Astronomy. Constellation Andromeda: legend, location, interesting objects

Despite the gigantic distance to (amounting to 2.54 million light years), it still has an apparent magnitude of 3.44 and a linear size of 3.167 × 1° at starry sky, which allows you to observe it naked eye in the sky like a slightly oblong spot. This is achieved by the fact that Andromeda contains about a trillion stars (thus exceeding its size by at least 2.5 times and being the largest galaxy in the Local Group). However, despite huge number stars in it, it is still inferior in brightness to about 150 stars in both hemispheres of the starry sky.

Observation

The Andromeda Galaxy is located in the constellation of the same name, but it is best to start searching for it from the one that is easier to find and move through the constellations or.

Pegasus constellation : in this case, in the continuation of the constellation Pegasus, we will need to find Alferaz (the brightest star of the constellation Andromeda) from which we need to move to Mirakh, from which we turn 90° and look for two other bright stars of this constellation. A little further on, the second of these stars will be Andromeda.

Constellation Cassiopeia : another way to find Andromeda also starts from the North Star, but in this case we should find the constellation Cassiopeia, which looks like the letter M or W in the sky, depending on its current position. On the continuation of the Polaris-Shedar line (the 2nd star on the right of this constellation), a little further than half the distance between them will be the Andromeda Galaxy.

Observation history

Since this galaxy is visible to the naked eye, the first mention of it dates back to 946 AD. But before the advent of modern multi-meter telescopes, it was impossible to distinguish individual stars in it, so the true nature of this object was hidden from observers under the guise of a small nebula in our galaxy. The first signs of its extragalactic origin were obtained through spectral analysis, made in 1912 (it turned out that it was moving in our direction at a speed of 300 km/s) and a supernova explosion registered in 1917 (which gave the first approximate value of the distance to it - 500 thousand light years). However, only Edwin Hubble managed to put a final point in the dispute between scientists.

Andromeda is a constellation that can be seen in the northern hemisphere of our planet. It has three stars of the second magnitude in its arsenal. A constellation has a characteristic pattern created by the stars included in it. The chain of these luminaries stretches from the northeast towards the southwest.

The constellation Andromeda is very clearly visible throughout Russia. You can watch it almost all night, because the constellation is located high in the sky. It is best observed in October and November, but you can start in September.

Finding the Andromeda constellation itself is not difficult. First of all, you need to find the Great Square of Pegasus. In the northeast corner of this square is a star called Alpheraz. It is this luminary that is the beginning of Andromeda. The constellation occupies approximately 722 square degrees in the sky.

Where is M31 located?

On a moonless, dark and cloudless night, about 160 stars can be observed in the constellation with the naked eye. These are luminaries that have a brightness of up to 6.5 magnitudes.

Overview of the Andromeda Nebula Galaxy or M31

Among all the objects in the constellation, you can see the most remarkable one - the spiral galaxy or M31.

Andromeda Galaxy or M31 in the UV range

Galaxy M31 was noticed by astronomers back in the 10th century, but its true nature was revealed only in the 19th, with the advent of powerful telescopes. Andromeda also contains variables, star clusters, planetary nebulae, dwarf galaxies and other interesting objects.

What M31 looks like through a telescope

Stars

Almak is a system that consists of three objects. The main one is a yellow star, which has a brilliance of the second magnitude. There are two satellites around it: blue stars are physically connected.

Alferats - has a magnitude of 2.1 magnitude. Refers to navigation (like Almak). Using them as a guide, ancient sailors found their way home.

R Andromedae is a variable star. It has a brightness variation amplitude of nine magnitudes.

υ Andromeda is a main sequence star in which astronomers discovered a planetary system. Planet b is similar to Jupiter. The other two are eccentric giants.

Galaxies

The Andromeda Nebula is the most famous galaxy. It was observed by a Persian astronomer back in the 10th century. It has satellites - small galaxies M32 and NGC 205.

