When can you see the constellation Ursa Major? Number of bright stars in the Ursa Major bucket

Deep shot of the constellation Ursa Major

The constellation Ursa Major is one of the largest constellations in terms of area, third after Hydra and Virgo. This part of the sky contains more than 200 stars, and up to 125 stars can be distinguished with the naked eye on a moonless night far outside the city.

However, the constellation Ursa Major has become most recognizable thanks to the group of seven stars that form the so-called. Big Bucket. Such easily distinguishable groups of stars are called “asterisms”.

Since people initially associated this area of the sky only with the Big Dipper asterism, most of the existing names were corresponding:

The ancient Greeks called the constellation “Gelika”, which translated means “shell”, sometimes “Arktos” - “ursa” or “bear”. According to some Greek authors, Ursa Major served the ancient Greeks as a navigator. According to the Greek myth, Zeus turned two Cretan nymphs into bears in order to hide them from Kronos. According to another version - the nymph Callisto, to hide from his sister and wife - Hera.
The Indian (Sanskrit) name of the constellation sounds like “Sapta Rishi”, which means “seven sages”. We are talking about the seven sons of the god Brahma, who are considered the ancestors of all, as well as the actual creators of the Universe. In Indian astronomy, the seven stars of the Big Dipper are named after sages.
Kazakh nomads called the constellation “Seven Thieves” (Zhetikarakshy). According to legend, the supreme sky deity Tengri tied his two horses to an Iron Peg. Here the Iron stake (“Temirkazyk”) is, and the horses are two stars close to it (probably Polar A and Polar B). Then the seven stars of the Big Dipper are robbers intent on stealing horses, and therefore they constantly circle around them.
Chinese astronomers called the constellation “North Dipper” (“Beidou”), since at that time the handle of the Big Dipper pointed almost to the north pole.
In Slavic culture, this constellation was called “Elk”, as it was originally associated with this animal. In Ancient Rus', the Big Dipper was also called the “Horse at the Pin,” where the Big Dipper, like a horse pinned to the North Star, constantly moves around it - around the pin.

Stars of the Big Dipper

"Bucket" Ursa Major

The Big Dipper is formed by the following seven stars:

It is noteworthy that the Big Dipper asterism also has another name - “Hearse and Mourners”. According to this idea, the three stars form mourners, headed by a leader (“Al-Qa’id Banat is ours”), behind which a funeral bier moves.

On average, the stars that form the Big Dipper are located at a distance of 120 light years from Earth. These luminaries are not the brightest in our sky; their average magnitude is close to 2m. However, almost everyone will have no difficulty finding them in the sky.

The so-called Ursa Major moving group is distinguished, the core of which consists of 14 stars. 13 of them are included in the constellation Ursa Major, and 5 are in the Big Dipper (Merak, Phekda, Megrets, Aliot and Mizar). Unlike the stars in this group, which move at similar speeds in one direction, the other two Dipper stars (Dubhe and Benetnasha) move in the opposite direction, causing the shape of the Big Dipper to undergo noticeable deformation over the course of 100,000 years.

It is worth saying that in 2009, a new study found that in fact Mizar and Alcor are a sixfold system, where the double luminaries Mizar A and B orbit the double star Alcor. Don't be surprised, they are often born in pairs and in clusters.

Other objects of Ursa Major

In addition to the Big Dipper, in the constellation Ursa Major you can also see an asterism called the Three Leaps of the Gazelle, which looks like three pairs of stars. We are talking about the following pairs:

Alula North South (ν and ξ),
Taniya North and South (λ and μ),
Talitha North and South (ι and κ).

Near Alupa North there is a red dwarf called Lalande 21185, which is elusive to observation with the naked eye. However, it is the sixth closest star system to the Sun. Closer to the stars Sirius A and B.

Observational astronomers are well aware that this constellation contains the galaxy M101 (called Pinwheel), as well as the galaxies M81 and M82. The last two form the core of what is probably the closest group of galaxies, located at a distance of about 7 million light years. In contrast to these distant objects, the astronomical body M 97 (“Owl”) is located within the Milky Way, hundreds of times closer. The Owl is one of the largest planetary nebulae.

In the middle, between the first and second “gazelle jump”, using optics you can see a small yellow dwarf similar to our Sun number 47. From 2000 to 2010, scientists discovered three exoplanets, gas giants, orbiting around it. This star system is also one of the most similar to the Solar System and ranks 72nd on the list of candidates for the search for Earth-like planets carried out as part of the planned NASA Terrestrial Planet Finder mission. So for an astronomy lover, the constellation is of great interest.

In 2013 and 2016, two of the most distant galaxies from us were discovered in the constellation, z8 GND 5296 and GN-z11, respectively. The light from these galaxies, recorded by scientists, lasted 13.02 (z8 GND 5296) and 13.4 (GN-z11) billion years.

Among the non-astronomical facts, it is worth noting that the Big Dipper is depicted on the flag of White Sea Karelia, and on the flag of Alaska - together with the polar star.

Flag of Alaska (left) and White Sea Karelia (right)

List of constellations in the spring sky
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MYTHOLOGY

Callisto(Greek Καλλιστώ) - in Greek mythology, the Arcadian woman, the daughter of Lycaon, was among the companions of Artemis the hunter, was turned into a bear for not retaining her virginity and gave birth to Arkad and Pan. According to another version, she was turned into a beast by Zeus, who tried to hide her from Hera’s jealousy.

When Arkad, who did not know her and was raised by Maya or Hermes, wanted to kill her, Zeus carried both of them to the sky with the constellations: Callisto- Ursa Major, Arcade- Arctophylak (Keeper of the Ursa, now) or the star Arcturus in this constellation. Hera, who pursued her with her anger, deprived her of the opportunity to refresh herself for part of the day in the waves of the ocean; that's why Ursa Major never sets.

In the picture - painting - Francois Boucher "Callisto and Jupiter Zeus takes the form of Artemis"

In Chinese astronomy, the seven stars of the dipper are called the Northern Dipper (Beidou). In ancient times, the handle of the ladle pointed almost to the pole and was used by the Chinese to keep time.

