The eighth star in the Ursa Major. The constellation Ursa Major and Ursa Minor in the sky: a list of stars, how to find, legends and description
The most noticeable and well-known constellation to everyone without exception is, of course, the Big Dipper. Rather, it is not she herself that is clearly visible in the night sky, but her part - the Big Dipper. If you look closely, then below and to the right of it you can see a few more stars that make up the paws and head of the Bear. The shape of this constellation is really very interesting. After all, no one has ever seen bears with such long tails.
The most visible part of the constellation
The number of bright stars in the bucket Big Dipper everyone knows. There are exactly seven of them. The name of these stars was given by Arab astronomers in the Middle Ages. To our ear, their "names" sound really strange:
- Merak.
- Mizar.
- Fegda.
- Megrets.
- Dubge.
- Aliot.
- Benetnash.
From the ground, these stars appear equidistant. In fact, this is far from the case. The number of bright stars in the Big Dipper's bucket is seven, and they are all not at equal distances from the Earth and the Sun.
The closest to our planet is Benetnash. Before - Aliot - sixty Nevertheless, she looks brighter than Benetnash. This is Bucket's brightest and brightest object. By the apparent intensity of the emitted light, all the stars in this part of the Big Dipper are close to the stars of the second magnitude.
If you look very closely at one of the Bucket's stars, Mitsaru, you will notice a faint flicker right next to it. The explanation is very simple. Mizar is not an ordinary star, but a double one.
The object located right next to it is called Alcor. These two words are translated from Arabic as "Horse" and "Rider". Alcor and Mizar are one of the most visible binary stars from Earth.
The number of bright stars in the Big Dipper bucket is seven. However, if you look at it through binoculars or a telescope, you can see two more small strokes of light. Unlike stars, they look fuzzy and blurry. This is how distant galaxies look from Earth. The ones located inside the Dipper are called Whirlpool and Pinwheel.
Rotation of the Big Dipper
Any schoolchild knows that our Earth does not stand still. Due to its movement, the stars in the sky appear to be rotating. Bucket is no exception in this regard. In winter and autumn, the Big Dipper 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.
Heavenly compass
So, the number of bright stars in the Big Dipper bucket is exactly seven. Two of them can serve as a guide for those on the road. The fact is that from them it is easy to find the most famous star in the world - Polar. This is not difficult to do. You just need to draw an imaginary line along the two outer stars of the Bucket bowl. Further on it 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 navigation devices yet, it was she who served as a reference point 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 North Star found on it will show you the way to the north. This small and not too bright celestial object has already helped out lost in the taiga, in the desert or in the sea more than once. The Polar Star leads the Big Dipper's closest neighbor, Ursa Minor. The area of \u200b\u200blocation of both of these "animals" is considered by astronomers to be circumpolar.
How many stars are in the Big Dipper
Of course, there is much more in this itself than in its most noticeable part - the Bucket. At the moment, about 125 of them are known. These are over a hundred bright objects, against which the Sun would look like a small and dim luminous point. The star closest of them to Earth, unfortunately, is not even visible to the naked eye. It also has no name. According to the astronomical classification, it passes like a 7.5 m star. The light from it to the Earth takes about 8.25 years. This is almost double that of the closest star to us - Alpha Centauri. Thus, the answer to the question of how many stars are in the Big Dipper is simple - more than a hundred, and not all of them are visible without a telescope or binoculars. To make out a wild beast with a long tail in the Bucket, in fact, you need to have a fairly rich imagination.
The Legend of the Big Dipper
Of course, many different kinds of myths and legends simply cannot but exist about such noticeable objects of the night sky as the stars of the constellation Ursa Major. The most famous legend about her was invented by the Greeks. The chroniclers of this ancient country say that the king of Arcadia once had an unusually beautiful daughter, Callisto. And this girl was so proud of her attractiveness that she dared to compete with the Hero 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. The son of Callisto Arcas, who was returning from a hunt at that time, saw a wild beast at the door of the palace and decided to kill him. However, at the last moment he was stopped by Zeus, who was not indifferent to the beauty. After being rescued, Callisto was taken to heaven. The stars of the Big Dipper bucket - this is it. At the same time, the supreme god raised the beauties to the sky and his beloved dog. Now she is known as 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 well-known constellations in this area. The reference point for finding one of them can be the same North Star. Behind it, on the opposite side from the Big Dipper, at approximately the same distance, flaunts the familiar to many by the name of Cassiopeia. Outwardly it looks like the Russian letter "M". At some positions of the Earth, Cassiopeia "turns over" and takes the form of the Latin W.
Between her and Ursa Minor, you can see not so noticeable, but also the well-known Clearly visible form, it does not have. Between Ursa Major and Ursa Minor, it is easy to see the wriggling Dragon. The chain of his stars is easily connected on the map with a broken line.