Dwarf elliptical galaxy M32, satellite of the Andromeda Galaxy

The nebula is easy to see on a moonless night with the naked eye. It has a diameter of approximately 220 thousand light years. It contains more than 300 billion stars. This closest spiral galaxy is 2.2 million light years away from us. Within the nebula itself there are many globular clusters. Starting with M32, systematic observation of galaxies began. Special significance The Hubble telescope was used in these observations.

NGC 891 is the most impressive galaxy. It is located edge-on to us and looks very beautiful.

NGC 891 seen through a telescope

In addition to the galaxies, there is a planetary nebula called NGC 7662 and a star with the exoplanet WASP-1.

Collision of the Milky Way and M31

At the moment, the two largest galaxies, the so-called local cluster, are ours and M31. We are moving towards each other and in a few billion years both of our galaxies will merge into one large one. This will be a grandiose spectacle of universal proportions. Astronomers have even modeled what this merger would look like.

Story

The constellation is included in the Almagest and is the most ancient. Greek myth talks about the beautiful princess Andromeda, who was given to King Kefei to be devoured sea monster. She was freed by Perseus, and after her death the gods placed her in the starry sky.

M31 "Andromeda Nebula".
11/28/2010, Deepsky 80\560ED telescope, WO 0.8x II gear-corrector, Canon 1000D, ISO 1600, shutter speed 1 minute, 10-15 frames. Mount - EQ5

How to find the famous Andromeda Nebula (M31)? Best time The best time to observe it is in autumn, but you can also try to find it at other times of the year (for example, in the morning in summer). To search, you must first face the northern part of the sky and find the constellation Ursa Major, draw a line from the handle of the “bucket” through the North Star, and on the continuation of this imaginary line you will see an inverted letter M or W - this is the constellation Cassiopeia. Cassiopeia - pretty bright constellation, so you can find it easily.

Then we turn to the right, to the southeastern side of the sky - we see that under Cassiopeia there are two large constellations - Andromeda and Pegasus. Feature- the so-called “Pegasus Square” - four stars forming a kind of “square”.

We will orient ourselves from it - draw an imaginary line along the stars, first to the left and then up. If you did everything correctly and look at the desired location through binoculars, a telescope or a good optical finder, you will see a small light oval cloud. Congratulations, this is the Andromeda Nebula - a huge galaxy with which our Galaxy is approaching (the collision will occur in 3-4 billion years).

In small telescopes it is visible in the same way as in binoculars/spotting scopes, but larger - a large oval spot. Several of its satellites, small galaxies (M32 and M110), also become noticeable. With 20x60 binoculars, it is visible throughout the entire field of view. The visual size of the Andromeda Nebula is about 3...3.5 degrees - 7 times the apparent size of the Moon! In telescopes of larger diameters (from 250 mm and more), dust paths near the center of the galaxy become accessible for observation.
The main key to success in observations is a dark sky and the absence of flare.

In the photographs, the Andromeda Nebula looks much more beautiful than visually, primarily due to the visibility of dust clouds along the center of the galaxy. Basic images of the galaxy can be obtained with even the simplest motorized equatorial mount and a DSLR camera with a kit lens.

Cold autumn evening... Distant stars tremble and twinkle above the tops of yellowed trees. In the south you can see the Great Summer Triangle - the three brightest stars. But its time passes: closer to midnight, the triangle approaches the horizon, and on the southern slope the place is occupied by a large bucket of the constellations Pegasus and Andromeda.

For more than two thousand years, since the times of Hipparchus and Eratosthenes, the constellation of the autumn sky Andromeda has been flickering brightly among a scattering of distant stars.

Legend of the constellation Andromeda

At a time when magic ruled the world, during the era of the gods of Olympus in far away country King Cepheus ruled under the name Ethiopia. He had a wife, Cassiopeia, and a daughter, Andromeda.