The constellation Ursa Major is associated with one myth, which still worries us today with the tragedy described in it. Once upon a time, King Lycaon ruled in Arcadia. And he had a daughter, Callisto, known throughout the world for her charm and beauty. Even the ruler of Heaven and Earth, the thunderer Zeus, admired her divine beauty as soon as he saw her. Secretly from his jealous wife - the great goddess Hera - Zeus constantly visited Callisto in her father's palace. From him she gave birth to a son, Arkad, who grew up quickly. Slender and handsome, he deftly shot a bow and often went hunting in the forest. Hera learned about the love of Zeus and Callisto. Flowing into a rage, she turned Callisto into an ugly bear. When Arkad returned from hunting in the evening, he saw a bear in the house. Not knowing that this was his own mother, he pulled the bowstring... But Zeus did not allow Arkad, albeit unwittingly, to commit such a serious crime. Even before Arkad fired the arrow, Zeus grabbed the bear by the tail and quickly soared with her into the sky, where he left her in the form of the constellation Ursa Major. But while Zeus was carrying the bear, her tail began to lengthen, which is why the Big Dipper has such a long and curved tail in the sky. Knowing how much Callisto was attached to her maid, Zeus took her to heaven and left her there in the form of a small but beautiful constellation. Zeus and Arcade took them to the sky and turned them into a constellation. forever doomed to take care of his mother, the Big Dipper.19 Therefore, he firmly holds the leashes of the Hound Dogs, which bristle with rage and are ready to pounce on the Big Dipper and tear it apart.

There is another version of this myth. The eternally young goddess Artemis, dressed in hunting clothes, with a bow, quiver and a sharp spear, wandered through the mountains and forests for a long time in search of good game. Following her, her companions and maids moved, resounding with laughter and songs across the mountain peaks. The girls were one more beautiful than the other, but the most charming was Callisto. When Zeus saw her, he admired her youth and beauty. But the maids of Artemis were forbidden to marry. To take possession of her, Zeus resorted to cunning. One night, in the form of Artemis, he appeared before Callisto... From Zeus, Callisto gave birth to a son, Arkad, who quickly grew up and became an unsurpassed hunter. The jealous wife of Zeus, Hera, who learned about her husband's love affair, brought down her anger on Callisto, turning her into an ugly, clumsy bear. One day, Callisto's son Arkad was wandering through the forest, and suddenly a bear came out of the bushes to meet him. Not knowing that it was his mother, he pulled the bowstring, and the arrow flew at the bear... But Zeus, who vigilantly protected his beloved Callisto, at the last moment retracted the arrow, and it flew past. At the same time, Zeus turned Arkad into a small bear cub. After that, he grabbed the bear and the cub by the tails and carried them to the sky. There he left Callisto to shine as the beautiful constellation Ursa Major, and Arcade as the constellation. In the sky, in the form of the constellations Callisto and Arcades, they became even more beautiful than on Earth. Not only people admired them, but also Zeus himself. From the top of Olympus, he often looked at the constellations Big and enjoyed their beauty and continuous movement across the sky. Hera was unpleasant when she saw her husband admiring his pets. She made a fervent plea to the sea god Poseidon to never allow the Big Dipper to touch the sea. Let her die of thirst! But Poseidon did not heed Hera's pleas. Could he really let the beloved of his brother, the thunderer Zeus, die of thirst?! The Big Dipper continues to circle around the pole, while once a day it descends low over the northern side of the horizon, touches the surface of the sea, quenches its thirst and then rises again, attracting the views of people and gods with its beauty.

Interesting Facts

The constellation Ursa Major is featured on the Alaska flag.

The Flag of Alaska is one of the symbols of the American state of Alaska.

The flag was designed in 1926 by 13-year-old Alaska Native Benny Benson, and in 1927 adopted as the official symbol of the Territory of Alaska, which became a state on January 3, 1959.

Eight gold (yellow) five-pointed stars are depicted on a blue background: seven in the image of the Big Dipper and the North Star in the upper right corner.

The Big Dipper symbolizes power, and the North Star symbolizes the north (Alaska is the northernmost territory of the United States).

Source: http://ru.wikipedia.org/wiki/Ursa Major_(constellation)

The most noticeable and well-known constellation to everyone without exception is, of course, the Big Dipper. More precisely, what is clearly visible in the night sky is not itself, but part of it - the Big Dipper. If you look closely, you can see several more stars below and to the right of it, making up the paws and head of the Ursa. The shape of this constellation is really very fascinating. After all, no one has ever seen bears with such long tails.

The number of bright stars in the Ursa Major bucket is clear to everyone. There are exactly seven of them. These stars were named by Arab astrologers back in the Middle Ages.

To our ears their “names” actually sound strange:

Merak.
Mizar.
Fegda.
Megrets.
Dubge.
Alioth.
Benetnash.

From the earth, these stars appear equidistant. In fact, this is far from the case. The number of bright stars in the Big Dipper bucket is seven and they are all not at equal distances from the Earth and the Sun.

Benetnash is located closest to our planet. The farthest star, Alioth, is sixty light years away. However, it looks brighter than Benetnash. This is the brightest and most brilliant object of the Bucket. In terms of the apparent intensity of the emitted light, all the stars in this part of the Big Dipper are close to 2nd magnitude stars.

Noteworthy facts

If you look very closely at one of the stars of the Bucket, Mizar, you can see a faint flicker right next to it. This is explained very simply. Mizar is not an ordinary star, but a double one.

The object located right next to it is called Alcor. From Arabic these two words are translated as “Horse” and “Rider”. Alcor and Mizar are one of the most visible double stars from Earth.

The number of bright stars in the Ursa Major bucket is seven. However, if you look at it through binoculars or a telescope, you can see two more small smears of light. Unlike stars, they look fuzzy and blurry. This is how distant galaxies look from Earth. Located inside the Ursa are called Whirlpool and Pinwheel.

Rotation of the Huge Bucket

The fact that our Earth does not stand still is clear to any schoolchild. Due to its movement, it seems that the stars in the sky are spinning. Kovsh is no exception in this regard. In winter and autumn, Ursa Major is located in the northern part of the night sky, not too high from the horizon. In spring and summer, this most noticeable constellation can be seen almost at its zenith. Moreover, at this time of year the Big Dipper looks upside down.

