Greek legend tells that a very beautiful princess named Callisto lived in Greece. Zeus turned her into a bear to save Hera from revenge. Big Dipper constellation of the northern hemisphere of the sky. The seven stars of Ursa Major make up a figure resembling a ladle with a handle.

How to find the constellation Ursa Major

We must turn our gaze to the north. The term "Settentrione" (Northern) comes from the Latin "Septem triones" which means "seven stars". The best visibility is in March-April. It can be seen throughout Russia throughout the year (with the exception of the autumn months in southern Russia, when Ursa Major descends closest to the horizon).

Major stars and celestial objects.

Ursa Major is the third largest constellation (after Hydra and), whose seven bright stars form the famous Big Dipper; this asterism has been known since ancient times among many peoples under various names: Plow, Elk, Wagon, Seven Wise Men, etc. All the stars of the Big Dipper have their own Arabic names: Dubhe (α Big Dipper) means "bear"; Merak (β) - "lower back"; Fekda (γ) - "thigh"; Megrets (δ) - "the beginning of the tail"; Aliot (ε) - the meaning is not clear (but, most likely, this name means "fat tail"); Mizar (ζ) - "sash" or "loincloth". The last star in the bucket handle is called Benetnash or Alkaid (η); in Arabic, "al-Qaeed banat ours" means "the leader of the mourners." This poetic image is taken from the Arab folk interpretation of the constellation Ursa Major. In the system of naming stars with Greek letters, the order of the letters simply corresponds to the order of the stars.

A different interpretation of the asterism is reflected in the alternative name of the Hearse and the Weepers. Here asterism is indicated by a funeral procession: in front of the mourners, led by the leader, behind them are the funeral stretchers. This explains the name of the star η Ursa Major "the leader of the mourners."
Alpha, aka Dubhe, is a yellow giant ( magnitude 1.8). Beta, or Merak, is a star white color, magnitude 2.4.

Dubhe and Merak are called "Pointers" because they indicate the direction to the North Star. Gamma, or Fekda, is a white star (magnitude 2). The body of the bear ends with Delta, she is Megrez, she is also white, magnitude 3. The most interesting star of the constellation Zeta, or Mizar, is dual system(magnitude Mizar "A" 2.5; Mizar "B" 4.5). Nearby is a faint star - 80 Ursa Major, or Alcor (magnitude 4).

There are 7 objects included in the Messier Catalog in the Ursa Major, they are dim. We are talking about the galaxies M40, M81, M82, M101, M108, and M109, as well as M97. M81 and M82 are the brightest of all the listed celestial objects, they are at a distance of approximately 8 million light years.

Ursa Major ranks third among the constellations in terms of area, but unusually few variable stars have been found there - as of 2011, it is not included in the top ten constellations in this indicator.

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

Here, every observer will find an object to their liking. Ursa Major has dozens of binary and variable stars available for visual inspection, some beautiful asterisms, a planetary nebula, and even an open star cluster. But the main actors, of course, are the galaxies. Ursa Major is a window to the Universe; looking at this section of the sky, we easily penetrate a thin layer of stars nearby 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.

There are a myriad of galaxies in the constellation Ursa Major, many of which are grouped together, as in this image. Almost a thousand galaxies are available for observation in large amateur telescopes in the suburban sky. A photo: Dr. Stefan Binnewies/Josef Popsel

Even a simple listing of all the objects that can be observed in this constellation with an advanced amateur telescope would take up an unreasonable amount of space. Keeping in mind that most amateurs do not have super-expensive instruments, they observe from time to time and in not the most pleasant conditions (flare, cloudiness, and so on), we tried to select only those objects that are the most interesting and exciting, objects that we try to see every true connoisseur of the starry sky should.

But even here we had to divide the article into two parts. In the first part, we will get acquainted with the stars and star patterns of Ursa Major, and the second part will be devoted to deep space objects - nebulae and galaxies. In both cases, we will pass this gigantic section of the sky along and across: from the tip of the tail to the muzzle of the celestial beast and from its withers to its paws. Of course, we will focus on the objects inside the Big Dipper - there is something to see there!

What do we need to travel?