Well, we hope we have answered the main question of the article about how many luminous permanent objects there are in the Big Dipper. There are only seven of them in the Bucket. The main constellation includes about 125 distant "suns".
The constellation Ursa Major (Ursa Major) is seven particularly spectacular stars that are easy to find in the sky. These are stars of the second magnitude (the least is one - the top left star of the "bucket"). Excluding these stars, there are 125 more stars brighter than 6th magnitude in the constellation.
The size of the constellation Ursa Major
The constellation Ursa Major covers an area of \u200b\u200b1280 square degrees in the sky - this is one of the largest constellations. The constellation is much larger than the "bucket and handle" boundaries. Measurements have revealed, for example, that the stars of the "bucket" are located from us at rather unequal distances: the nearest star (Aliot) is at a distance of 50 light years from us, and to the most distant (Benetnash) is 4 times more. Near the star Mizar (which in Arabic means "horse") is located an almost imperceptible asterisk Alcor ("rider") of about the fifth magnitude.
Ursa Major in astronomy
Ursa Major can serve as a special "training ground" for novice astronomy lovers:
- this constellation, as a starting point, as a reference point, makes it possible to search for numerous other constellations;
- very clearly shows the apparent diurnal rotation of the firmament and the rearrangement of the view of the starry sky during the year;
- having memorized the angular distances between the stars of the "bucket", it is possible to carry out approximate angular measurements;
- astronomy lovers who have a barely perceptible telescope can view binary and variable stars inaccessible to the naked eye in the constellation Ursa Major and even distinguish some galaxies (including the famous "exploding galaxy" M82.
Constellation Ursa Major: myths and legends
The constellation "bucket" has been known to people since ancient times. The ancient Greeks believed that constellation Ursa Major - this is the nymph Callisto, companion of Artemis, beloved of Zeus. But one day she incurred the disfavor of the goddess, breaking the rules followed by the companions of Artemis. And she turned her into a bear and set the dogs on her. To protect his beloved, Zeus had to lift her to heaven.
Be that as it may, this event is dark: perhaps Zeus himself, hiding his own betrayals from the jealous wife of Hera, turned Callisto into a bear, and Artemis organized a hunt for her, either by mistake, or by teaching the sagacious and vengeful Hera. Perhaps, in the end, that Hera, for revenge, herself turned Callisto into a constellation, and the hunt for her was arranged by mistake by Callisto's son Arcad. From time to time, some unknown girlfriend Callisto is also involved in this story, at the same time turned into Ursa Minor.
Another myth, described by Philemon, says that the baby Zeus was forced to reincarnate into a snake, and turn his nannies into bears, when Father Cronus was looking for him in order, according to his habit, to eat the newborn. Ursa Major and Ursa Minor and the constellation Serpent came from this place. The constellation Serpent is not in the sky, probably - it is the Dragon. This is similar to the close location of all three constellations. However, this myth is perhaps just a poetic fantasy.
The constellation Ursa Major on the constellation map
You can also admire the Big Dipper during the day. This can easily be done by finding it on one of the interactive ones. On the maps, you can find other large and small constellations and look at them in large zoom. All in your hands!
Ursa Major (lat. Ursa major) - the constellation of the northern hemisphere of the sky. The seven stars of the Big Dipper make up a figure that resembles a bucket with a handle. The two brightest stars, Aliot 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. Best conditions visibility - in March - April. It can be seen throughout Russia all year round (except for the autumn months in southern Russia, when the Big Dipper 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 |
| Declination | from + 29 ° to + 73 ° 30 ' |
| Area | 1280 sq. degrees (3rd place) |
| The brightest stars (value< 3 m) |
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| Meteor showers |
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| Nearby constellations |
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| The constellation is visible in latitudes from + 90 ° to -16 °. Best time for observation - March. |
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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 by the astronomers of Egypt, Babylon, China and Ancient Greece. It was included by Claudius Ptolemy in his monograph "Almagest" in the II century. And this work united all the knowledge of astronomy at that time.
The Big Dipper is formed by the following seven stars:
- Dubhe (Alpha Ursa Major), the name comes from the Arabic expression - "the back of a big bear."
- Merak (β) - from Arabic "loin" or "groin" ..
- Fekda (γ) - "thigh".
- Megrets (δ) - “tail base”. It is the dimmest 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 one more star - "Alcor". It is noteworthy that the ability to distinguish between these two stars is a consequence of good vision (with myopia no more than 1 diopter).
- Benetnash (η) or otherwise - Alkaid. The third brightest star of the Big Dipper. "Al-Qaid Banat Our" is translated from Arabic as "the 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 bucket with a handle. Each star has its own name. At the top of the bucket, opposite to the handle, there is a star called Dubhe... She is the second brightest among her cosmic counterparts. It is a multiple star. That is, several stars from Earth are seen as one due to the close distance to each other.