Celestial compass

So, the number of bright stars in the Big Dipper bucket is exactly seven. Two of them can serve as reference points for those on the move. The fact is that using them it is easy to detect the most famous star in the world - Polaris. This is not difficult to do. You just need to draw an imaginary line along the two outer stars of the Ladle bowl. Next, you should measure approximately the distance between them. The North Star itself is located almost above the northernmost pole.

In ancient times, when there were no navigational instruments yet, it served as a guide for all sailors and travelers. So, if you suddenly find yourself in a difficult situation in an unfamiliar area, look at the constellation Ursa Major. The polar star found from it will show you the way to the north. This small and not too bright celestial object has rescued those lost in the taiga, desert or sea more than once. The North Star leads Ursa Major's closest neighbor, Ursa Minor. The location of both of these “animals” is considered circumpolar according to the systematization of astrologers.

How many stars are there in Ursa Major?

Of course, there are even more stars in this constellation itself than in its most noticeable part - the Bucket. At the moment, there are about 125 of them. This is over a hundred bright objects, against the background of which the Sun would look like a small and dim luminous point. The closest star to Earth, unfortunately, is not even visible to the naked eye. It also doesn't have a name. According to astronomical systematization, it passes as a 7.5 m star. Light from it travels approximately 8.25 years to Earth. This is almost twice as much as from the closest star to us, Alpha Centauri. Thus, the answer to the question of how many stars are in Ursa Major is simple - more than a hundred and not all of them are visible without a telescope or binoculars. To spot a feral animal with a long tail in the Bucket, you actually need to have a pretty rich imagination.

The Legend of Ursa Major

Of course, there simply cannot be many different kinds of myths and legends about such noticeable objects of the night sky as the stars of the constellation Ursa Major. The most popular legend about her was invented by the Greeks. The chroniclers of this old country say that once upon a time the king of Arcadia had an unusually beautiful daughter, Callisto. And this woman was so proud of her attractiveness that she dared to compete with Hera herself, the wife of Zeus. The enraged goddess, using her mystical power, of course, took revenge on the proud woman, turning her into a bear. Callisto's son Arkas, who was returning from a hunt at that time, saw a wild animal at the door of the palace and decided to kill it. However, at the last moment he was stopped by Zeus himself, who was not indifferent to the beauty. After being rescued, Callisto was raised to heaven. The stars of the Ursa Major bucket are what she is. At the same time, the supreme god raised the beauty’s beloved dog to heaven. Nowadays it is known under the name Ursa Minor.

Nearest constellations

The stars in the constellation Ursa Major, or rather in its Bucket, are the most noticeable in the night sky. However, in addition to Ursa Minor, there are several other recognizable constellations in the area. The same Polar Star can become a reference point for finding one of them. Behind it, on the opposite side from the Big Dipper, at approximately the same distance, flaunts Cassiopeia, familiar to many by name. From the outside, this constellation looks like the Russian letter “M”. At certain positions of the Earth, Cassiopeia “turns over” and takes the form of a Latin W.

Between it and Ursa Minor you can see the not so noticeable, but also well-known constellation Cepheus. It does not have a clearly visible form. Between Ursa Major and Ursa Minor it is easy to see the wriggling Dragon. The chain of its stars is easily connected on the map by a broken line.

Well, we hope we have answered the main question of the article about how many luminous permanent objects there are in Ursa Major. There are only seven of them in Kovsh. The main constellation contains about 125 distant “suns”.

The third largest constellation in the sky... An invaluable find for every true astronomy lover living in the northern hemisphere of the Earth. In and around the Big Dipper, telescopes find many interesting objects, which are also available for observation almost all year round!

Here every observer will find an object to his liking. Ursa Major has dozens of double and variable stars available for visual exploration, several beautiful asterisms, a planetary nebula, and even an open star cluster. But the main characters, of course, are the galaxies. The Big Dipper is a window to the Universe; Looking at this part of the sky, we easily penetrate the thin layer of stars close to the Sun and rush into the boundless depths of space. Neither star clouds nor galactic dust prevent us from exploring distant galaxies, because Ursa Major is located away from the Milky Way.

The constellation Ursa Major is home to a myriad of galaxies, many of which are grouped together, as in this image. Almost a thousand galaxies are available for observation with large amateur telescopes in the suburban sky. Photo: Dr. Stefan Binnewies/Josef Pöpsel

Even simply listing all the objects that can be observed in this constellation using an advanced amateur telescope would take up an inordinate amount of space. Bearing in mind that most amateurs do not have super-expensive instruments and observe from time to time and in not the most pleasant conditions (light exposure, cloudiness, etc.), we tried to select only those objects that are the most interesting and exciting, objects that we should try to see a must for every true connoisseur of the starry sky.

But even here we had to divide the article into two parts. In the first, we will get acquainted with the stars and star patterns of the Big Dipper, and the second part will be devoted to deep space objects - nebulae and galaxies. In both cases, we will walk this gigantic section of the sky lengthwise and crosswise: from the tip of the tail to the muzzle of the celestial beast and from its withers to its paws. Of course, we’ll especially focus on the objects inside the Big Dipper - there’s a lot to see there!

What will we need for the trip?

Firstly, you need to get a good star atlas or a set of star charts. This is necessary for orientation in the sky and searching for the necessary objects - stars, nebulae and galaxies. You can, of course, use the services of a planetarium program like Stellarium, but during observations it would be better to have maps at hand - in paper form. In any case, for most of the objects described below we provide pictures to help you find them.
Secondly, equipment. To observe variables and some double stars, good astronomical binoculars will be sufficient. The same applies to asterisms and the brightest galaxies. To observe other objects, you will need a telescope with a 90 mm lens or higher. (Telescopes with a smaller lens are only good for seeing some double stars; other objects are best viewed with binoculars with the same or even a slightly smaller lens.) Obviously, the larger the telescope you have, the fainter objects you will be able to see.
Third, a truly dark sky is highly desirable. If the described stars can still be observed in the city, then to examine foggy objects it is necessary to reduce illumination to a minimum. If you have such an opportunity, take advantage of it.