First of all, you need to get a good star atlas or a set of star charts. This is necessary for orientation in the sky and search for the necessary objects - stars, nebulae and galaxies. You can, of course, use the services of a planetarium program such as 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 drawings for their search.
Secondly, equipment. Good astronomical binoculars will suffice for observing variables and some binary stars. The same applies to asterisms and the brightest galaxies. To observe the rest of the objects, you will need a telescope with a 90 mm lens or higher. (Telescopes with a smaller lens are only good for observing some double stars, and other objects are best observed 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.
Thirdly, a truly dark sky is highly desirable. If the described stars can still be observed in the city, then in order to examine nebulous objects it is necessary to reduce the illumination to a minimum. If you have such an opportunity - use 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, of course. This star pattern, formed by seven stars of approximately the same brightness, is known to almost everyone since 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 an important role in the life of civilization for thousands of years, helping sailors, nomads and travelers to navigate the terrain. No wonder all its stars have proper names and some even multiple names! Here they are, if listed from right to left, from the bucket to its handle: Dubhe, Merak, Fekda, Megrets, Aliot, Mizar and Benetnash (or Alkaid). All names are of Arabic origin; they sound unusual, but in translation they mean rather prosaic things, such as: “back”, “thigh”, “lower back”, “base of the tail” and so on.

Big Dipper over the pagoda. A 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 color, with the exception of the Dubhe star, the topmost star in the bucket, which has yellowish color. It is 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 of Orion, where all the bright stars, with the exception of Betelgeuse, are like two drops of water. Perhaps this arrangement of stars in our sky is not accidental?

Really, five of the seven bucket stars are related to each other by a common origin. Observations made in the second half of the 19th century showed that Merak, Fekda, Megrez, Aliot and Mizar are approximately the same distance from us (about 80 light years) and fly in space more or less in the same direction. When astronomers seriously took up the 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 Mizar's optical companion, the star Alcor!

Ursa Major moving group(other name Collider 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. True, here it is necessary to clarify that by now about 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 membership of the cluster is confirmed, this would mean that the Ursa Major Moving Group is much larger than we imagine, and the Sun is in this moment 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 motion vectors of the stars in the cluster are the same, but not equal to the solar ones: the cluster moves obliquely with respect to solar system flying past at a speed of 46 km/s. Conclusion: we are random fellow travelers in this dance of the luminaries.

Other asterisms

In the Big Dipper there are some more entertaining asterisms, 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 illuminated sky, since the stars that make up these drawings are quite weak.

Broken wedding ring

This is perhaps the most famous telescopic asterism in the constellation. Compact and expressive enough, 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 a ring.

Asterism Broken wedding ring in the constellation Ursa Major (bottom of the image). A photo: DSS2

Actually, it is thanks to its characteristic shape that this tiny star pattern got its name, although some observers argue that the asterism is more like 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.

Asterism A broken wedding ring is located at a distance of three discs of the Moon from the star Merak. Picture: Stellarium/Big Universe

Shovel

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

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

The heavenly "shovel" is located between the stars phi and theta Ursa Major. Picture: Stellarium

With 50mm binoculars, you will only see a string of rather faint stars, however, armed with a more powerful tool, such as binoculars with a 70mm lens or a telescope with a wide field of view, you can easily find this important treasure hunt tool!

Shovel photograph taken as part of the Digital Sky Survey project. A photo: DSS2

The figure of asterism is formed by 11 stars 8 m - 10 m; the brightest are the handle of the shovel and its lower rim. The place of attachment of the handle and the upper part 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 slightly strange shovel, a cross between a shovel and a bayonet.

Traveling from the star Merak to Theta Ursa Major, you can sequentially consider both the Broken Wedding Ring and the Spade. Picture: 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 in a telescope with a wide field of view.

Another memorable and very easy to see asterism is close to Mizar and Alcor. We have named this asterism "Pistol", referring to the dispenser pistol handle; English-speaking observers call it Gas Pump Handle - the meaning is preserved.

Asterism The pistol is in the handle of the Big Dipper between Mizar and Benetnash. Picture: Stellarium

The basis of the asterism is formed by four stars of the 6th and 7th stars. led., 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: above the star 82 Ursa Major you will see two more stars 7 m. This is the nose of the gun, where the space fuel comes from. Where is the lever? Inside the 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. Picture: DSS2/Greater Universe

You will see the pistol lever clearly only in a dark sky in an instrument with a lens larger than 70 mm, but the main pattern is perfectly 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 brilliance within 1.5 m.

