If the baby has grown to the age of "why" and bombards you with questions about why the stars shine, how far to the sun and what a comet is, it's time to introduce him to the basics of astronomy, help him understand the structure of the world, support research interest.
"If there was only one place on Earth from where one could see the stars, then people would flock there in droves to contemplate the wonders of the sky and admire them." (Seneca, 1st century AD) It is hard to disagree that in this sense, little has changed on earth for thousands of years.
The bottomlessness and immensity of the starry sky still inexplicably attracts the views of people,
fascinates, hypnotizes, fills the soul with quiet and gentle joy, a feeling of unity with the entire universe. And if even the adult imagination sometimes draws amazing pictures, then what can we say about our children, dreamers and inventors who live in fairy-tale worlds, fly in their sleep and dream of space travel and encounters with alien intelligence...
Where to begin?
Acquaintance with astronomy should not begin with the "big bang theory". It is sometimes difficult even for an adult to realize the infinity of the Universe, and even more so for a baby, for whom even his own home is still akin to the Universe. It is not necessary to buy a telescope right away. This is a unit for "advanced" young astronomers. In addition, many interesting observations can be made with the help of binoculars. And it’s better to start with buying a good book on astronomy for kids, with a visit to the children’s program at the planetarium, the space museum, and, of course, with interesting and intelligible stories from mom and dad about planets and stars.
Tell your child that our Earth is a huge ball on which there was a place for rivers, mountains, forests, deserts, and, of course, all of us, its inhabitants. Our Earth and everything that surrounds it is called the Universe or space. Space is very large, and no matter how much we fly in a rocket, we will never be able to get to its edge. In addition to our Earth, there are other planets, as well as stars. Stars are huge luminous fireballs. The sun is also a star. It is located close to the Earth, and therefore we see its light and feel heat. There are stars many times larger and hotter than the Sun, but they shine so far from the Earth that they seem to us just small dots in the night sky. Often kids ask why the stars are not visible during the day. Compare with your child the light of a flashlight during the day and in the evening in the dark. In the daytime, in bright light, the beam of the flashlight is almost invisible, but it shines brightly in the evening. The light of the stars is like the light of a lantern: during the day it is outshone by the sun. Therefore, the stars can only be seen at night.
In addition to our Earth, 8 more planets circle the Sun, many small asteroids and comets. All these celestial bodies form the solar system, the center of which is the sun. Each planet has its own path, which is called an orbit. To remember the names and order of the planets, the baby will help "Astronomical rhyme" by A. Usachev:
An astrologer lived on the moon, He counted the planets. Mercury - one, Venus - two, three - Earth, four - Mars. Five - Jupiter, six - Saturn, Seven - Uranus, eighth - Neptune, Nine - farthest - Pluto. Who does not see - get out.
Tell your child that all the planets in the solar system vary greatly in size. If you imagine that the largest of them, Jupiter, is the size of a large watermelon, then the smallest planet, Pluto, will look like a pea. All planets in the solar system, except for Mercury and Venus, have satellites. Our Earth also has it...
mysterious moon
Even a one and a half year old toddler is already enthusiastically looking at the moon in the sky. And for a grown-up kid, this satellite of the Earth can become an interesting object of study. After all, the Moon is so different and is constantly changing from a barely noticeable "sickle" to a round bright beauty. Tell the kid, and even better, demonstrate with the help of a globe, a small ball (this will be the Moon) and a flashlight (this will be the Sun), how the Moon revolves around the Earth and how it is illuminated by the Sun.
In order to better understand and remember the phases of the moon, start an observation diary with your baby, where every day you will sketch the moon as it is visible in the sky. If on some days clouds interfere with your observations, it does not matter. Still, such a diary will be an excellent visual aid. And to determine whether the moon is waxing or waning in front of you is very simple. If her sickle looks like the letter "C" - she is old, if the letter "R" without a stick - growing.
Of course, the baby will be interested to know what is on the moon. Tell him that the surface of the moon is covered with craters caused by asteroid impacts. If you look at the Moon with binoculars (it is better to install it on a photo tripod), then you can notice the unevenness of its relief and even craters. The moon has no atmosphere, so it is not protected from asteroids. But the Earth is protected. If a stone shard enters its atmosphere, it immediately burns up. Although sometimes asteroids are so fast that they still have time to fly to the surface of the Earth. Such asteroids are called meteorites.