Well, now we can begin our journey!

The first and simplest object in the constellation Ursa Major, which is perfectly visible to the naked eye at any time of the year, is, of course, . Almost everyone knows this star pattern, formed by seven stars of approximately the same magnitude, from childhood. The Bucket itself is not a constellation; it is only a part, albeit the brightest, of the constellation Ursa Major. Such memorable star patterns that are not constellations are called.

The Big Dipper has played a vital role in the life of civilization for thousands of years, helping sailors, nomads and travelers navigate the terrain. It is not surprising that all its stars have their own names, and some even have several names! Here they are, if listed from right to left, from the ladle to its handle: Dubhe, Merak, Fekda, Megrets, Aliot, Mizar and Benetnash (or Alkaid). All names are of Arabic origin; They sound unusual, but when translated they mean rather prosaic things, such as: “back”, “hip”, “loin”, “base of the tail” and so on.

Big Dipper over the pagoda. Photo: flickr.com/Syu2

Look closely at the stars of the Big Dipper when this asterism is high in the sky and the stars are not twinkling. Did you notice anything? All Stars white, with the exception of the star Dubhe, the uppermost star in the bucket, which is yellowish in color. It’s strange, isn’t it, to see such a cluster of stars comparable in color and brightness in a fairly small area of the sky? Perhaps something similar is observed only in the constellation Orion, where all the bright stars, with the exception of Betelgeuse, are like two peas in a pod. Perhaps this arrangement of stars in our sky is not accidental?

Really, five of the seven bucket stars are related to each other by common origin. Observations made in the second half of the 19th century showed that Merak, Fekda, Megrets, Aliot and Mizar are located at approximately the same distance from us (about 80 light years) and fly through space more or less in the same direction. When astronomers seriously took inventory of their celestial economy, it turned out that in the vicinity of the Big Dipper there are about a dozen more stars that follow the galactic orbit along with our five. Among them is the optical satellite of Mizar, the star Alcor!

Ursa Major Moving Group(other name Collinder 285) is the closest open star cluster to Earth. The distance to its center is estimated at 75-80 light years, and the diameter of the cluster is 30 light years. However, it is necessary to clarify here that to date, approximately 40 more stars have been identified that may belong to the group. The Ursa Major stream, as astronomers call the collection of these stars, includes luminaries scattered throughout the sky - from the constellation Cepheus to the Southern Triangle. If their belonging to the cluster is confirmed, this will mean that the Ursa Major Moving Group is much larger than we imagine, and the Sun is currently located inside the cluster.

Does this mean that the Solar System is part of an open star cluster? No. The age of the Ursa Major Moving Group does not exceed 300 million years - the Sun is almost 10 times older. The velocities and vectors of motion of the stars in the cluster are the same, but not equal to the solar ones: the cluster moves obliquely relative to the Solar System, flying past at a speed of 46 km/s. Conclusion: we are random fellow travelers in this dance of luminaries.

Other asterisms

There are several more interesting asterisms in Ursa Major, which, however, are not as easy to find as the Big Dipper. To observe them, you will need good astronomical binoculars with a lens over 50 mm and a not too overexposed sky, since the stars included in these pictures are quite faint.

Broken wedding ring

This is perhaps the most famous telescopic asterism in the constellation. Compact and quite expressive, it is an excellent target for binoculars and small telescopes. The asterism consists of ten stars 7 m - 11 m, forming a semi-ring with a diameter of half the lunar disk. The brightest star in this chain looks like a diamond embedded in the ring.

Asterism Broken Wedding Ring in the constellation Ursa Major (bottom of the photo). Photo: DSS2

In fact, it is thanks to its characteristic shape that this tiny star design got its name, although some observers argue that the asterism is more reminiscent of a papal tiara than a wedding ring, albeit a broken one.

Finding the Broken Wedding Ring is easy: the asterism is located 1.5° west (to the right) of the star Merak, the lowest star in the Big Dipper. By the way, this pseudocluster also has an “official” name: Sachariassen 1.

The Broken Wedding Ring asterism is located at a distance of three lunar disks from the star Merak. Drawing: Stellarium/Big Universe

Shovel

We wrote above that Ursa Major is a real treasury of interesting space objects. To dig it out, you need a good shovel. And it exists!

Be sure to take a look at the Lopata asterism, which is located between the stars phi (φ) and theta (θ) of Ursa Major!

The celestial “shovel” is located between the stars phi and theta of Ursa Major. Drawing: Stellarium

With 50mm binoculars you'll only see a string of fairly faint stars, but with a stronger tool like 70mm binoculars or a wide-field telescope, you'll easily spot this important treasure hunter's tool!

Photo of “Shovels” taken as part of the Digital Sky Survey project. Photo: DSS2

The asterism figure is formed by 11 stars 8 m - 10 m; the brightest ones are the handle of the shovel and its lower rim. The place where the handle is attached and the top of the shovel itself are marked with stars of the 10th magnitude. Please note: the tip of the shovel is blunt, there is clearly one star missing! Therefore, this is a bit of a strange shovel, something between a shovel and a bayonet.

Traveling from the star Merak to theta Ursa Major, you can successively see both the Broken Wedding Ring and the Shovel. Drawing: Stellarium

The diameter of the asterism is 1° or two apparent diameters of the Moon. It is best to observe the Shovel in its entirety, of course, through binoculars, but it also looks quite good through a telescope with a wide field of view.

Another memorable and very easy to observe asterism is located near Mizar and Alcor. We called this asterism "Pistol", referring to the handle of the gas pump's pistol; English-speaking observers call it Gas Pump Handle - the meaning remains the same.

The Asterism Pistol is located in the handle of the Big Dipper between Mizar and Benetnash. Drawing: Stellarium

The basis of the asterism is formed by four stars of the 6th and 7th stars. Vel., forming an irregular parallelogram. The brightest of these stars, 82 Ursa Major, is visible outside the city at the limit of visibility even with the naked eye, so finding a parallelogram with binoculars will not be difficult.