And everything would be fine in the country of King Cepheus if it were not for the boasting of his lovely wife Cassiopeia. Once the king’s wife boasted that she was more beautiful than the Nereids and nymphs. The sea beauties heard about this. The resentment overflowed, and they complained to the god of the seas, Poseidon. Being his daughters and granddaughters, they understood that he would listen to them and would not leave the terrible insult unpunished.

Then Poseidon became angry and sent scary monster. The Terrible Whale constantly came out of the sea and destroyed the country. Then King Cepheus was saddened, having learned the whole truth from his wife, and went for advice to the oracle of Zeus. He listened to him and advised him to give his daughter Andromeda to the monster - Keith, in order for peace to come in the country. But how could you sacrifice your own daughter? In complete confusion, Cepheus wandered home. After some time, the people learned about the oracle's advice and forced the king to resolve this issue.

Pay

Andromeda, chained to a rock, awaited her death with horror.

But suddenly Perseus suddenly appeared, having learned the whole truth, he began to wait for the monster to fight him.

Happy ending to the story

As in any good mythical legend, good triumphed over evil.

But there were some incidents. Andromeda was betrothed to Finney, brother of Cepheus. He appeared at the wedding of Perseus and Andromeda and demanded the return of the bride. But Perseus was not going to give up the beautiful bride. He took out the head of the Gorgon Medusa and turned Phineus into stone. This is the story of the times of magic and the gods. And we will involuntarily remember her, watching in the sky how brightly Andromeda flickers - the constellation, the legend of which is so beautiful and instructive.

How to find Andromeda in the sky?

After reading interesting legend, most likely, you will want to see Andromeda with your own eyes. It's not difficult to find. The easiest time to spot the constellation is in the fall. Between September and early December, the constellation Andromeda can be seen from early twilight until morning. In the evening, the asterism is in the east, a little closer to midnight - in the south. Closer to the morning it moves in a westerly direction. First you will need to find a giant quadrangle - the Pegasus Square.

To the left of the Square you can see a chain of stars of the same luminosity. These are precisely the stars of the Andromeda constellation.

You can find the desired asterism in another way. First, find the constellation Cassiopeia, it looks like the letter M or W, depending on the position of the asterism in the sky. The Andromeda stars are located directly below this “letter”. With the onset of December, the constellation Andromeda shifts to the west. Closer to spring, the asterism is already in the northwest direction. And with the approach of summer, it comes out only at dawn, and it is quite difficult to notice it.

The city lights are fading and the stars are shining

Of course, even for a person with a rich imagination it is difficult to imagine a girl looking at the “handle” in the sky. However, these three stars are not the entire constellation - Andromeda (photo below) occupies much large area in the sky. On the northern side, the asterism is bordered by the constellations Pegasus and Cassiopeia, on the south by the Triangle and Pisces, and on the west by the Lizard and Pegasus.

However, to see all the stars of the Andromeda constellation, you will need to travel outside the city limits, where there is no night lighting. Once you get used to the darkness a little, you will be amazed at the huge number of stars in the sky that are visible to the naked eye. Take a look at our constellation Andromeda - Alpha Andromeda forms the upper left corner of Pegasus Square - the girl's head. The following objects δ, σ and θ form Andromeda's shoulders, β, μ and ν constellations form her waist. Other objects are γ and M51 Andromeda - her legs. The girl's hands are marked with stars λ on one side and ζ on the other.

You see that the girl’s arms are spread out to the sides. Why? The answer is obvious: she is chained to a rock. If you look closely, the Andromeda constellation really resembles the figure of a girl chained to a rock.

Taking a walk away from the city lights, you saw how the “handle” took on the shape of a girl from an ancient legend.

Some terms in simple language

It may be a little difficult to remember or understand some of the description.

We will explain to you in simple language Some terms and expressions used in the article:

Giants are stars much larger than our Sun (which is a yellow dwarf).
Temperature in Kelvin is 273 degrees higher than Celsius (0 degrees Celsius translates to 273 degrees Kelvin).
A light year is the distance that light travels in one year (for example, light travels from the Sun to Earth in 8 minutes 19 seconds).
Often referred to as "spectral class" - scientists determine the temperature of a distant star using a certain spectrum (like a rainbow with different widths of bands of all colors).
The stars of constellations (objects) are designated, starting with the brightest, using Greek alphabet: α, β, γ and so on. They may also have a separate name. For example: Alferats or α Andromeda.

