" - M57 (see photo on the left). But one of these stars deserves attention - namely the right one. This is Beta Lyrae, an eclipsing variable star. The two components of this stellar pair, rotating, outshine each other, which causes brightness fluctuations from 3m.4 to 4m.3 with a period of 12.92 days. And northeast of Vega is the famous multiple star Epsilon Lyrae. Already the naked eye sees here two stars 4 m. The telescope shows that each of them consists of two luminaries - hot white stars similar to Sirius ... The Eagle constellation is easy to recognize by the bright Altair and two stars 3m-4m, "accompanying" it on the sides. Using them as the main reference point, it is easy to find the rest of the stars of the constellation. Its drawing is to a lesser extent than the Swan, but also resembles a flying bird. Well, but for the name, and even for the mythology, it was not. Take, for example, the eagle that Zeus sent to peck out the liver from the chained Prometheus...

Of the sights of the constellation Aquila, it is worth noting Eta Orla - a bright Cepheid that changes its brightness within 3 m.7 - 4 m.4 with a period of 7.18 days. This physically variable star (unlike eclipsing ones, its brightness really changes as a result of pulsations) was discovered somewhat earlier than Delta Cephei, which gave the name to this class of stars, so it would probably be more correct to call them “orlids”. But everything turned out the way it is ... And for the author of these lines, This Eagle became the first variable star that she tried to observe - at the age of 15. I still remember my delight when, after one and a half to two weeks of observations, after doubts - do I correctly evaluate the brilliance, but is my feeling of the difference between the comparison stars correct? - I suddenly saw on my graph instead of chaotic (as it seemed to me) points, a regular Cepheid curve with a fast increase in brightness and a slower decrease ...

The Arabs painted two eagles in place of the Lyra and the Eagle - flying and falling. In Arabic, their names sounded like this: an-Nasr at-Tair and an-Nasr al-Waqi. Now it is easy to see that the modern names of their main stars are abbreviated and distorted names of the constellations. By the way, the name Atair was used before, which is closer in sound to the original. And the Milky Way descends further down, to the south, and passes through the constellations of Ophiuchus, Serpens, Shield, Scorpio and Sagittarius. Since the center of the Galaxy is located in this direction, it is not surprising that these constellations are simply teeming with interesting objects. Globular and open clusters, nebulae, variable stars… It is impossible to describe all this in a short article. We only note that in the constellation Ophiuchus (mythologically it is associated with Asclepius, the god of healing among the ancient Greeks), there is an inconspicuous star of almost 10 magnitude, known as Barnard's star. This red dwarf is one of the nearest neighbors of our Sun. It is the proximity to us that explains the large proper movement in the firmament of this star. In a year, it travels a path of 10.27 arc seconds, and in 188 years it shifts by the size of the diameter of the lunar disk (30 arc minutes). The constellation Serpens is remarkable in that it is the only constellation in the sky, divided into two sections, independent and not in contact with each other (the Head of the Serpent lies to the west of Ophiuchus, the Tail to the east).

The constellation of the Shield is the "young" one, introduced by Jan Hevelius. This is another constellation that owes its name to a specific historical character. The Polish astronomer gave it the name "Shield of Sobieszki" - in honor of his compatriot, commander and king, Jan Sobieski. But astronomers eventually did not accept this name and shortened it. In this constellation, the stars of the Milky Way form a bright cloud, which many people even confuse with a bright terrestrial fog. Scorpion. The constellation owes its name primarily to the similarity of its figure with a scorpion bent in a characteristic pose (unfortunately, at the latitude of Moscow it is not completely visible). But we can see its main star - the red giant Antares. In ancient Greek, this name means "Rival of Mars." Indeed, these two luminaries can be confused when Mars is in Scorpio. But near this constellation is the perihelion of the orbit of Mars, and at opposition in Scorpio, its brightness takes on a negative value, which is much brighter than Antares, which, being a semi-regular variable, changes its brightness from the first to almost the second magnitude. Sagittarius - usually depicted as a centaur holding a bow in his hands. But the characteristic figure of the bright stars of the constellation resembles most of all .... ordinary teapot. It also rises low, and is not entirely visible to us, and this is very unfortunate, because it is in this constellation (and in Scorpio too) that the Milky Way reaches its greatest brightness. This is where the center of our galaxy is located.