Now the most interesting thing: above the star 82 Ursa Major you will see two more stars 7 m. This is the nose of the gun where space fuel comes from. Where's the lever? Inside a parallelogram! It is formed by a chain of stars 9 m - 11 m, coming from 82 Ursa Major.

With some imagination, the tanker's pistol is quite easily recognizable in this star pattern. Drawing: DSS2/Big Universe

You will see the pistol lever clearly only in a dark sky with an instrument with a lens larger than 70 mm, but the main pattern is clearly visible already in 50 mm prism binoculars.

By the way, pay attention to the star HD 118668, which is part of this asterism. It is a distant red giant located at least 1000 light years away. years from Earth! In addition, there are suspicions that it changes its gloss within 1.5 m.

The last, fifth, asterism known in Ursa Major can be observed with the naked eye. It's called "Horse and Rider" and represents two stars located close to each other, Mizar and Alcor. But it will be discussed below, in the section on double and multiple stars.

Double and multiple stars in Ursa Major

There are a huge number of double stars in the constellation Ursa Major, but not all of them are of interest to the average astronomer. Most are either too faint to make a proper impression or too cramped for smaller telescopes.

Orbits of close double stars ι Ursa Major and Dubhe (α constellation). Source: Burnham's Celestial Handbook

On the other hand, Ursa Major has what is probably the most famous visual double in the entire sky. And Mizar himself is simply a standard double star that every telescope owner should see! Let’s start with this pair, perhaps.

Mizar and Alcor

Mizar- the second star, if you count from the end of the handle of the Big Dipper. It's located on the bend of the handle, so it's incredibly easy to find. You will not confuse Mizar with neighboring stars also because it has a satellite - a faintly luminous star 4 m, to which Arab astronomers gave the name Alcor. Traditionally, Mizar is translated from Arabic as “Belt” or “Sash”, and Alkor as “Weak” (from the word Al Khawwar), but we are used to calling them Horse and Rider. This well-known name is not a translation of their names - this is how Europeans called the couple in the Middle Ages. In fact, Mizar and Alcor - Horse and Rider - is another, fifth asterism of the Big Dipper.

The pair of stars Mizar and Alcor mark the curve of the handle of the Big Dipper. Drawing: Stellarium

Outside the city on a dark night, Mizar and Alcor are clearly visible - in ancient times, many people used this pair to check their eye sharpness. But today it can be quite difficult to test your eyesight in this way: in Moscow and other large cities, Alcor is simply not visible due to strong light!

But Mizar and Alcor are simply an incredibly beautiful sight when you look at them through a telescope. First look at the pair using the lowest magnification. First, pay attention to the color of the stars: it is white with a slight blue tint. Next, look at your surroundings: several more fairly bright stars serve as an excellent background. Finally, take a closer look at Mizar. You will find that it consists of two stars located close to each other!.. Stunning picture!

Mizar and Alcor. Photo: DSS2

Mizar and Alcor are separated in our sky by 12 arc minutes - almost a third of the lunar disk. In reality, the distance between the stars is almost a quarter of a light year. For a long time, there have been discussions in the scientific community whether this couple is physically connected or not. The end was set in 2009, when astronomers at the University of Rochester carried out more accurate measurements and showed that both stars are part of a physically connected system consisting of... 6 stars! It turns out that both components of Mizar and Alcor itself - all three stars are double! Mizar A and Mizar B are spectral binaries; The components in these systems are located so close to each other that they cannot be separated by any telescope. Alcor has a companion, a dim red dwarf, at a distance of 1″ - it was discovered in images in 2009.

ξ Ursa Major

This is perhaps the most remarkable double star of Ursa Major after Mizar. It can be found on one of the hind legs of Ursa Ursa, south of the other bright stars of this constellation.

Xi Ursa Major is the southernmost star of the constellation that is visible to the naked eye. Drawing: Stellarium

Xi Ursa Major interesting because it is the first double star for which the orbit was calculated and the orbital period was reliably determined. This happened back in 1830! Since then, the stars have revolved around the common center of mass three times, allowing astronomers to refine the orbit and period, which today is considered to be 59.878 years.

Orbit ξ Ursa Major. The dots mark the position of the companion star in different years. Source: James Mullaney. Double and Multiple Stars and How to Observe Them

Both components are very similar in their characteristics to the Sun. The main star with a magnitude of 4.41 m is separated from the satellite 4.87 m at a distance of 2.5″, which makes it possible to separate the pair in telescopes with an objective lens over 80 mm. Spectral studies have shown that each of the components, in turn, is a double star. The companions are cool M-class red dwarfs, but there is no exact information about these stars. Finally, in 2012, another component of the system was discovered - a distant brown dwarf of spectral type T.

Thus, we have before us another complex system consisting of 5 luminaries! It is located at a distance of 29 light years from Earth.

σ² Ursa Major

Another interesting double star - sigma² Ursa Major, located to the right of the bucket. The magnitude of σ² is 4.80 m - it is quite visible to the naked eye in the suburban sky. The color of the star is white with a yellowish tint. Together with the star σ¹, it forms a broad pair of stars, comparable to Mizar and Alcor, but, of course, not as bright and noticeable. This is an optical double star, that is, its components are not physically connected to each other, are at different distances from the Earth and ended up in the same part of the sky completely by chance.

The star Sigma2 Ursa Major is located in the sky next to the famous pair of galaxies M81 and M82. When you've had your fill of distant star islands, point your telescope at the double star and view it with high magnification! Photo: DSS2

Together with the star ρ Ursa Major, the pair forms a small isosceles triangle. On ancient maps, the ears of the Bear were depicted in this place. Explore the area with binoculars, and then look at the star σ² separately through a telescope.

At high magnification, you will notice that Sigma² consists of two stars - the 8.3 m satellite is located 4″ from the main star. The pair was discovered by Sir William Herschel in 1783, and measurements of the positions of the components have been carried out since 1832, when the star was examined by Vasily Struve. As observations have shown, the period of revolution in this system is about 1100 years! The stars passed periastron in the first half of the 20th century and are now moving away from each other. The angular distance between the components is slowly increasing and will continue to do so for another 200 years!