In this case, we are dealing with 3 stars. The largest of these is the red giant. That is, the nucleus 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 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 a 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 because of the huge 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 the star of the Main Sequence. The upper point of the bucket located opposite it is called Megrets... She is the dimmest in a friendly company. This star is almost 1.5 times larger than ours and 14 times brighter.
There is a star in the initial part of the handle Aliot... She 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 is another luminary, which is called Alcor. Anyone with good eyesight can see it. They say that in ancient times, along Alcor, they tested the visual acuity of young youths who aspired to become seafarers. If a young man could see this star next to Mizar, then he was enlisted 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 the Earth, with the naked eye, you can see only a large bright point and a small one that is nearby. These are the surprises that space sometimes brings.
And finally, the most extreme star. It is called Benetnashor Alkaid... All these names are taken from the Arabic language. 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 luminary is the third brightest after Aliot and Dubhe. It ranks 35th among the brightest stars in the sky.
The brightest stars of the Big Dipper
| 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 \u003d 0.7 ″ AC \u003d 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 Α and Β |
| 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 | |
| μ UMa | 10 22 19,7 | +41 29 58 | 3,05 | M0III | 249 | 296 | cn. double? |
| ι UMa | 08 59 12,4 | +48 02 30 | 3,14 | A7IV | 48 | 10 | cn. double and wholesale. double |
| θ UMa | 09 32 51,3 | +51 40 38 | 3,18 | F6IV | 44 | 8 |
Other objects of the Big Dipper
In addition to the Big Dipper, in the constellation Ursa Major, you can also observe an asterism called "Three Jumps of a Gazelle", which looks like three pairs of stars.
These are the following pairs:
- Alula North South (ν and ξ),
- Tania North and South (λ and μ),
- Talita North and South (ι and κ).
Near Alupa Severnaya there is a red dwarf named Laland 21185, which is elusive for observation with the naked eye. However, it is the sixth closest star system to the Sun. Closer to the stars Sirius A and B.
Fans of observational astronomy are well aware that this constellation contains the galaxy M101 (called Pinwheel), as well as the galaxies M81 and M82. The latter two form the core of what is probably the closest group of galaxies located about 7 million light years away. Unlike these distant objects, the astronomical body M 97 ("Owl") is located within the Milky Way, hundreds of times closer. Owl is one of the largest planetary nebulae.
In the middle, between the first and second "leap of the gazelle", with the help of optics, you can see a small yellow dwarf, similar to our Sun at number 47. From 2000 to 2010, scientists discovered three exoplanets, gas giants, orbiting around it. Also, this star system is one of the most similar to the solar system and ranks 72nd in the list of candidates for the search for planets similar to Earth, conducted as part of the planned NASA Terrestrial Planet Finder mission. So for an amateur astronomy, the constellation is of great interest.
In 2013 and 2016, two of the galaxies farthest from us were discovered in the constellation, respectively z8 GND 5296 and GN-z11. The light from these galaxies, recorded by scientists, was 13.02 (z8 GND 5296) and 13.4 (GN-z11) billion years.
This is how you can characterize the constellation Ursa Major, known since ancient times. This space region also encompasses many galaxies. For example, the Pinwheel galaxy. It is better known as M 101. It is larger than the Milky Way in size. Its detailed pictures were taken by the Hubble telescope at the beginning of the XXI century. It takes 8 million light years to get to this huge cluster of stars.
The Owl Nebula is also of interest. It enters our galaxy and looks like 2 dark spots located nearby. In 1848 Lord Ross considered these spots to be like owl eyes. Hence the name came from. This nebula is about 6 thousand years old, and from the solar system it is located at a distance of 2300 light years.
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 named 47UMa. It is a yellow dwarf, and its planetary system is very similar to our solar system. At least, to date, 3 planets are known orbiting this star. In 2003, a radio message was sent to him. Earthlings are persistently looking for brothers in mind, and the stubborn are always lucky.
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's bucket. Although it is not far from the North Star, it is still not close enough to it to be at the same point in the sky all the time.
The Big Dipper is easiest to spot in autumn and winter. At this time, in the evenings, asterism is located in the north, not high above the horizon and in our usual position.
By the end of winter, the position of the Big Dipper in the evening sky changes. The seven stars of the ladle are shifted to the east, and the Big Dipper itself stands upright on the handle.
There is nothing surprising. Recall that every day all the stars describe circles around the pole of the world, reflecting the rotation of the Earth around its axis. But over the course of a year, the stars make another additional circle, thereby reflecting the movement of the Earth in its orbit around the Sun. The stars of the Big Dipper are no exception - moving from the bottom point, the bucket seems to rears up.
In mid-spring, the Big Dipper is at its zenith in the evenings, right above your head! At this time, he is in an inverted position in relation to the North Star. Her bucket faces west and her bucket handle faces east.