Constellation Andromeda: description of stars

Let's start with the brightest star of our asterism.

Alferaz is the brightest star in the constellation Andromeda, with Arabic translated means “navel of a horse.” From antiquity and the Middle Ages to the 17th century, this star belonged simultaneously to two constellations - Pegasus and Andromeda.

Alferaz is a blue subgiant with a temperature of 13,000 degrees Kelvin. emitting light 200 times larger than the Sun. It is located 97 light years from Earth. A study of the spectrum showed that Alferaz is a pair star. She is considered a prominent representative amazing class mercury-manganese stars.

Their atmosphere may contain an excess of europium, gallium, mercury and manganese, and the proportion of all other elements is insignificant. Scientists suggest that main reason The anomalies may be strongly influenced by the radiation and gravity of the star.

β constellation Andromeda - Mirax, a fairly large object, belongs to the group of red giants.

Alamak - γ Andromedae, is the third brightest star in the constellation. This complex system, which consists of four bright components. Alamak is one of the beautiful double stars that can be observed even through a small telescope. Its main yellow star has a bluish companion and is considered a giant of spectral class K3. The object's temperature reaches about 4500 K. Almak's radius is 70 times greater than that of our star.

These are the main characteristics of the three most bright stars in the constellation Andromeda.

So where was the rock that Andromeda was chained to? This question was asked by many geographers of the past. According to Strabo, the rock was located in Iop, near the city of Tel Aviv. The Jewish chronicler Josephus (1st century AD) even claimed that imprints of Andromeda's chains and the remains of a monster could be found on the shore!

As for Ethiopia, it is quite far from Israel. Obviously, this rock was located on the shores of the Red Sea, and Andromeda herself was a black woman. True, according to Herodotus, all the events described took place on the territory of India. Definitely the question remains open. It is quite possible that the legend told about real events, but transformed into a kind of myth that has survived to our time.

(I hope that it’s successful), and now let’s try to find in it what, in fact, novice amateur astronomers are interested in this constellation for. We will, of course, talk about Andromeda Nebula. So, how to find the Andromeda Nebula in the starry sky?

The first thing to say before starting your search: The Andromeda Nebula is completely not a nebula, that is not a cloud of interstellar gas like the Orion Nebula, A a giant galaxy like our Milky Way and even more. According to recent estimates, the Andromeda Nebula contains about a thousand billion stars. About every 20th of these stars is similar in its characteristics to our Sun.

Why then was the Andromeda Nebula called that? This story stretches back to the times when astronomers called nebulae any faint, unclear object that could not be resolved into individual stars through a telescope, similar in appearance to a cloud or a piece of the Milky Way. Later it turned out that some of these objects were distant star clusters, some were indeed clouds of interstellar gas, and some were very distant huge galaxies. But the name common to all has stuck and is still used today, although it is quickly becoming outdated.

The Andromeda Nebula has official designations. The most famous - M31(object number 31 from the catalog of Charles Messier) and NGC 224(224th object from the “New General Catalog” of nebulous objects). So don't be surprised if instead of "Andromeda Nebula" you read "M31", "NGC 224" or "Andromeda Galaxy".