Orbit of the double star σ² Ursa Major. The dots mark the position of the companion star in different years based on a 700-year period. Source: Robert Burnham's Celestial Handbook

The distance to this pair is 66 light years. This means that the main star is 5 times brighter than the Sun, and its companion is 5 times dimmer. Apparently, σ² B is a typical orange dwarf.

Below is a list of interesting double stars in Ursa Major. For stars, the coordinates, brightness of the components, angular distance between the components and the orbital period, if known, are indicated.

List of double and multiple stars in Ursa Major

Star	α (2000)	δ (2000)	V	Angular distance	Period	Notes
ι B. Ursa	08h 59 min	+48° 02"	3.1m + 10.2m	2,0"	817.9 years	B - double 0.2"
Σ 1280	08 56	+70 48	7,5 + 7,5	1,9
σ² B. Ursa	09 10	+67 08	4,8 + 8,2 + 9,3	4,5; 205	1100
τ B. Ursa	09 11	+63 30	4,7 + 10,5	57,1		optical door
Σ 1321	09 14	+52 41	7,6 + 7,7	17	975
23 B. Ursa	09 32	+63 04	3,7 + 8,9	22,9
φ B. Ursa	09 52	+54 04	5,3 + 5,4	0,3		close couple
Σ 1495	11 00	+58 54	7,2 + 9,5	34
α B. Ursa	11 04	+61 45	1,9 + 4,8 + 7,0	0,7; 378	44,7	close couple
ξ B. Ursa	11 18	+31 32	4,4 + 4,9	1,8	59,878	5x
ν B. Ursa	11 19	+33 06	3,5 + 9,9	7,2
57 B. Ursa	11 29	+39 20	5,3 + 8,3	5,4
ΟΣ 235	11 32	+61 05	5,8 + 7,1	0,7	73
Σ 1561	11 39	+45 07	6,3 + 8,4 + 8,5	9; 85
65 B. Ursa	11 55	+46 29	6,7 + 8,3 + 6,5	4,63		triple
78 B. Bears	13 01	+56 22	5,0 + 7,4	1,5	115
ζ B. Ursa	13 24	+54 56	2,3 + 4,0	14,4		Mizar; 4-fold system
80 B. Ursa			4,0	708,7		Alcor; sp. double

Variable stars

The selection of variable stars in Ursa Major is enormous: the database on the AAVSO website lists more than 2,800 variable stars in this constellation! The bad news is that almost all of them are quite dim - you'll need a good telescope to study them.

Of those stars that can be observed with fairly modest amateur means, we will highlight three: W, R and VY Ursa Major. The first star belongs to the eclipsing variable stars, R Ursa Major is a long-period variable or Mira, and the third, VY Ursa Major, belongs to the semi-regular variables.

W Ursa Major

The star is especially interesting W Ursa Major. It belongs to the type of so-called eclipsing variables. The famous "devil's star", Algol, belongs to the same type, but W Ursa Major is a much more extreme example of this kind of star.

See for yourself. Like all eclipsing variables, W Ursa Major is a double star. The components that make up this system are very similar in their characteristics to our Sun, but are located so close to each other that under the influence of mutual attraction they changed their usual spherical shape and turned into elongated ellipsoids. Moreover, both stars filled the so-called Roche lobe and touch each other at one of the Lagrangian points! Circling around a common center of mass, these two melon-shaped luminaries are always turned to each other with their “sharp” sides, exchanging matter.

During the revolution of the star W Ursa Major, the narrower and then the wider part turns towards the Earth. This also leads to a change in the amount of light coming in our direction, which is expressed in a drop in the star’s brightness from 7.8 m to 8.6 m. The most incredible thing about this system is the rotation period of the components: it is only 8 hours or 0.33 Earth days! This means that the entire cycle can in principle be tracked within one night!

You can observe the Big Dipper with binoculars or a telescope. The star is located just below upsilon Ursa Major, almost halfway to the star theta.

The W of the Big Dipper is located between the body and the front paw of the celestial beast. Drawing: Stellarium/Big Universe

After identifying a star in the sky, you may want to make sure it is variable and maybe even begin some serious research. Below is a map of the vicinity of W Ursa Major, on which the brightness of the comparison stars is marked with numbers. (80 means magnitude 8.0 m, etc.) Note that the image on the map is inverted, like in a reflecting telescope. To use it when observing through binoculars, rotate it 180 degrees.

Map of the surrounding area of W Ursa Major with comparison stars.

Ursa Major (lat. Ursa Major) is a constellation in the northern hemisphere of the sky. The seven stars of Ursa Major form a shape resembling a ladle with a handle. The two brightest stars, Alioth and Dubhe, have a magnitude of 1.8 apparent magnitude. By the two extreme stars of this figure (α and β) you can find the North Star. The best visibility conditions are in March - April. Visible throughout Russia all year round (with the exception of the autumn months in southern Russia, when Ursa Major descends low to the horizon).

Short description

Big Dipper
Lat. Name	Ursa Major (genus Ursae Majoris)
Reduction	UMa
Symbol	Big Dipper
Right ascension	from 7 h 58 m to 14 h 25 m
Declension	from +29° to +73° 30’
Square	1280 sq. degrees (3rd place)
Brightest stars (value< 3 m)	Alioth (ε UMa) – 1.76 m Dubhe (α UMa) – 1.81 m Benetnash (η UMa) – 1.86 m Mizar (ζ UMa) – 2.23 m Merak (β UMa) – 2.34 m Fekda (γ UMa) – 2.41 m
Meteor showers	Ursids Leonids-Ursids April Ursids
Neighboring constellations	The Dragon Giraffe Little Leo Veronica's hair Hound Dogs Bootes
The constellation is visible at latitudes from +90° to -16°. The best time for observation is March.

Detailed description

The constellation Ursa Major is located in the northern hemisphere of the starry sky. People have known it for many thousands of years. He was known to astronomers in Egypt, Babylon, China and Ancient Greece. It was included by Claudius Ptolemy in his monograph “Almagest” back in the 2nd century. And this work united all the knowledge on astronomy for that period of time.