For those who live north of Moscow, the most difficult thing is to find the Big Dipper in the sky in the summer, during the period short nights... At this time, the constellation is in the west, and the bucket is tilted down and looks north.
How to find the North Star by the Big Dipper?
Now let's see how to find the North Star using the Big Dipper. This is done simply. Take the two outermost stars in the bucket, Dubhe and Merak (alpha and beta Ursa Major) and mentally connect them with a line. And then extend this line by five times the Merak-Dubhe distance.
You will see a star whose brightness is approximately equal to that of the bucket stars. This is the famous Polar Star, the "iron nail" as the Kazakhs called it, meaning the immobility of the Polar Star in the earthly firmament.
Knowing the position of the North Star, you can easily navigate in space. Draw a plumb line down from Polar. The place of its intersection with the horizon will point to the north. The rest of the cardinal points are easy to find: east will be on the right, south behind, 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 earliest astronomers in history, some of their round stone "observatories" dating back to the fifth millennium BC. It was the Egyptians who laid the foundations of the system of constellations, which the inhabitants of Mesopotamia, the Greeks, the Arabs, and then modern science borrowed from them. At that dizzyingly distant time, due to the precession of the earth's axis, it was not the North Star that pointed to the north, but the Alpha Dragon (Tuban). Its surroundings, together with the nearest luminaries, were considered by the Egyptians to be a "motionless sky", the habitat of the gods. Instead of a bucket, 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. Hawkeye Horus cut off his limb in revenge for the murder of his father.
China "Carriage of the Shandi Emperor"
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 annual rotation in Western astrology, which borrowed 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 had already taken its usual place by that time. The seven brightest stars of the Big Dipper are in an honorable proximity to it, within the Purple Fence - one of the three Fences that surround the palace of the "royal" star. They could be described as the North Bucket, orientated according to the season, or as part of the Heavenly Emperor Shandi's wagon.
India "Seven Wise Men"
Observational astronomy in ancient India did not develop as brilliantly as, say, mathematics. Her performances were greatly influenced by both Greece and China - for example, 27-28 "stations" (nakshatras), through which the Moon passes in about a month, are very reminiscent of the Chinese lunar "houses". The Hindus also attached great importance to the North Star, which, according to Vedic scholars, is the abode of Vishnu himself. The asterism of the Bucket located under it was considered the saptarish - 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 the 48 constellations listed in Ptolemy's star catalog around 140 BC, although it was first mentioned much earlier, even by Homer. Confusing Greek myths offer different prehistories for his appearance, although everyone agrees that the bear is the beautiful Callisto, the companion of the hunter goddess Artemis. According to one of the versions, using his usual tricks with reincarnation, the loving Zeus seduced her, causing the anger of both his wife Hera and Artemis herself. Rescuing 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 again. Preventing matricide, he lifted both of them to heaven.
America "Great Bear"
It seems that the Indians understood something about wild animals: in the legend of the Iroquois about the origin of asterism, the "heavenly bear" has no tail. The three stars that form the handle of the bucket are three hunters chasing the beasts: 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 kindle the hearth. In the fall, when the Bucket turns around and sinks low towards the horizon, blood from the wounded bear drips down, painting the trees in variegated colors.
- The closest of the bright stars of the Big Dipper– star South Alula or xi Big Dipper. It is a beautiful double star that can be split into components with a telescope with a lens over 80mm. Both components are similar in their characteristics to the Sun and each of them also has a companion - a cold 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. And farthest from the bright stars of the constellation is the red giant μ Ursa Major, one of the stars in the front "paw" of the Dipper. The distance to it is 249 light years.
- The constellation Ursa Major is depicted on the flag of Alaska. The flag of the 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 radical left organizations.
- You can also admire the Big Dipper during the day. This can be easily 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 in large zoom.
- Needless to say that the huge constellation Ursa Major is a real treasure for a true lover of astronomy ?! In this area of \u200b\u200bthe sky, there is a huge number of attractions available for observation with small telescopes: binary and variable stars, several bright galaxies and dozens of weaker galaxies, an open star cluster, and even a planetary nebula. There is no way to fit the descriptions of these objects into one article. Therefore, we decided to publish separate articles on the observation of the sights of the Big Dipper.
The constellation of this month is familiar to any inhabitant of the Northern Hemisphere. Throughout history, the Big Dipper has been an easily recognizable figure in the night sky. She seemed now a bear, now a plow, and three hunters with a bear and a bear with a cart were recognized in her. (Did I forget to mention that she looked like a bear? :-) In the asterism - the Big Dipper - they guess, probably, the largest number of figures for the night sky. The bucket serves as a reference point for finding many of the constellations of the Northern Hemisphere, and is itself an open cluster. It is designated as Collinder 285, or the moving group of stars of the Big Dipper, includes the five central stars of the Dipper and is located only 70 light years from Earth. Cr285 is best viewed with the naked eye.