To the west of Ophiuchus lie the constellations Hercules and the Northern Crown. The figure of the legendary hero of Ancient Greece is traditionally drawn upside down (upside down). It is noteworthy that, although the constellation is among the ancients, it received its modern name relatively recently - in the 16th century. Most often, the Greeks and Arabs called him simply "Kneeling" - after the pose of an imaginary person. This was reflected in the name of the star Alpha Hercules - Ras Algeti ("the head of a kneeling man"). Among the sights of this constellation, two globular star clusters stand out primarily - M13 and M92. The first of them is one of the closest, brightest and most convenient for observations in the northern sky. Sometimes it can be seen with the naked eye. Even in small telescopes, it can be divided into individual stars. The constellation of the Northern Crown, by its very shape, suggests its name. It is an elegant corolla of stars, and indeed resembles a crown or diadem, adorned with precious stones. Alpha Northern Crown even received the name Gemma - "pearl". Judging by the myths, this crown belonged to Ariadne, who helped Theseus get out of the Labyrinth, but then became the beloved of the god Dionysus ... This small graceful constellation has its southern "double" - there is the constellation of the Southern Crown, with the same correct corolla, but from weaker stars .

There are several more small and inconspicuous, but in their own way interesting and even beautiful constellations in the summer sky. In any case, two of them simply captivate with their modest charm. They are located near the constellations Cygnus and Eagle, and are called Dolphin and Arrow. A first look at these dim groups of stars is enough to appreciate the accuracy of these names! Indeed, the eye sees here both a dolphin in a swift jump and a flying arrow. Both of these small constellations are not inferior in age to Orion and Ursa Major. A little to the east of them lies the constellation Vulpecula. Here, no figures are visible to the eye - only a few faint stars of the fifth magnitude. The ancient astronomers did not see anything either. The constellation was placed in the sky by the same Jan Hevelius in the 17th century.

Another of his "brainchild" is located northeast of the constellation Cygnus. This is the constellation Lizard. There are no bright luminaries in it either, but a zigzag scattering of small stars of 4-5 magnitudes at least remotely resembles the shiny skin of a lizard. This is how Hevelius explained his choice of name, adding, moreover, that “there is not enough room for a larger animal” ... On August nights, the constellations of Pegasus and Andromeda rise high in the east, but nevertheless they already belong to the “autumn” constellations. The annual cycle of the starry sky has come to an end...

What is asterism? Very often you can hear "the constellation of the Big Dipper", "the constellation of the Pleiades" and, as it happened, but most of the inhabitants of the Earth such a phrase will not jar at all. And yet these constellations do not exist! For such notable star groups as the Big Dipper and Small Dipper, Pegasus Square, Summer-Autumn Triangle, Orion's Belt, the Pleiades star cluster, the letter “W” of the constellation Cassiopeia and many others found a special term - asterisms.

In some ways, the asterisms are more important than the constellations themselves. So, for example, to find the North Star, they first find the characteristic Big, and then through it the Small Bucket, and already on the handle of the Small Bucket, the Polar Star is easily found. Or the completely faceless constellation Cancer, famous only for being part of the Zodiac belt and which is detected with the help of the asterism of the Manger, which is included in it.

The most famous and significant asterisms

Big Bucket

Summer-autumn triangle

The most prominent asterism in the northern hemisphere. Consists of three very bright stars located in three constellations. It's in a constellation, in a constellation, and in a constellation.

winter triangle

Triangle of the winter sky of our latitudes. Consists of the brightest star from , from and from . If you add to these stars zetu from the constellation Stern and alpha then you get another asterism - Egyptian cross.

winter circle

Asterism The Winter Triangle is also part of another asterism winter circle. In addition to those mentioned Sirius, Procyon and Betelgeuse this asterism includes and from , Mencalian and from , from and from .

spring triangle

Like all triangles, the Spring one consists of equatorial stars. In our northern latitudes it is visible in spring. Includes from constellation, from and Denebola from . If a star is added to a triangle Carl's heart from , then the resulting rhombus is called Virgo Diamond(or Maiden's necklace) is also an asterism.

"W" Cassiopeia

This asterism, along with Orion's Belt probably easiest to find in the sky. The five stars that form the basis of the constellation lined up in a distinct Latin letter "W".

Big Square

Having finished with triangles, we move on to squares. This asterism is called Great Pegasus Square, but it includes not only three stars but also one of the constellation. And together they form an almost regular square by which it is easy to find and Pegasus and Andromeda. Once all 4 stars were included in the constellation Pegasus but now a star Alferatz refers to Andromeda.

Orion's belt

Three stars lined up in a constellation are easily distinguishable in the sky, and the constellation Orion, thanks to them, is the easiest to find in the northern hemisphere. In ancient times, at different times, these three stars were called three kings or wise men.

scorpion tail

Hyades

Hyades- another star cluster in the constellation Taurus, only slightly inferior to the Pleiades. Together with a star (not included in this asterism) they form a characteristic letter "V". Hyades these are also the daughters of the prolific Atlanta - stepsisters Pleiades.

northern cross

bright constellation stars Swan form an asterism stretched along the Milky Way northern cross. In our latitudes it is visible all year round, but best of all in summer and early autumn. Star Deneb northern cross also included in Summer-autumn triangle.