On nice photos The Andromeda nebula looks like this:

Andromeda Galaxy (M31). Equipment Asi 071, Takahashi Epsilon 130 telescope, total exposure 5.4 hours. Photo: Richard Sweeney

How What does the Andromeda Nebula look like in the sky? Depends on where, when and how you look at it. Three factors have the greatest influence on the quality of what is observed:

Sky flare. Cities have long turned into a citadel of light: street lighting is so bright that it successfully hid all faint stars from city residents, not to mention nebulae or Milky Way. In addition, smog often hangs over large cities, which well scatters the light of street lamps and turns even a cloudless sky into milk.
The height of the Andromeda Nebula above the horizon. At sunrise and sunset, the galaxy is difficult to observe, since atmospheric absorption of light is high directly above the horizon. Best conditions for observing the galaxy - August and September nights, as well as evenings in October, November and December when the galaxy is very high in the sky.
General condition of the sky. Even outside the city, far from street lighting, the sky can be unimportant. What is important is not the calmness of the atmosphere, but its transparency. The more transparent and clear sky above your head, the dimmer the objects you will be able to see on it.

Let's say you are outside the city, or at least on the outskirts of the city, and the sky above you is more or less dark and transparent. There are two ways to find the Andromeda Galaxy in the night sky.

How to find the Andromeda Nebula in the sky. Method No. 1

In the first method, the zero point of your search is a large quadrangle of stars called Pegasus square.

The Great Square of Pegasus and the constellation Andromeda adjacent to the square on the left. Pattern: Stellarium

On autumn evenings, the Square of Pegasus hardly needs searching - it will literally catch your eye if you stand facing south and raise your head up. The stars forming the square are not very bright - their brilliance is approximately equal to the brilliance of the stars of the famous Ursa Major bucket, but since the stars surrounding the square are also not bright, it literally dominates the picture of the evening sky in the second half of autumn.

Having found the square of Pegasus in the sky, you can easily find all the main stars that form the figure of Andromeda. Let me remind you that the main drawing of the constellation is a chain of stars extending from the upper left corner of the Pegasus square to the east, forming together with the square something resembling a giant smoking pipe and mouthpiece.

In November, Andromeda is very high in the sky in the evenings.

Now pay attention to the middle star in the chain. This is β Andromedae or star Mirakh. (Problems with Greek letters? Alphabet.) Above it you will see two rather faint stars - μ and ν Andromeda. All three stars together form Andromeda belt. (On medieval maps, the heroine of the ancient myth stands chained to a rock, but... for some reason in a horizontal position!) So, the Andromeda Nebula is located directly above the belt, above the asterisk ν Andromeda!

The Andromeda nebula lies directly above the star Nu Andromeda. Pattern: Stellarium

How to find the Andromeda Nebula in the sky. Method number 2

The second way is that we are looking for the Andromeda Nebula not from the square of Pegasus, but from constellation Cassiopeia, which is almost at its zenith on autumn evenings.

The constellation Cassiopeia is extremely easy to find thanks to its distinctive letter W(or M, as you like) which it forms in the sky. To see Cassiopeia in the fall, simply.

Found a constellation? Now notice that the right half of the celestial W is sharper than the left. This sharper half of the constellation is the arrow pointing towards the Andromeda Galaxy.

Use the right, sharper part of the W as a celestial arrow pointing towards the Andromeda Nebula. Pattern: Stellarium

The distance from the arrowhead to the nebula is about 4 times greater than between the neighboring stars that form the W of Cassiopeia.

Do you see it now?

What to do if the Andromeda Nebula is not visible?

If the Andromeda Nebula is not visible to the naked eye, you can try to find it with binoculars or a telescope.

Binoculars provide a larger field of view, making it easier to look for the galaxy through them. Start your search from the star Mirakh (beta Andromeda), then point your binoculars through mu and nu Andromeda. In the city sky, the nebula will appear through binoculars as an indistinct spot slightly above and to the right of Andromeda. Explore this area of the sky slowly. Only outside the city will the smooth, soft glow of the galaxy begin to catch your eye.

In a telescope, the search must also be carried out from the star Mirakh sequentially through the mu and nu of Andromeda. When searching, use the lowest magnification possible to maximize your field of view. In general, large magnifications are useless for observing galaxies and faint nebulae - they reduce the contrast. Newton owners, be aware that your telescopes produce an upside-down image! Those with Go To telescopes can simply type the name of the nebula into the computer and the telescope will point at it automatically.

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