| Name | A type | The size | Sound led | |
| Objects | NGC 2841 | Galaxy | 8.1 "x3.5" | 9,3 |
| NGC 2976 | Galaxy | 5.9 "x2.7" | 10,1 | |
| M 81 | Galaxy | 24.9 "x11.5" | 7 | |
| M 82 | Galaxy | 11.2 "x4.3" | 8,6 | |
| NGC 3077 | Galaxy | 5.2 "x4.7" | 10 | |
| IC 2574 | Galaxy | 13.2 "x5.4" | 10,2 | |
| M 108 | Galaxy | 8.6 "x2.4" | 9,9 | |
| M 97 | Planetary nebula | 2,8 | 9,9 | |
| NGC 3718 | Galaxy | 8.1 "x4" | 10,6 | |
| NGC 3729 | Galaxy | 2.9 "x1.9" | 11 | |
| NGC 3953 | Galaxy | 6.9 "x3.6" | 9,8 | |
| M 109 | Galaxy | 7.5x4.4 | 9,8 | |
| Cr 285 | Cluster of stars | 1400" | 0,4 | |
| M 101 | Galaxy | 28.8 "x26.9" | 7,5 | |
| NGC 5474 | Galaxy | 4.7 "x4.7" | 10,6 | |
| Complex objects | Hickson 56 | Cluster of galaxies | 14,5 | |
| Hickson 41 | Cluster of galaxies | 13,9 |
Ursa Major (BM) has several famous stars that are not part of the Bucket. It contains Lalande 21185 - a red dwarf with a magnitude of 7.49, which is the fourth star closest to the solar system and is located only 8.1 light years away. Lalande 21185 is the brightest red dwarf seen in the Northern Hemisphere. BM is also home to the 6.45 magnitude star Groombridge 1830, which is 28 light years away and travels at the third fastest speed of any known star. Groombridge 1830 is a class II star and is no less old than many globular clusters. Another famous star in the Big Dipper - 47 Big Dipper, which is one of the many sun-like stars and may have inhabited planets.
There are a total of 7 Messier objects in Ursa Major, 6 of which are of visual interest. (We will discard M40, although binary observers may want to look at it.)
In Ursa Major, the first ultra-deep image of the Hubble was taken, Hubble Deep Field: 12: 36: 49.4000s + 62d 12 "58.000". This tiny window (like a grain of rice at arm's length) allowed the Hubble telescope to look beyond our galaxy and catch at least 1,500 galaxies with a 10-day exposure. Almost everything you see in the image below is galaxies. (If you have high-speed internet, be sure to check "Hubble Deep Field" enlarged view.)
Before we head any further, let's take a closer look at the stars that make up the Bucket. If you start with the handle, here is Alkaid, then at the bend of the handle - the double Alcor and Mizar visible to the naked eye. Going down the ladle below, we get to Aliot, and a little further we find the first of the stars of the ladle itself - Megrets. Below, we first come across Fekda, then Merak and Dubhe. One of the first things any beginner learns is to draw a line through Merak and Dubhe to find the North Star, the northern star of the Ursa Minor.
I have read in various sources that many civilizations and cultures use Alcor and Mizar as a test for visual acuity, but this puzzles me a little, since I myself have never found it difficult to separate them.
Quite frankly, Ursa Major is a daunting constellation to write a guide to: it's gigantic and holds a dozen targets even for an observer with the most modest telescope. So I focused on those objects that I myself consider the brightest and most exciting. But I left one area aside - Walter Scott Houston called it the "goblet of the night" - the Ladle bowl itself. After completing this month's tour, I recommend that you take a little time and look at the area inside the bowl: several targets are suitable for a medium telescope. I will provide you with a search map, and at the end of the article you will find a list of the bright galaxies in and around the bowl.
We will start the evening tour at the bottom of the bowl, on the line between Fekda and Merak. Exactly southeast of Thecda (the stars are on the side of the bottom closer to the hilt), we find the first Messier target for today: M 109.
Discovered by Meschen, M 109 was known to Messier, but did not appear on “his” list until the middle of the 20th century. The original Messier list consisted of 103 targets, including several dubious ones (M40 is a double star, and the "missing" Messier is M 102).
M 109 Photographer Jason Blaschka
Photograph of M 109 by Jason Blaschka is striking, but not very similar to what I see even in the largest telescopes. Several features: even in a 4-inch apochromat (under a good sky), the galaxy has a noticeable resemblance to a TIE-fighter - the central bar is often visible, but on a rare night I can catch a hint of spiral arms through a small aperture.
Jay Michaels made an excellent sketch - a great example of what can be seen with an 8-10 inch telescope on a good night. While you're here, take some time to search NGC 3953, about a degree south of M 109. Then move to the middle of the bottom of the bowl, go down a little further south and you will find a pleasant cluster of objects - NGC 3718,NGC 3729 and one of the challenging objects of this month Hickson 56.
