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. The best time to observe the Andromeda Nebula is 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 exposure 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 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 a good test, by the way - 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 galaxy also known as M31 and NGC224. This is a spiral formation located at a distance of approximately 780 kp (2.5 million from Earth.
Andromeda is the galaxy closest to the Milky Way. It is named after the mythical princess of the same name. Observations in 2006 led to the conclusion that there are about a trillion stars here - at least twice as many as in the Milky Way, where there are about 200 - 400 billion. Scientists believe that the collision of the Milky Way and the Andromeda galaxy will happen in about 3. 75 billion years, and eventually a giant elliptical or disk galaxy will be formed. But more on that a little later. First, let's find out what a "mythical princess" looks like.
The picture shows Andromeda. The galaxy has white and blue stripes. They form rings around it and cover hot, red-hot giant stars. The dark blue-gray bands contrast sharply with these bright rings and show areas where star formation is just beginning in dense cloud cocoons. When observed in the visible part of the spectrum, Andromeda's rings look more like spiral arms. In the ultraviolet range, these formations are more like ring structures. They were previously discovered by a NASA telescope. Astronomers believe that these rings indicate the formation of a galaxy as a result of a collision with a neighboring one more than 200 million years ago.
Moons of Andromeda
Like the Milky Way, Andromeda has a number of dwarf satellites, 14 of which have already been discovered. The most famous are M32 and M110. Of course, it is unlikely that the stars of each galaxy will collide with each other, since the distances between them are very large. Scientists still have rather vague ideas about what will actually happen. But a name has already been invented for the future newborn. Mammoth - this is what scientists call the unborn giant galaxy.
Star collisions
Andromeda is a galaxy with 1 trillion stars (10 12), and the Milky Way - 1 billion (3 * 10 11). However, the chance of a collision between celestial bodies is negligible, since there is a huge distance between them. For example, the star closest to the Sun, Proxima Centauri, is 4.2 light years away (4*10 13 km), or 30 million (3*10 7) the diameter of the Sun. Imagine that our luminary is a table tennis ball. Then Proxima Centauri will look like a pea, located at a distance of 1100 km from it, and the Milky Way itself will extend 30 million km in width. Even the stars in the center of the galaxy (which is where they are most concentrated) are located at intervals of 160 billion (1.6 * 10 11) km. That's like one table tennis ball for every 3.2 km. Therefore, the chance that any two stars will collide during a galaxy merger is extremely small.
Black hole collision
The Andromeda Galaxy and Milky Way have a central Sagittarius A (3.6*10 6 solar masses) and an object within the P2 cluster of the Galactic Core. These black holes will converge near the center of the newly formed galaxy, transferring orbital energy to the stars, which will eventually move to higher trajectories. The above process can take millions of years. When the black holes come within one light year of each other, they will begin to emit gravitational waves. The orbital energy will become even more powerful until the merger is complete. Based on modeling data carried out in 2006, the Earth may first be thrown almost to the very center of the newly formed galaxy, then pass near one of the black holes and be ejected beyond the Milky Way.
Confirmation of the theory
The Andromeda Galaxy is approaching us at a speed of approximately 110 km per second. Up until 2012, there was no way to know whether a collision would occur or not. The Hubble Space Telescope helped scientists conclude that it was almost inevitable. After tracking the movements of Andromeda from 2002 to 2010, it was concluded that the collision will occur in about 4 billion years.
Similar phenomena are widespread in space. For example, Andromeda is believed to have interacted with at least one galaxy in the past. And some dwarf galaxies, such as SagDEG, continue to collide with the Milky Way, creating a single formation.
Research also suggests that M33, or the Triangulum Galaxy, the third largest and brightest member of the Local Group, will also participate in this event. Its most likely fate will be the entry into orbit of the object formed after the merger, and in the distant future - final unification. However, a collision of M33 with the Milky Way before Andromeda approaches, or our Solar System is thrown out of the Local Group, is excluded.
Fate of the Solar System
Scientists from Harvard claim that the timing of the galaxy merger will depend on the tangential speed of Andromeda. Based on the calculations, we concluded that there is a 50% chance that during the merger the Solar System will be thrown back to a distance three times greater than the current one to the center of the Milky Way. It is not known exactly how the Andromeda galaxy will behave. Planet Earth is also under threat. Scientists say there is a 12% chance that some time after the collision we will be thrown outside our former “home”. But this event will most likely not have major adverse effects on the Solar System, and celestial bodies will not be destroyed.
If we exclude planetary engineering, then by time the surface of the Earth will become very hot and there will be no liquid water left on it, and therefore no life.
Possible side effects
When two spiral galaxies merge, the hydrogen present in their disks is compressed. The intensive formation of new stars begins. For example, this can be observed in the interacting galaxy NGC 4039, otherwise known as the Antennae Galaxy. If Andromeda and the Milky Way merge, it is believed that there will be little gas left on their disks. Star formation will not be as intense, although the birth of a quasar is likely.
Merger result
Scientists tentatively call the galaxy formed during the merger Milcomeda. The simulation result shows that the resulting object will have an elliptical shape. Its center will have a lower density of stars than modern elliptical galaxies. But a disk form is also possible. Much will depend on how much gas remains within the Milky Way and Andromeda. In the near future, the remaining ones will merge into one object, and this will mark the beginning of a new evolutionary stage.
Facts about Andromeda
- Andromeda is the largest Galaxy in the Local Group. But probably not the most massive. Scientists suggest that there is more concentrated in the Milky Way and this is what makes our galaxy more massive.
- Scientists are studying Andromeda in order to understand the origin and evolution of formations similar to it, because it is the closest spiral galaxy to us.
- Andromeda looks amazing from Earth. Many even manage to photograph her.
- Andromeda has a very dense galactic core. Not only are huge stars located at its center, but there is also at least one supermassive black hole hidden at its core.
- Its spiral arms were bent as a result of gravitational interaction with two neighboring galaxies: M32 and M110.
- There are at least 450 globular star clusters orbiting inside Andromeda. Among them are some of the densest that have been discovered.
- The Andromeda Galaxy is the most distant object that can be seen with the naked eye. You'll need a good vantage point and minimal bright light.
In conclusion, I would like to advise readers to look up at the starry sky more often. It stores a lot of new and unknown things. Find some free time to observe space on the weekend. The Andromeda Galaxy in the sky is a sight to behold.
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 our Milky Way, and moreover, the closest large galaxy to us. 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 of the 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 bright stars in the night sky were named after the heroes of the favorite myths Perseus and Andromeda, only then it turned out that Andromeda is not just a star, but an entire 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 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 say for sure 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 the solid ground of scientific facts and enter the slippery ice of speculation and hypotheses. Due to the scale of the Andromeda system, the presence of many stars on it and an even larger number of planets, it is quite possible, at least according to the logic of probability theory, that among this many 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 the 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.
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. 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
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 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.
