Andromeda is the galaxy closest to the Milky Way. Collision of the Milky Way and Andromeda

The Andromeda Galaxy, known by several names: the great Andromeda nebula, also known as the Andromeda spiral galaxy, also known as Monsieur 31 (M31) in the astronomical classification of galaxies, has long been a source of inspiration for astronomers, science fiction writers, and, for some time, for computer game developers . After all, just recently an excellent sci-fi game appeared - Mass Effect Andromeda, just about a hypothetical flight of people of the future to our neighboring Andromeda galaxy. Yes, that's right, Andromeda is a neighboring galaxy to ours Milky Way, and moreover, the closest to us big galaxy. But, nevertheless, despite this, the distance to the Andromeda galaxy from Earth is not so small, it is 2.5 million light years. That is, the glow we see from Andromeda in the night starry sky came out from its source 2.5 million years ago.

History of the discovery of Andromeda

The Andromeda Galaxy has been known to us since ancient times; it was first noticed by the Chaldean priests and also excellent astronomers. ancient world. The ancient Greeks also knew about it, because it was thanks to them that the galaxy got its name. Andromeda, the heroine of ancient Greek myth, was the daughter of the Ethiopian king Kepheus. As punishment for Kefei's boasting, the god of the seas Poseidon (aka) ordered the king to sacrifice his daughter to the sea monster Kraken, otherwise the entire kingdom would have suffered a terrifying natural disaster. But Princess Andromeda was saved by the brave hero Perseus, who, on his winged horse Pegasus, was able to defeat the terrible Kraken. Subsequently, the names of the heroes of favorite myths Perseus and Andromeda were named bright stars in the night sky, only later it turned out that Andromeda is not just a star, but a whole galaxy, and the Perseus cluster is even something bigger - a real cluster of galaxies.

Mythological Perseus and Andromeda, who gave their names to galaxies.

Over the course of a century, many astronomers noticed and observed Andromeda, and in 964 the Persian astronomer Abdurahman al-Sufi wrote about her, affectionately calling her “Little Cloud.” In 1780, William Herschel observed it through his telescope, believing that it was not so far from us.

The first photograph of the Andromeda system was taken in 1887 by the English astronomer from Wales Issac Roberts, who, however, mistakenly considered it part of our Milky Way galaxy. The understanding that the Andromeda system is a whole separate galaxy with many of its own stars came only at the beginning of the last century. American astronomer Heber Curtis, observing Andromeda in 1917, noticed that the stars of the Andromeda nebula were ten magnitudes fainter than those in other places. According to him, they were 500,000 light years away from us. He was the first to put forward the hypothesis of spiral nebulae or, as it was also called, the “hypothesis of island universes.” According to this hypothesis, spiral nebulae are separate and full-fledged galaxies.

Experimental confirmation of Curtis's ideas took place in 1923, thanks to another great American astronomer, Edwin Hubble, who built his famous 100-inch telescope. It was Edwin Hubble who was the first to calculate the exact distance to the Andromeda system - 2.5 million light years, and it was he who finally proved that our Universe consists of many galaxies, and not just the Milky Way (as previously believed) and Andromeda is only one of countless numbers galaxies around.

Photo of the Andromeda Galaxy

A few photos of our “neighbor” in the Universe

Andromeda Galaxy and Milky Way

The size of the Andromeda galaxy far exceeds the size of our native galaxy, and we can absolutely say that Andromeda is the largest galaxy in our part of the Universe. Andromeda has about one trillion stars, while our Milky Way is much poorer with its three hundred billion stars. Andromeda is also many times larger in extent than our galaxy - it stretches over 260 thousand light years (for comparison, our Milky Way here is only one hundred thousand light years long). Andromeda is ahead of our galaxy in terms of quantity; scientists have already counted more than 30 of the latter.

And the most interesting thing is that the Andromeda galaxy is approaching us, and at a not so low speed of 100-140 km per second. This means that in four and a half billion years there will be a collision between the Milky Way and the Andromeda galaxy, after which both galaxies will merge into one even larger galaxy. But we shouldn’t worry about this, since the Earth, and ours in general, are unlikely to suffer from this collision - the chances of two stars colliding during a galaxy merger are negligible, due to the huge size of these same galaxies. In the worst case scenario, our solar system will be thrown into intergalactic space by powerful gravitational waves. But she herself will not suffer.

Here the picture clearly shows how the collision of our galaxies will occur.

Planets of the Andromeda Galaxy and the presence of intelligent life

Here we leave solid ground scientific facts and we step onto the slippery ice of speculation and hypotheses. Due to the scale of the Andromeda system, the presence of many stars on it and more more planets, it is quite possible, at least according to the logic of probability theory, that among this set of planets there are planets quite suitable for life. And if so, then life appeared there, and not only animal, but also quite intelligent. Well, for now we can only guess and fantasize a little about what the inhabitants of the Andromeda galaxy look like.