With an average magnification 3718 and 3729 are in the same field of view. I would say that 3718 is about three times the size of 3729, but in my opinion the galaxies are quite similar to each other. In large telescopes, I see that both have noticeable (albeit faintly) cores and scattered outer halos. A little further south you will find Hickson 56 - but we'll come back to it later.
Move towards the star at the base of the bucket (Meraku) with a low power wide-angle eyepiece and you will stumble upon a random celestial pair. First, there will be M97 - owl nebula, a planetary nebula discovered by Pierre Mechein in 1781. I believe this is one of the few objects that actually resembles their nickname. Even in a small telescope (under good conditions), I can fleetingly catch the outlines of dark spots - owl's eyes. The nebula is quite large, so its surface brightness is rather low. Some observers claim to have seen blue or green on the surface of the disc. On a superb observational night, I captured shades of green with a large telescope, but usually the disc looks just gray.
Rick Krejecki's M97 shot is amazing. Take a look at the higher resolution version on his website (http://www.ricksastro.com/DSOs/owl_XT_xscope.shtml) - you can spend a lot of time just counting tiny background galaxies. I wonder if at least one of them was visually identified by observers with giant telescopes?
If you have a desire to look at extragalactic targets, you don't have to go far - a little closer to Merak you will find a spiral galaxy M 108located with an edge to us. Experiment a bit with different magnifications - see if you can discern the mosaic structure and if you can detect any presence of an outer halo.
An excellent shot of Tom Nicolades in one shot shows a shattered and wobbly electric blue M 108 and M 97. With a low magnification wide-angle eyepiece (the field of view of the telescope + eyepiece system, TFOV, must be greater than 1 degree), both objects can be easily caught in the same field of view.
While we're here, let's jump over the Dipper's front legs and take a quick look at NGC 2841... This 9.2 magnitude galaxy is like a ray of hope for medium-sized telescopes. The bright region of the core is surrounded by a slightly dimmer halo. If you have a large telescope, look for a strip of dust, i.e. a sharp decay of a halo on one side of the galaxy.
M 81 / M 82 - Photographer John Moody
Having finished with 2841, let's move on to a pair of real pearls of the Big Dipper, M 81 and M 82.
M 81 and 82 make up an exciting pair of galaxies that can be seen even with small binoculars. They are separated by only 3/4 degrees, are visible through wide-angle eyepieces and make a wonderful pair. They were discovered by Bode in 1774 and are an illustration of galactic morphology, which at first glance does not allow much difference. Both galaxies are members of a small cluster of galaxies called group M 81 (which is nearby, 10 million light-years away), so it would be appropriate to discuss M 81 first. In small telescopes, M 81 is a bright oval, but large telescopes are starting to show it spiral structure. Of the two, M 81 is by far the larger and brighter, and in long exposure photos it looks like a classic spiral galaxy. The M 82, by contrast, is twisted incorrectly and looks like it has been defeated in some kind of huge heavenly conflict. With an 18-inch telescope, I can see it curved at one end, there is a distinct spotting, as well as an almost clear partition about a third of the way from one of the edges. It is slightly dimmer than the M 81, but visually I find it much more impressive.
It is worth noting that this is one of the few DSOs in which visualists observe color, but not even with 80mm telescopes yet. A friend of mine in Arizona with access to a 30 "telescope describes seeing red or pink, and I don't see anything like that, although I observe this object with telescopes up to 25" in diameter. I think it will require an excellent night, good optics, and the maximum aperture you can afford.
But don't despair! In my opinion, the M 82 is one of the most beautiful targets in the night sky, with or without color. Even in small telescopes, the pair is stunning and can be distinguished against dark skies with minimal optical aid.
Carol Lakomiak's sketching of this area gives an excellent idea of \u200b\u200bwhat can be seen with large binoculars or a small telescope.
As you can see from the map, there are many other targets in this region. Take some time and scout everything around - watch out for NGC 3077, 2976 and IC 2574... In my opinion, NGC 3077 and 2976 in large telescopes are similar in brightness to M 81 in small apertures. If you use the "star trail method" in your search for M81 and linger on one of them, embarrassment can occur. Your expectations should always match the aperture.
We have not even begun to really reveal the possibilities of the Big Dipper, and yet we will make one more stop, and then move on to two difficult objects.
Go around the top of the Bucket and continue away from the handle to find M 101 - galaxy Spinner (Pinwheel) *. It was discovered by Meschen in 1781 and looks really spectacular in a large telescope, showing an obvious spiral structure and spotting in the arms.M101 has a large, loose surface, which can be confusing and difficult to observe with a small telescope. Remember when looking for this large object: it is about 2/3 of the full moon, but the surface gloss is very low, so be vigilant and gradually make it stand out from the background. The galaxy is huge - directories indicate between 170,000 and 190,000 light years across. It is roughly 25 million light-years distant and includes some of the most spectacular and largest known star-forming regions.