False Southern Cross

An insidious asterism in the southern hemisphere, which often led sailors astray. Includes four stars from the constellations and, unlike the real Southern Cross, does not point south.

Gorgon head

Irregularly shaped quadrilateral in the constellation , which is commonly associated with the severed head of Medusa Gorgon, which she holds in her hand Perseus. The brightest star of the asterism is the famous Algol- Eye of the Devil.

nursery

One of the most famous star clusters. Located in the constellation along with another asterism donkeys. After Pleiades, Hyades and Stream Ursa Major it is the closest star cluster to Earth.

donkeys

Two stars gamma and delta Cancer called Donkeys (Donkeys). According to legend, they were placed there by Dionysus and it was for them that he built nursery.

Goat and kids

A few more representatives of livestock placed in the sky in the constellation. It is believed that the shepherd holds a goat and kids in his arms - a bright star. Chapel and three small ones. In ancient times they were known as an independent constellation Goat.

Kemble Cascade

A long chain of up to 20 stars from the 5th to the 10th magnitude, distinguishable only in optical instruments in the constellation Giraffe. Only one star with a romantic name is visible to the naked eye. HD 24479.

Egyptian cross

Large asterism that includes another asterism winter triangle and a couple more stars from the constellations Stern and Pigeon. Together they form two isosceles triangles or a cross. Alternative name - St. Andrew's Cross.

The term asterism should not be confused with another term - catasterism, i.e., the association of mythological characters in the form of constellations.

One of the most burning questions that interest beginners in astronomy is this: how to learn to navigate the sky?

The answer is simple: gradually! First you need to learn how to find the brightest stars in the sky and learn their names. Then go from individual stars to groups of stars and learn the location and name of the brightest and most expressive star patterns. After that, you can start working with the star map. Without knowing the location of the brightest stars in the sky, it is difficult to learn celestial orientation using maps (unless it is a planisphere) - you simply do not have landmarks in the sky to compare them with what is shown in the atlas.

That is why start with the simplest observations. On the next fine evening, go outside, stand facing south and look up. You may ask: where, in fact, is the south? South is on the side where the Sun is in your area around noon. You do not need to know a more accurate direction to the south now, although in the future you can determine with the help of the North Star.

So, after the evening twilight, stand facing south and tilt your head up. High in the sky you will see a large triangle formed by three bright stars.

In July, after dark, the Great Summer Triangle is in the southern side of the sky. Pattern: Stellarium

The brightest star forms the top right corner of the triangle. You will notice it even in a relatively bright twilight sky. it Vega, the brightest star in the northern hemisphere of the celestial sphere after Arcturus. Star Deneb forms the upper left vertex. It is much dimmer than Vega, but is still one of the brightest stars in the night sky. Finally, the third star Altair, is under these two stars. In brightness, it occupies an intermediate position between Deneb and Vega.

The stars Vega and Deneb, which make up the base of the triangle, will be located almost at the zenith. The apex of the triangle, marked by the star Altair, is located approximately halfway from the zenith to the horizon - the triangle is, as it were, turned upside down, it “looks” with its apex down.

Before you - one of the most famous star patterns in our sky. It is called the Big Summer Triangle or the Summer Triangle, sometimes the Summer-Autumn Triangle. As the name implies, the best time to observe it is summer and autumn, when the triangle is high in the evenings in the southern side of the sky.

Knowing this stellar figure is useful for several reasons.

Pulling away from her you can study one by one all the summer constellations.
The Milky Way passes through the Summer Triangle. So, the star Deneb lies in its very thick. Having found the Summer Triangle in the sky, you will automatically find the position of the Milky Way.
Inside and around the edges of the Summer Triangle are many celestial attractions: diffuse nebulae, open and globular star clusters, binary and variable stars.

The path of the Milky Way passes through the Summer Triangle. Pattern: Stellarium

You probably noticed that I called the Summer Triangle a figure and a pattern, but I never called constellation- because it's not a constellation, but asterism. The stars that make up the triangle belong to three different constellations. Vega heads the small constellation Lyra, Deneb is part of the very beautiful and expressive constellation Cygnus, and Altair is the main star of the constellation Eagle. All three constellations are perfectly visible in the country sky on dark August or September nights. These are ancient constellations - their age is more than 2000 years.

If you are just starting to get acquainted with the starry sky, be sure to find the Big Summer Triangle on it - it will become your basic star pattern until the end of October.

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