The Big Dipper is formed by the following seven stars:

Dubhe (Alpha Ursa Major), the name comes from the Arabic expression - “back of the big bear.”
Merak (β) – from Arabic “loin” or “groin”.
Fekda (γ) – “thigh”.
Megrets (δ) – “base of the tail.” It is the faintest star among the stars of the Big Dipper.
Aliot (ε) – “fat tail”. The brightest star in this constellation.
Mizar (ζ) – from Arabic – “belt”. Near Mizar there is another star - Alcor. It is noteworthy that the ability to distinguish between these two stars is a consequence of good vision (with myopia of no more than 1 diopter).
Benetnash (η) or otherwise – Alkaid. The third brightest star in Ursa Major. “Al-Qaeda banat ours” is translated from Arabic as “leader of the mourners.”

As you can see, this formation includes 7 stars. If you connect them with a straight line, you get a figure that resembles a ladle with a handle. Each star has its own name. At the top point of the bucket, opposite the handle, there is a star, which is called Dubhe. It is the second brightest among its cosmic counterparts. This is a multiple star. That is, several stars from Earth are seen as one due to their close distance to each other.

In this case we are dealing with 3 stars. The largest of them is a red giant. That is, the core has already lost all its hydrogen reserves, and a thermonuclear reaction is taking place on the surface of the star. It dies, and over time it should turn into a white dwarf or become a black hole. The other two stars are Main Sequence stars, that is, the same as our Sun.

On the same straight line with Dubhe, at the base of the bucket, there is a star Merak. This is a very bright light. It is 69 times brighter than our Sun, but due to the vastness of outer space it does not make the proper impression. If the straight line between Merak and Dubhe is extended towards the constellation Ursa Minor, then you can run into the North Star. It is located at a distance that is 5 times the distance between the indicated luminaries.

The other lowest point of the bucket is called Fekda. This is a Main Sequence star. The top point of the bucket located opposite it is called Megrets. She is the dimmest in the friendly company. This star is almost 1.5 times larger than our star and 14 times brighter.

There is a star at the beginning of the handle Aliot. It is the brightest in the constellation Ursa Major. Among all the visible stars in the sky, it ranks 33rd in brightness. From the end of the handle it is the third in a row, and the second is a star Mizar. Next to it there is another luminary, which is called Alcor. Anyone with good eyesight can see it. They say that in ancient times, Alcor was used to test the visual acuity of young men who aspired to become sailors. If a young man could see this star next to Mizar, then he was enrolled as a sailor.

In reality, not 2 stars shine in the cosmic distance, but as many as 6. These are the double stars Mizar A and Mizar B, as well as the double star Alcor. But from Earth, with the naked eye, only a large bright point and a small one that is nearby are visible. These are the kind of surprises that space sometimes brings.

And finally, the outermost star. It is called Benetnash or Alkaid. All these names are taken from Arabic. In this case, the literal translation means “leader of the mourners.” That is, the alkaid is the leader, and our banat is the mourners. This star is the third brightest after Aliot and Dubhe. It ranks 35th among the brightest stars in the sky.

The brightest stars of Ursa Major

Star	α (2000)	δ (2000)	V	Sp. Class	Distance	Luminosity	Notes
Aliot	12h 54min 01.7s	+55° 57′ 35″	1,76	A0Vp	81	108
Dubhe	11 03 43,6	+61 45 03	1,79	K0IIIa	124	235	Triple. ΑΒ=0.7″ AC=378″
Benetnash	13 47 32,3	+49 18 48	1,86	B3V	101	146
Mizar	13 23 55,5	+54 55 31	2,27	A1Vp	86	71	6 star system including Alcor A and B
Merak	11 01 50,4	+56 22 56	2,37	A1V	78	55
Fekda	11 53 49,8	+53 41 41	2,44	A0Ve	84	59
ψ UMa	11 09 39,7	+44 29 54	3,01	K1III	147	108
μUMa	10 22 19,7	+41 29 58	3,05	M0III	249	296	sp. double?
ιUMa	08 59 12,4	+48 02 30	3,14	A7IV	48	10	sp. double and wholesale double
θ UMa	09 32 51,3	+51 40 38	3,18	F6IV	44	8

Other objects of Ursa Major

In addition to the Big Dipper, in the constellation Ursa Major you can also see an asterism called the Three Leaps of the Gazelle, which looks like three pairs of stars.

We are talking about the following pairs:

Alula North South (ν and ξ),
Taniya North and South (λ and μ),
Talitha North and South (ι and κ).

This is how we can characterize the constellation Ursa Major, known since ancient times. This cosmic region also includes many galaxies. For example, the Pinwheel galaxy. It is better known as M 101. In size it exceeds the Milky Way. Its detailed photographs were taken by the Hubble telescope at the beginning of the 21st century. To get to this huge cluster of stars, you need to spend 8 million light years.

The Owl Nebula is also of interest. It enters our galaxy and looks like two dark spots located nearby. In 1848, Lord Ross believed that these spots were similar to the eyes of an owl. This is where the name came from. This nebula is approximately 6 thousand years old, and it is located at a distance of 2300 light years from the Solar system.

But the most interesting thing is that the constellation Ursa Major is considered as one of the likely sources of extraterrestrial intelligence. In this part of space there is a certain star called 47UMa. It is a yellow dwarf and its planetary system is very similar to our solar system. At least, today there are 3 known planets orbiting this star. In 2003, a radio message was sent to him. Earthlings persistently search for brothers in mind, and luck always accompanies those who persist.

How to find the Big Dipper in the sky?

If you want to learn how to navigate the starry sky, then your primary task is to be able to find the Big Dipper bucket. Although it is not far from the North Star, it is still not so close to it as to be at one point in the sky all the time.

The Big Dipper is easiest to spot in the fall and winter. At this time, in the evenings, the asterism is located in the north, low above the horizon and in our usual position.

Towards the end of winter, the position of Ursa Major in the evening sky changes. The seven stars of the bucket shift to the east, and the Big Dipper itself stands vertically on the handle.