Many of these stellar maternity hospitals are bright enough to merit their own NGC numbers: NGC 5441, 5447, 5450, 5449, 5451, 5453, 5458, 5461, 5462, and 5471.
NGC 5471 is the largest and brightest HII region in M101, much larger than anything comparable in the Milky Way (5471B is assumed to contain a hypernova). It is visible with large telescopes, and although I often recommend viewing galaxies at high magnification (my favorite "galactic horse" - the Nagler 13t6 eyepiece and the Obsession 18 ”telescope - provides about 180x magnification and a good wide field of view), the detailed structure of M101 I'd rather advise you to do some research at high and low magnifications and determine what works best for you personally. Be sure to take a look at the brightest HII areas. Note that the image below does not capture 5450 and 5447 - 5447 is located south of 5450.
Region HII. Galaxy M 101
Like M81, M101 is the main member of the group of galaxies of the same name, so while you are in this area, keep a close eye on the other rogues. The brightest are NGC 5474 and NGC 5473, but there are many others here.
M101. Photographer James Jacobson
Complex objects There are several objects in the Big Dipper that deserve to be called complex. The first things that come to mind are the 7 Hickson groups, the globular cluster Palomar 4, and a rather bright quasar. Quasars are interesting on their own, and not because of what you see in the eyepiece, and Palomar 4, of course, can be dealt with with a large telescope and in dark areas, so in general I lean towards the group of galaxies. Considering the above, I present two "brightest" Hicksons in the Big Dipper as complex objects: Hickson 56 and Hickson 41.
Hickson 56 lies exactly south of the pair of galaxies we visited earlier - NGC 3729 and 3718.
Notice that the marker that marks the position of Hickson 56 is slightly offset in the image above. The Hickson 56 has 5 components (although not all of them can be seen), whose luster ranges from 16.2 to 15.8, and they are all tiny (the largest takes 1.3x2 arc seconds), so be sure to grab them with good conditions and with a large aperture.
Iiro Sairanen from Finland observed Hickson 56 with 16 '' Newton at 292x and provided the following sketch:
Another complex object of the month - Hickson 41.
Hickson 41 is a little harder to get to, but slightly brighter. Again, note that it does not perfectly match the above cards. Rely on DSS images. There are 4 components, ranging from 14.6 to 18.1, with the largest element measuring just 1.5x2 arc seconds. Alvin Huey, observing at 377x and 528x, wrote in his excellent Hickson Group Observer's Guide that he failed to capture the fourth member in the 22 ”f4.1 Dobson.
I was able to catch three of these four galaxies with 18 ”f4.5 from my driveway, but it took some tweaks - it took a good evening, I covered my head with a towel to get rid of extraneous light and used very high magnifications (600x). to darken the sky background sufficiently. Finally, I had to resort to tapping the telescope to make sure I tracked down all three members of the group. The Hicksons, for the most part, are not casual sightings or objects for a quick glance. To get a glimpse of these tiny groups of interacting galaxies, use every trick in the book, including high magnification and tenacity. Additional Objectives
As I wrote above, Walter Scott Houston called this area “the cup of the night”. Here's a map that may give you some more reasons to travel on the bucket bowl.
And this is the necessary information about additional goals:
* Help from Wikipedia: The Russian name Tsevochnoe Wheel is the result of an incorrect translation from English. The lantern is used in gear drives, it resembles a squirrel wheel of two parallel rims, connected by pins (pins); in English, both a pinwheel and a spinner (breeze) (a children's toy, a multi-bladed impeller mounted on an axle (pin) and spun by the wind) are denoted by the term pinwheel, but in appearance the galaxy with its spiral arms looks like a pinwheel, and not pinwheel.
Until next time,
Tom T.
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Jupiter and Callisto. Francois Boucher, 1744 Moscow, Museum of Fine Arts. AC. Pushkin |
Description
Ursa Major is the constellation of the northern hemisphere of the sky, its seven stars make up the most famous figure in the sky. This is a bucket, which with its two extreme stars Dubhe (α Ursa Major, 1.8 m) and Merak (β Ursa Major, 2.3 m) gives direction to the North Star.
The brightest star is Aliot (ε Ursa Major, 1.76 m), and the most famous binary system is Mizar (ζ Ursa Major, 2.2 m) - “horse” and Alcor (80 Ursa Major, 4 m) - “rider ". It is believed that whoever distinguishes between these two stars has keen eyesight.
In the constellation, two spiral galaxies M81 (7.0 m) and M101 (7.9 m) are visible, which can be observed with a small telescope. M81 is interesting in that it is very similar to our Galaxy. Nearby is the small galaxy M82, in which a powerful explosion took place just a few million years ago. This event is of great interest for astronomy, as it sheds light on the formation and development of galaxies.