Again in computer game Mass Effect Andromeda The inhabitants of Andromeda are of the humanoid type, that is, they are similar in appearance to us - they have two arms, two legs, one head, although, of course, intelligent life there can be in a completely different form.

How to Find the Andromeda Galaxy in the Sky

If you are wondering how to see the Andromeda Galaxy in the night sky, and with the naked eye, then it is not so difficult to do. The best time to view Andromeda is from October to November. To begin with, you should find the constellation Pegasus in the night sky, it is located in the south. Halfway from the horizon to the zenith, you should notice a large square of four stars of almost equal brightness - this is the brightest and most visible part of the constellation Pegasus.

On the left, a chain of stars curved upward adjoins the square, forming together with the square a figure vaguely reminiscent of a ladle with a handle. The pen stars, including the top left star of the square, belong to the Andromeda Galaxy.

Andromeda Galaxy, video

And finally, here is an interesting educational film from the Discovery Channel about the future collision of the Andromeda galaxy with our galaxy.

Astronomical observations are very exciting activity, which can “hook” any person. The night sky reveals a wide variety of objects that can be observed through a telescope, binoculars, or even with the naked eye. However, it often happens that it is difficult for a novice amateur to begin making observations. It’s good if there is a Moon and bright planets that stand out against the background of stars in the sky. And if not? Unfamiliar star patterns are usually simply confusing, and a beginner quickly loses interest in the sky.

Of course, if you want to gain experience in astronomical observations, you need to start by studying the constellations. Knowledge of the basic star patterns will allow you to navigate well in the sky and in the future find a wide variety of celestial objects- from comets to distant galaxies. But you often hear that learning constellations is boring. In this case, you can combine the useful with the pleasant and, together with the constellations, find other celestial objects: planets, nebulae, star clusters.

A modern city dweller has no idea how many interesting things can be seen in the sky with the naked eye, without the help of any optics! We are not used to looking at the night sky due to strong light pollution. However, even in urban conditions (unless you are a resident of a metropolis) it is possible to see fairly faint celestial objects. To do this, first of all, you should find a place protected from street lights. A park, city outskirts, or even a corner of a house will do. By finding cover and giving your eyes time to adjust to the darkness, you'll be surprised at how many faint stars appear in your field of vision.

In the mid-autumn evenings, the constellations dominate in the south Pegasus And Andromeda. Start your acquaintance with the sky with these constellations! They are easy to find, and most importantly, they will become a reference point for finding other autumn constellations and the famous M31 galaxy, known as Andromeda's nebula.

To find the constellation Pegasus, look south after 20:00. Halfway from the horizon to the zenith, a large square of four stars of almost equal brightness will catch your eye. This drawing (without the upper left corner) is the most noticeable part of the Pegasus constellation. On the left, a chain of stars curved upward adjoins the square, forming together with the square a figure vaguely reminiscent of a ladle with a handle. The stars of the pen, including the upper left star of the square, belong to the constellation Andromeda.

The constellations Pegasus and Andromeda are visible high in the southern sky on October evenings. Drawing: Stellarium

Andromeda and Pegasus are the main and most expressive constellations of mid-autumn. Of course, in the early evening, they are still visible in their place, and closer to night, much brighter winter constellations rise in the east. But in the evenings in October, Pegasus and Andromeda reign in the sky.

In the constellation Andromeda there is Andromeda's nebula, a giant spiral galaxy located 2 million light years from Earth. Many will be surprised, but the Andromeda Nebula can be seen with the naked eye. This is not easy to do in a city, but under good atmospheric conditions the author of these lines was able to observe the galaxy even in a city with a population of half a million people.

How to find the Andromeda Nebula? Start from the left top edge Pegasus Square. Follow the handle of the “bucket” to the star Mirakh (β Andromeda). Above it you will see two dim stars, denoted by the Greek letters mu (μ) and nu (ν). The Andromeda nebula is located just above and to the right of ν Andromeda.

The Andromeda nebula is located above the star Mirach, the middle one in the arm of Andromeda. In the figure, the nebula is shown as an elongated nebula. Drawing: Stellarium

Look closely at this part of the sky. If you don't notice a faint hazy glow, try looking at the area with your peripheral vision. Shake your head slightly from side to side. If you see the star Nu Andromeda clearly enough, most likely your peripheral vision will “catch” the movement of a faint speck.

Pegasus Square, Andromeda constellation and Andromeda Nebula. The galaxy is located above the star Mirakh and the stars μ and ν Andromeda. Drawing: Stellarium

Remember that the light coming from the galaxy traveled two million light years. How far is this distance? Do the math for yourself: the speed of light is 300 thousand km/s, and the time it took to fly to Earth is 2 million years... Just think, at the time when this light started to reach Earth, there was no man on our planet yet!