There is nothing surprising. Let us remember that every day all the stars describe circles around the celestial pole, thereby reflecting the rotation of the Earth around its axis. But over the course of a year, the stars make one more additional circle, thereby reflecting the movement of the Earth in its orbit around the Sun. The stars of Ursa Major are no exception - moving from the lowest point, the bucket seems to rear up.

In mid-spring, Ursa Major is at its zenith in the evenings, right above your head! At this time, it is in an inverted position in relation to the North Star. Its ladle faces west, and its handle faces east.

For those who live north of Moscow, the most difficult time to find the Big Dipper in the sky is in the summer, during the period of short nights. At this time, the constellation is in the west, and the bucket is tilted down and looking north.

How to find the North Star using Ursa Major?

Now let's see how to find the North Star using Ursa Major. This is done simply. Take the two outermost stars in the bucket, Dubha and Merak (alpha and beta Ursa Major), and mentally connect them with a line. And then extend this line five times the distance Merak - Dubhe.

You will see a star whose brilliance is approximately equal to the brilliance of the stars of the bucket. This is the famous Polar Star, the “iron nail,” as the Kazakhs called it, meaning the immobility of the Polar Star in the earth’s firmament.

Knowing the position of the North Star, you can easily navigate in space. Draw a plumb line from Polyarnaya down. The place where it intersects with the horizon will point north. The rest of the cardinal directions are easy to find: east will be on the right, south behind you, and west on the left. So, guided by the stars, in Russia in the Middle Ages they built the Moscow-Yaroslavl and Moscow-Vladimir roads, straight as an arrow.

Secrets of the constellation Ursa Major: how different peoples saw it

Egypt "Bull's Thigh"

The ancient Egyptians were among the first astronomers in history, with some of their round stone "observatories" dating back as far as the fifth millennium BC. It was the Egyptians who laid the foundations of the constellation system that was borrowed from them by the inhabitants of Mesopotamia, the Greeks, the Arabs, and then by modern science. At that dizzyingly distant time, due to the precession of the earth's axis, it was not the North Star that pointed north, but Alpha Draconis (Thuban). Its surroundings, together with the nearest luminaries, were considered by the Egyptians to be the “fixed sky,” the habitat of the gods. Instead of a ladle, the priests could see the leg of Set, the god of war and death, who turned into a bull and killed Osiris with a blow of his hoof. Falcon-headed Horus cut off his limb in revenge for the murder of his father.

China "Emperor Shangdi's Cart"

The astronomers of Ancient China divided the sky into 28 vertical sectors, “houses,” through which the Moon passes on its monthly journey, just as the Sun passes through the signs of the Zodiac in its annual rotation in Western astrology, which borrowed the 12-sector division from the Egyptians. In the center of the heavens, like an emperor in the capital of a state, the Chinese placed the North Star, which by that time had already taken its usual place. The seven brightest stars of the Big Dipper are located in honorable proximity to it, within the Purple Fence - one of the three Fences surrounding the palace of the “royal” star. They could be described as the Northern Dipper, whose orientation corresponds to the seasons, or as part of the carriage of the Shangdi Heavenly Emperor.

India "Seven Wise Men"

Observational astronomy in ancient India did not develop as brilliantly as, say, mathematics. Its ideas were greatly influenced by both Greece and China - for example, the 27-28 “stays” (nakshatras) through which the Moon passes in about a month are very reminiscent of the Chinese lunar “houses”. Hindus also attached great importance to the North Star, which, according to experts in the Vedas, is the abode of Vishnu himself. The Ladle asterism located underneath it was considered the Saptarishas - seven sages born from the mind of Brahma, the forefathers of the world of our era (Kali Yuga) and everyone living in it.

Greece "Bear"

Ursa Major is one of 48 constellations listed in Ptolemy's star catalog around 140 BC, although it was first mentioned much earlier, in Homer. The intricate Greek myths offer different backstories for its appearance, although everyone agrees that the bear is the beautiful Callisto, companion of the hunter goddess Artemis. According to one version, using his usual tricks with transformation, the loving Zeus seduced her, provoking the wrath of both his wife Hera and Artemis herself. Saving his mistress, the Thunderer turned her into a bear, who wandered in the mountain forests for many years until her own son, born of Zeus, met her while hunting. The Supreme God had to intervene once again. Preventing matricide, he ascended both to heaven.

America "Great Bear"

It seems that the Indians understood something about wild animals: in the Iroquois legend about the origin of the asterism, the “heavenly bear” does not have any tail. The three stars that form the handle of the ladle are three hunters pursuing the beast: Aliot draws a bow with an arrow embedded in it, Mizar carries a cauldron for cooking meat (Alcor), and Benetnash carries an armful of brushwood to light the fire. In the fall, when the Bucket turns and sinks low to the horizon, the blood from the wounded bear drips down, painting the trees in variegated colors.

The closest bright star in Ursa Major– star South Alula or xi Ursa Major. This is a beautiful double star that can be separated into its components in a telescope with a lens greater than 80mm. Both components are similar in their characteristics to the Sun and each of them also has a satellite - a cool red dwarf! The distance to ξ Ursa Major is 29 sv. years. A little further away is the star θ - 44 light years from the Sun. Well, the farthest of the bright stars in the constellation is the red giant μ Ursa Major, one of the stars in the front “paw” of the Ursa Major. The distance to it is 249 light years.
The constellation Ursa Major is featured on the Alaska flag. The flag of White Sea Karelia, which was approved on June 21, 1918, depicts the Big Dipper. Also, the flag with the image of the Big Dipper is used by Irish left-wing radical organizations.
You can admire the Big Dipper during the day. This can easily be done by finding it on one of the interactive constellation maps. On the maps you can find other large and small constellations and look at them at close range.
Need I say that the huge constellation Ursa Major is a real treasure trove for a true astronomy lover?! This part of the sky contains a huge number of attractions that can be observed with small telescopes: double and variable stars, several bright galaxies and dozens of fainter galaxies, an open star cluster and even a planetary nebula. There is no way to fit descriptions of these objects into one article. Therefore, we decided to publish separate articles devoted to observations of the sights of the Big Dipper.