The last, fifth in a row, asterism known in Ursa Major can be observed with the naked eye. It's called "Horse and Rider" and represents two closely spaced stars, 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 a simple amateur astronomer. Most of them are either too faint to make a proper impression, or too close for small telescopes.

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

On the other hand, Ursa Major has probably the most famous visual double in the entire sky. And Mizar himself is just a reference double star that every owner of a telescope should see! Let's start with this couple.

Mizar and Alcor

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

A pair of stars, Mizar and Alcor, mark the bend in the handle of the Big Dipper. Picture: Stellarium

Outside the city on a dark night, Mizar and Alcor are perfectly visible - in the old days, many peoples checked the sharpness of their eyes using this pair. But today it can be difficult to check your eyesight in this way: in Moscow and other large cities, Alcor is simply not visible due to strong illumination!

But Mizar and Alcor are simply an incredible beauty of the sight, if you look at them through a telescope. Look at the pair first using the lowest magnification. First, pay attention to the color of the stars: it is white with a slight blue tint. Next, look at the surroundings: a few more pretty bright stars serve as a great backdrop. Finally, take a closer look at Mizar. You will find that it consists of two closely spaced stars! .. Amazing picture!

Mizar and Alcor. A 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 were discussions in the scientific community whether this couple is physically connected or not. The point was put in 2009, when astronomers at the University of Rochester made 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 so close to each other that they cannot be separated in any telescope. Alcor has a companion, a dim red dwarf, at a distance of 1″ - it was discovered on images in 2009.

ξ Ursa Major

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

Xi Ursa Major is the southernmost star in the constellation visible to the naked eye. Picture: Stellarium

Xi Ursa Major interesting because it is the first binary star for which an orbit was calculated and the period of revolution was reliably determined. It happened back in 1830! Since then, the stars have orbited their common center of mass three times, allowing astronomers to refine their orbit and period, which is now thought to be 59.878 years.

Orbit ξ Ursa Major. The dots mark the position of the satellite 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 companion of 4.87 m at a distance of 2.5″, which makes it possible to separate the pair into telescopes with a lens over 80 mm. Spectral studies have shown that each of the components, in turn, is a double star. The companions are cool red dwarfs of class M, 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 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 brightness 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 makes up a wide 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 located at different distances from the Earth and ended up in the same part of the sky quite by accident.

The star sigma2 Ursa Major is located in the sky next to the famous pair of galaxies M81 and M82. Once you've had your fill of the distant stellar islands, point your telescope at the double star and view it at high magnification! A 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 examine the star σ² separately through a telescope.

At high magnification, you will notice that sigma² consists of two stars - a companion with a magnitude of 8.3 m is located at a distance of 4 "from the main star. The pair was discovered by Sir William Herschel in 1783, and the positions of the components have been measured since 1832, when Vasily Struve examined the star. As observations have shown, the period of revolution in this system is about 1100 years! The stars passed the 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 growing and will continue to grow for another 200 years!

Orbit of the double star σ² Ursa Major. The dots mark the position of the satellite 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, the brightness of the components, the angular distance between the components, and the period of revolution, if known, are given.

List of double and multiple stars in Ursa Major

Star	α (2000)	δ (2000)	V	Angular dist.	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 dv.
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	5 times
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. Ursa	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; cn. double

variable stars

The choice of variable stars in Ursa Major is huge: in the database on the AAVSO website, there are more than 2800 variable stars in this constellation! The bad news is that almost all of them are quite dim - you need a good telescope to study them.

Of those stars that can be observed with rather modest amateur means, we single out 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 Mirida, and the third, VY Ursa Major, belongs to semiregular variables.

W Ursa Major

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

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 "sharp" sides, exchanging matter.

During the revolution, the stars W of the Big Dipper turn to the Earth either with a narrower or with a wider part. This also leads to a change in the amount of light coming in our direction, which is expressed in a drop in the brightness of the star from 7.8 m to 8.6 m. The most incredible thing about this system is the period of revolution 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 Ursa Major W with binoculars or a telescope. The star is located just below Upsilon Ursa Major, almost halfway to the star Theta.

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

After identifying a star in the sky, you may want to verify its variability and maybe even start serious research. Below is a map of the vicinity of Ursa Major W, on which the brightness of comparison stars is marked with numbers. (80 means magnitude 8.0 m, etc.) Note that the image on the map is inverted, as in a reflecting telescope. To use it with binoculars, rotate it 180 degrees.