Andromeda Galaxy. Spiral Galaxy Andromeda: scientific facts and speculation

(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 But the name common to all has stuck and is still used today, although it is quickly becoming outdated.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 been transformed into citadels of light: street lighting is so bright that it successfully hid all faint stars from city residents, not to mention nebulae or the Milky Way. In addition, smog often hangs over large cities, which well scatters the light of lanterns 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 bucket Ursa Major, 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. Together the three stars 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 to the Andromeda Nebula. Pattern: Stellarium

The distance from the arrowhead to the nebula is approximately 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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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 closest star 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 black holes come within one light years from 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 Milky Way, creating a unified education.

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 the current distance 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 is not likely to have major adverse effects on 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 exploring 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 you can see naked eye. You will need good point visibility and a minimum of 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.

Astronomical observations are a very exciting activity that 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. What 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 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 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 top left edge of the 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 Andromeda Nu clearly enough, most likely your peripheral vision will “catch” the movement of the faint speck.

Pegasus Square, Andromeda constellation and Andromeda Nebula. The galaxy is located above the star Mira 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 photographs she looks amazing. Photo: Julian Wessel

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 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 on summer sky the main star pattern 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 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.

According to ancient legends, most of the constellations known to us represent immortalized events of the distant past. Mighty Gods they placed heroes and various creatures in the sky in memory of their accomplishments, and sometimes as punishment for misdeeds. Often given in this way eternal life. The Andromeda constellation is one of these celestial designs. It is famous, however, not only for its legend: its famous neighbor is located on its territory milky way and several other interesting space objects.

Mythological plot

Andromeda in ancient Greek legends was the daughter of the king of Ethiopia Kepheus (Cepheus) and his wife Cassiopeia. There are several versions of the legend associated with the constellation. According to one of them, the beautiful Andromeda was so beautiful that the Nereid sea maidens envied her. They suffered and wasted away before our eyes. Poseidon decided to rectify the situation by sending a terrible monster to Ethiopia. Every day it came ashore and destroyed villages and killed residents. Kefei turned to the Oracle for advice and learned that in order to stop the disaster, he needed to give the monster Andromeda. The saddened parents nevertheless chained their daughter to a rock and left her until the monster arrived. However, there was no tragedy: Perseus, flying past and falling in love with Andromeda at first sight, came to the beauty’s aid. He defeated the monster with his head and married a beautiful maiden. Since then, Perseus has existed and Andromeda now shines in the heavens. The gods also immortalized Cassiopeia, Kepheus and even a sea monster in the vast expanses of space.

Location

The constellation Andromeda has a well-recognized shape: three chains of luminaries radiating from one point. This celestial pattern occupies a vast area and is one of the largest in both hemispheres. The most bright star in the constellation Andromeda, the one from which the chains begin is located on the border with the image of Pegasus. Until the 17th century, the luminary was considered to belong to both celestial patterns. This star is the northern corner of Pegasus Great Square.

Andromeda can be admired throughout the vast territory of Russia. In summer and September it is located on the eastern side of the sky, and late autumn And early winter- in its southern part.

Alpha

The brightest point of this celestial pattern is Alferaz (Andromeda's alpha). It was finally fixed as part of the described constellation in 1928. For Ptolemy, Alferats belonged to Pegasus. The name itself testifies to the history of the luminary: it means “navel of a horse” in translation from Arabic.

Alferaz is a blue-white subgiant that emits 200 times more light than the Sun. In addition, it is the main component of the dual system. Its companion shines 10 times less.

Alferaz A is one of the brightest representatives of an unusual class of mercury-manganese stars. The high concentration in the atmosphere of the metals included in the name of the type is explained by the difference in the effects of the star's gravity and its internal pressure on various chemical elements.

Alferats is also a variable star. The gloss range is from +2.02 m to +2.06 m. Changes occur with a period of 23.19 hours.

Nebula

The Andromeda constellation is known to many not because of the impressive size or beauty of the stars, but because of the M31 galaxy located on its territory. The famous neighbor of the Milky Way is one of the few such objects that can be seen with the naked eye. The Andromeda nebula is located slightly above the star Mira (beta Andromeda). To view the structure of the galaxy, you will need at least binoculars.

The Andromeda nebula is more than twice the size and contains about 1 trillion stars. Near it there are also two satellites: the galaxies M32 and NGC 205. The distance from the Sun to the three objects exceeds 2 million light years.

Supernova

The constellation Andromeda became the object of observation by many astronomers in 1885. Then it lit up with a flash. It became the first such object found outside the Milky Way. Supernova S Andromeda is located in the galaxy of the same name and is still the only such cosmic body in it. The luminary reached its maximum brightness on August 21-22, 1885 (it amounted to 5.85 m). After six months it decreased to 14 m.

Today, S Andromeda is classified as a Type Ia supernova, although its orange color and light curve do not match the accepted description of such objects.

The Andromeda constellation, photos of the objects that make it up, and an image of a neighboring galaxy appear quite often in the media. And this is not surprising: the vast space occupied by the celestial pattern can tell a lot about the laws of space and the interconnection of its individual parts. Many telescopes are aimed here in the hope of obtaining new information about remote objects.