The Andromeda nebula is the most distant object in space visible to the naked eye. Try and see it in mid-October, while the moonlight does not interfere with observations!

The Andromeda nebula is the closest large galaxy to us. Even in amateur photos she looks amazing. Photo: Julian Wessel

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 makes it possible to observe it with the naked eye in the sky as a slightly oblong speck. This is achieved by the fact that Andromeda contains about a trillion stars (thereby exceeding its size by at least 2.5 times and being the largest galaxy Local group). However, despite the huge number of 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 Alferats (the brightest star of the Andromeda constellation) 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 towards us at a speed of 300 km/s) and a supernova explosion recorded in 1917 (which gave the first approximate value of the distance to it - 500 thousand St. years). However, only Edwin Hubble managed to put a final point in the dispute between scientists.

Which can be seen in the sky with the naked eye and is the only spiral galaxy (except for our own) that is quite reliably visible in the suburban sky. Best time For observations of the Andromeda Nebula - dark, moonless autumn evenings. At this time, the galaxy is high in the sky, where the transparency of the sky is higher than at the horizon, and city light is not too bothersome.

Among all the deep space objects, the Andromeda Nebula is perhaps the brightest and largest object in the autumn sky. How to find this galaxy in the sky in autumn?

There are two classic methods.

Method number 1: starting from the Pegasus Square

If the main star pattern in the summer sky is , then in the fall it is replaced by another asterism - Great Square of Pegasus. (They are often called without the “big” prefix.) The Pegasus Square after sunset is in the southeast, to the left of the Summer Triangle, and towards midnight it is in the southern side of the sky. Find this quadrilateral. (Hint: the stars that make it up are about the same brightness as the stars of the Big Dipper, which is visible in the north at this time.)

Summer Triangle and Pegasus Square in the autumn sky. Drawing: Stellarium

Adjacent to the square on the left a chain of three stars of approximately comparable brilliance. The chain bends upward, making the Pegasus square look like a huge coffee pot. The stars in this chain belong to the Andromeda constellation.

Now pay attention to the middle star in the chain, or rather, to its surroundings: above it you will see two more stars - much dimmer. This is by the way good test - If you can confidently see these stars, then most likely you will be able to see the Andromeda Nebula . If you see two stars with difficulty, then the quality of the sky is not good, and you will have to use binoculars or a telescope to find the Andromeda Galaxy. (There's nothing wrong with that, it's just that not everyone has them!)

So, there is one last step left. The Andromeda nebula is located just above and to the right of the second star, called Andromeda nude.

Pegasus Square, Andromeda constellation and the Andromeda Nebula (circled). Drawing: Stellarium

Method number 2: starting from the constellation Cassiopeia

The constellation Cassiopeia is familiar to many thanks to its characteristic pattern - it looks like the letter M or the Latin letter W. This small constellation is visible in our sky all year round. In autumn, in the evenings, Cassiopeia can be observed in the eastern part of the sky at an altitude of about 60° above the horizon, and at midnight - at the zenith.

The constellation Andromeda is located under the constellation Cassiopeia. If in the figure W we take the third and fourth stars (counting from left to right), mentally connect them with a line and extend this line three times the distance down (slightly at an angle, as in the figure), then this line will point to the Andromeda Nebula.

The Andromeda Nebula can be found by starting from the stars of Cassiopeia. Drawing: Stellarium

Both search options are equally simple. Perhaps the first method is somewhat more reliable, since it gives the position of the nebula directly next to the star. But you can easily combine two methods - say, find the constellation Andromeda from the constellation Cassiopeia, and the Andromeda Nebula using two stars.

Now a few words about What does a galaxy look like to the naked eye?. In the dark sky it will appear as a dim elongated speck the size of half the visible disk of the Moon. You won't be able to discern any details. If the sky transparency is mediocre, the galaxy may not be visible to direct vision or may be very poorly visible. Then use peripheral vision, that is, look slightly away from the place where the Andromeda Nebula is located, and at the same time try to catch its faint glow.

It goes without saying that it is extremely difficult to see the Andromeda Galaxy in the city. Success depends heavily on the quality of the atmosphere and the choice of location. Try to find an area that is protected from street lighting as much as possible. Never watch under the moon! Before observing, give your eyes 10 minutes to adjust to the darkness. During this time, remain in complete darkness. The rest depends on your patience, experience and atmospheric conditions.

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 Andromeda constellation 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 century, with the appearance powerful telescopes. There are also variables, star clusters, planetary nebulae, dwarf galaxies and other interesting objects in Andromeda.

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. The Hubble telescope was of particular importance 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

IN currently 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 tells about the beautiful princess Andromeda, who was given over by King Kepheus to be devoured by a sea monster. She was freed by Perseus, and after her death the gods placed her in the starry sky.