Star riddles
While relaxing with your grandmother in the village or in the country, devote a few evenings to stargazing. There is nothing to worry about if the child breaks the usual routine a little and goes to bed later. But how many unforgettable minutes he will spend with mom or dad under a huge starry sky peering into the shimmering mysterious dots. August is the best month for such observations. The evenings are quite dark, the air is transparent and it seems that you can reach the sky with your hands. It's easy to see in August interesting phenomenon, which is called a "shooting star". Of course, in fact, this is not a star at all, but a burning meteor. But still very beautiful. Our distant ancestors looked at the sky in the same way, guessing various animals, objects, people, mythological heroes in the clusters of stars. Many constellations bear their names from time immemorial. Teach your child to find a particular constellation in the sky. Such an activity awakens imagination in the best possible way and develops abstract thinking. If you yourself are not very good at navigating the constellations, it does not matter. Almost all children's books on astronomy have a map of the starry sky and descriptions of the constellations. In total, 88 constellations have been identified on the celestial sphere, 12 of which are zodiacal. The stars in the constellations are designated by letters of the Latin alphabet, and the brightest ones have their own names (for example, the star Altair in the constellation Eagle). To make it easier for a child to see this or that constellation in the sky, it makes sense to first carefully examine it in the picture, and then draw or lay it out of cardboard stars. You can make constellations on the ceiling using special luminous star stickers. Once having found a constellation in the sky, the child will never forget it.
At different peoples the same constellation could be called differently. It all depended on what their fantasy suggested to people. So, the well-known Ursa Major was depicted both as a ladle and as a horse on a leash. Amazing legends are associated with many constellations. It would be great if mom or dad would read some of them in advance, and then retell them to the baby, peering into the luminous dots with him and trying to see the legendary creatures. The ancient Greeks, for example, had such a legend about the constellations Ursa Major and Ursa Minor. The almighty god Zeus fell in love with the beautiful nymph Callisto. The wife of Zeus Hera, having learned about this, was terribly angry and turned Callisto and her friend into a she-bear. The son of Callisto Araks met two bears during a hunt and wanted to kill them. But Zeus prevented this by throwing Callisto and her friend into the sky and turning them into bright constellations. And, throwing, Zeus held the bears by the tails. Here are the tails and have become long. And here is another beautiful legend about several constellations at once. A long time ago, Cepheus lived in Ethiopia. His wife was the beautiful Cassiopeia. They had a daughter, the beautiful princess Andromeda. She grew up and became the most beautiful girl in Ethiopia. Cassiopeia was so proud of her daughter's beauty that she began to compare her with goddesses. The gods were angry and sent a terrible misfortune to Ethiopia. Every day a monstrous whale swam out of the sea, and the most beautiful girl was given to him to be eaten. The turn of the beautiful Andromeda has come. No matter how Cepheus begged the gods to spare his daughter, the gods remained adamant. Andromeda was chained to a rock by the sea. But at this time, the hero Perseus flew past in winged sandals. He had just accomplished the feat of killing the dreaded Medusa Gorgon. Instead of hair, snakes moved on her head, and one look from her turned all living things into stone. Perseus saw a poor girl and a terrible monster, pulled out the severed head of Medusa from the bag and showed it to the whale. The whale was petrified, and Perseus freed Andromeda. Delighted, Cepheus gave Andromeda as his wife to Perseus. And the gods liked this story so much that they turned all its heroes into bright stars and placed them in the sky. Since then, you can find there: Cassiopeia, and Cepheus, and Perseus, and Andromeda. And the whale became an island off the coast of Ethiopia.
It is not difficult to find the Milky Way in the sky. It is clearly visible to the naked eye. Tell your child that the Milky Way (namely, this is the name of our galaxy) is a large cluster of stars that looks like a luminous strip of white dots in the sky and resembles a milk path. The ancient Romans attributed the origin Milky Way sky goddess Juno. When she was breastfeeding Hercules, a few drops fell and, turning into stars, formed the Milky Way in the sky ...
Choosing a telescope
If a child is seriously interested in astronomy, it makes sense to purchase a telescope for him. True, a good telescope is not cheap. But even inexpensive models of children's telescopes will allow a young astronomer to observe many celestial objects and make his first astronomical discoveries. Mom and dad should remember that even the simplest telescope is a rather complicated thing for a preschooler. Therefore, firstly, the child can not do without your active help. And, secondly, the simpler the telescope, the easier it will be for the baby to manage it. If in the future the child becomes seriously interested in astronomy, it will be possible to purchase a more powerful telescope.
So, what is a telescope and what to look for when choosing one? The principle of operation of the telescope is not based on the magnification of the object, as many people think. It is more correct to say that the telescope does not enlarge, but brings the object closer. The main task of the telescope is to create an image of a distant object close to the observer and allow details to be distinguished; not accessible to the naked eye; The second task is to collect as much light as possible from a distant object and transmit it to our eye. So, the larger the lens, the more light the telescope collects and the better the detail of the objects in question will be.
All telescopes are divided into three optical classes. Refractors(refracting telescopes) a large objective lens is used as a light-collecting element. IN reflex(reflecting) telescopes, concave mirrors play the role of an objective. The most common and easiest to manufacture reflector is made according to optical scheme Newton (named after Isaac Newton, who first put it into practice). Often these telescopes are called "Newton". Mirror lens Telescopes use both lenses and mirrors at the same time. Due to this, they allow you to achieve excellent image quality with high resolution. Most children's telescopes that you will find in stores are refractors.