Another interesting object is located in Ursa Major - the planetary nebula M97 - "Owl", which got its name for its resemblance to this bird. It can be observed with a small telescope, since the total brightness of the nebula is 11 m.
Most interesting objects
Star ζ Big Dipperis a system of six stars. Of these, only two - Mizar and Alkor can be seen with a simple eye... The distance between these stars is 11 ". Mizar is a binary star that can be clearly seen in a small telescope. The distance between the components is 14.5" ". These two stars, as well as Alcor, are spectroscopic binaries. The distance of the entire system from the Sun is about 60 sv. Years.
Star U Big Dipperis a typical eclipsing variable, the components of which are in the Roche lobe. The brightness change period is 8 h, and the maximum brightness is 8.7 m.
χ Big Dipper- a multiple system consisting of two spectroscopic binaries at a distance of 2.5 "". Orbit around a common center of mass in 60 years. The most massive pair consists of stars similar to the Sun, and the second consists of the same star and an invisible companion with a mass 10 times less than the Sun. The entire system is removed from the Sun at a distance of 25 s. years old.
M40- a faint double star discovered by Charles Messier in the place where he wanted to find the nebula, mistakenly described by Ian Hevelius. Located near the star 70 Ursa Major. The system consists of two stars of magnitude 9.0 m and 9.3 m, located 49 "" apart from each other. The brighter star is located at a distance of 510 s. From the Sun. years old. Most likely, this is an optically double star, i.e. its components are not connected physically, but are located close along the line of sight.
M97- planetary nebula "Owl". Has a brightness of 9.9 m. The mass of the nebula is approximately 0.15 solar masses. There are about 6 thousand years. Removed from the Sun at a distance of 12 thousand sv. years old.
SU Big Dipper- a variable eruptive star of the type of dwarf novae, in which two types of flares are observed. The system consists of a white dwarf surrounded by an accretion disk and a cold component of lesser mass. At the minimum brightness, this star is no brighter than 15 m. During ordinary flares, which occur every few days, the brightness increases to 12 m, and during more rare bursts - up to 10.9 m.
M81is a beautiful spiral galaxy of the Sb type. Brightness 6.9 m. Paired with it is the galaxy M82 - irregular in shape and weaker. Being more massive, M81 deforms its neighbor with its gravitational field. The Hubble Space Telescope has made it possible to study 32 variable stars - Cepheids in M81. Using this information, its distance to the Galaxy was determined - 11 million sv. years old.
Spiral galaxy M81 (left) and irregular galaxy M82 (right). Composite images from ground and space imagery.
M101- NGC 5457 is a 22 "Sc type spiral galaxy. The brightness is 7.9 m. The central part of this galaxy is visible in small telescopes. Photos taken with large telescopes show that it is asymmetric. The galactic nucleus is far from the center of the disk. Distance to M101 was determined by the Hubble Space Telescope with the Cepheids and is approximately 24 million light-years The linear diameter of the galaxy is about 170 thousand light years.Three supernovae were observed in this star system in 1909, 1951 and 1970.
Research history
In 1603, a significant event took place. The German astronomer Johann Bayer (1572-1625) published his famous atlas "Uranometry", which significantly clarified the position of the stars in the sky. In it, he first designated the stars in Greek letters, including the seven bright stars of the Big Dipper Bucket from west to east in the "direction" of this star pattern. In doing so, Bayer violated the rule that the brightness of the stars must correspond to the Greek alphabet. The alpha star is the brightest, the second brightest is the beta, and so on. The basis for "Uranometry" was the observations of the Danish astronomer Tycho Brahe.
The most popular constellation, probably familiar to every person. It looks like a bright spectacular bucket and is observed throughout the year, since it is located near the North Pole of the world and belongs to the constellations that do not set in the northern latitudes. The constellation is named after the nymph Callisto.
Observation
Ursa Major is one of those constellations whose location is well known. In fact, this constellation is the first to get acquainted with, since the Dipper's dipper is a very characteristic figure. East of the Big Dipper, Perseus and Cassiopeia are clearly visible across the sky. The constellation Giraffe adjacent to the Big Dipper does not have bright stars and it is difficult to navigate by it. Bootes and its bright star Arcturus, located to the southeast, are catching up with the bear.
The best visibility is in March and April. The constellation is clearly visible throughout Russia.
Mythology
According to the ancient myth, the forever young goddess of the hunt, Artemis, roamed the mountains and forests with a bow and a sharp spear in search of game. Her companions and maids followed her. The girls were one more beautiful than the other, but Callisto was the most charming. When Zeus (in Roman mythology, Jupiter) saw a nymph, he was amazed at her beauty and youth. However, the maids of Artemis were not allowed to marry. To take possession of Callisto, Zeus went for a trick, and one night he appeared before her in the form of Artemis. Thus Zeus achieved his goal. From Zeus, Callisto gave birth to a son, Arcade, who quickly grew up and became an excellent hunter.