What constellations are near Ursa Major. Constellation Ursa Major

Greek legend tells that in Greece there lived a very beautiful princess named Callisto. Zeus turned her into a bear to save her from Hera's revenge. Big Dipper constellation of the northern hemisphere of the sky. The seven stars of Ursa Major form a shape 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". Best visibility is in March-April. Visible 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 in area (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, Cart, Seven Sages, etc. All the stars of Ursa Major have their own Arabic names: Dubhe (α Ursa Major) means "bear"; Merak (β) - “lower back”; Fekda (γ) - “thigh”; Megrets (δ) - “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 handle of the Bucket is called Benetnash or Alkaid (η); In Arabic, al-Qa'id Banat Nash means "leader of the mourners." This poetic image is taken from the Arabic folk understanding of the constellation Ursa Major. In the system of naming stars using Greek letters, the order of the letters simply corresponds to the order of the stars.

Another version of the interpretation of asterism is reflected in the alternative name Hearse and Mourners. Here the asterism is denoted by a funeral procession: in front are the mourners, headed by the leader, behind them are the funeral stretchers. This explains the name of the star η Ursa Major, “leader of the mourners.”
Alpha, also known as Dubhe, is a yellow giant (magnitude 1.8). Beta, or Merak, is a star white, magnitude 2.4.

Dubhe and Merak are called "Pointers" because... they indicate the direction to the North Star. Gamma, or Phecda, White Star(magnitude 2). The body of the bear ends with Delta, aka Megrez, it 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).

The Ursa Major contains 7 objects included in the Messier Catalog; 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 celestial objects listed, they are located 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 among the top ten constellations in terms of this indicator.

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 Big Dipper telescopes find many interesting objects, which are practically all year round available for observation!

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 a diffuse 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 (at the 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 what 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 exposure!

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: a few more are quite bright stars serve as a wonderful backdrop. 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 light years. For a long time, there have been discussions in the scientific community whether this couple is physically connected or not. The end was reached in 2009, when astronomers at the University of Rochester conducted more than precise 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 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 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.

So we have one more a 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 looking at 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 at a distance of 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

Starα (2000)δ (2000)VAngular distancePeriodNotes
ι B. Ursa08h 59 min+48° 02"3.1m + 10.2m2,0" 817.9 yearsB - double 0.2"
Σ 128008 56 +70 48 7,5 + 7,5 1,9
σ² B. Ursa09 10 +67 08 4,8 + 8,2 + 9,3 4,5; 205 1100
τ B. Ursa09 11 +63 30 4,7 + 10,5 57,1 optical door
Σ 132109 14 +52 41 7,6 + 7,7 17 975
23 B. Medveditsy09 32 +63 04 3,7 + 8,9 22,9
φ B. Ursa09 52 +54 04 5,3 + 5,4 0,3 close couple
Σ 149511 00 +58 54 7,2 + 9,5 34
α B. Ursa11 04 +61 45 1,9 + 4,8 + 7,0 0,7; 378 44,7 close couple
ξ B. Ursa11 18 +31 32 4,4 + 4,9 1,8 59,878 5x
ν B. Ursa11 19 +33 06 3,5 + 9,9 7,2
57 B. Ursa11 29 +39 20 5,3 + 8,3 5,4
ΟΣ 23511 32 +61 05 5,8 + 7,1 0,7 73
Σ 156111 39 +45 07 6,3 + 8,4 + 8,5 9; 85
65 B. Ursa11 55 +46 29 6,7 + 8,3 + 6,5 4,63 triple
78 B. Bears13 01 +56 22 5,0 + 7,4 1,5 115
ζ B. Ursa13 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 rotation of the stars W Ursa Major, they turn towards the Earth, sometimes with a narrower, sometimes 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 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.