An important parameter to pay attention to is lens diameter(aperture). It determines the light gathering power of the telescope and the range of possible magnifications. It is measured in millimeters, centimeters or inches (for example, 4.5 inches is 114 mm). The larger the diameter of the lens, the more "weak" stars can be seen through a telescope. The second important feature is focal length. The aperture ratio of the telescope depends on it (as in amateur astronomy they call the ratio of the diameter of the lens to its focal length). Pay attention also to eyepiece. If the main optic (objective lens, mirror or system of lenses and mirrors) serves to form an image, then the purpose of the eyepiece is to magnify this image. Eyepieces come in different diameters and focal lengths. Changing the eyepiece will also change the magnification of the telescope. To calculate the magnification, you need to divide the focal length of the telescope objective (say, 900 mm) by the focal length of the eyepiece (for example, 20 mm). We get a magnification of 45 times. This is quite enough for a novice young astronomer to consider the Moon, star clusters and a lot of other interesting things. The telescope kit may include a Barlow lens. It is installed in front of the eyepiece, which increases the magnification of the telescope. In simple telescopes, the double barlow lens. It allows you to double the magnification of the telescope. In our case, the increase will be 90 times.
The telescopes come with many useful accessories. They can be included with the telescope or ordered separately. For example, most telescopes are equipped with viewfinders. This is a small telescope with a low magnification and a large field of view, which makes it easy to find the desired objects of observation. The viewfinder and telescope are directed parallel to each other. First, the object is determined in the viewfinder, and only then in the field of the main telescope. Almost all refractors are equipped with diagonal mirror or prism. This device facilitates observations if the object is directly above the astronomer's head. If, in addition to celestial objects, you are going to observe terrestrial objects, you cannot do without rectifying prism. The fact is that all telescopes receive an image turned upside down and mirrored. When observing celestial bodies, this does not really matter. But to see earthly objects is still better in the correct position.
Any telescope has a mount - a mechanical device for attaching the telescope to a tripod and aiming at an object. It can be azimuth or equatorial. The azimuth mount allows you to move the telescope in the horizontal direction (left-right) and vertical (up-down). This mount is suitable for observing both terrestrial and celestial objects and is most often installed in telescopes for novice astronomers. Another type of mount, equatorial, is arranged differently. During long-term astronomical observations, due to the rotation of the earth, objects shift. Thanks to a special design, the equatorial mount allows the telescope to follow the curved path of the star across the sky. Sometimes such a telescope is equipped with a special motor that controls the movement automatically. A telescope on an equatorial mount is more suitable for long-term astronomical observations and photography. And finally, this whole device is mounted on tripod. Most often it is metal, less often - wooden. It is better if the legs of the tripod are not fixed, but retractable.
How to work
Seeing something through a telescope is not such an easy task for a beginner as it might seem at first glance. You need to know what to look for. This time. You need to know where to look. This is two. And, of course, know how to search. It's three. Let's start from the end and try to figure out the basic rules for handling a telescope. Don't worry about the fact that you yourself are not very good at astronomy (or even not at all). Finding the right literature is not a problem. But how interesting it will be for both you and the child to discover this difficult, but such an exciting science together.
So, before you start searching for any object in the sky, you need to set up a viewfinder with a telescope. This procedure requires some skill. Do it better during the day. Select a fixed, easily recognizable ground object at a distance of 500 meters to one kilometer. Point the telescope at it so that the object is in the center of the eyepiece. Fix the telescope so that it is stationary. Now look through the viewfinder. If the selected subject is not visible, loosen the viewfinder adjustment bolt and rotate the viewfinder itself until the subject appears in the field of view. Then, use the adjustment screws (viewfinder fine adjustment screws) to ensure that the object is exactly in the center of the eyepiece. Now look through the telescope again. If the object is still in the center - everything is in order. The telescope is ready to go. If not, repeat the setting.
As you know, it is better to look through a telescope in a dark tower somewhere high in the mountains. Of course, we are unlikely to go to the mountains. But, undoubtedly, it is better to watch the stars outside the city (for example, in the country) than from the window of a city apartment. There is too much extra light and heat waves in the city, which will degrade the image. The farther away from urban illumination you make observations, the more celestial objects you will be able to see. It is clear that the sky should be as clear as possible.
First find the subject in the viewfinder. Then adjust the focus of the telescope - turn the focus screw until the image is clear. If you have multiple eyepieces, start with the lowest magnification. Due to the very fine tuning of the telescope, you need to look into it carefully, without making sudden movements and with bated breath. Otherwise, the setting can easily go astray. Teach your child right away. By the way, such observations will train endurance, and for overly active smart people they will become a kind of psychotherapeutic procedure. It is difficult to find a better soothing remedy than watching the endless starry sky.
Depending on the model of the telescope, several hundred different celestial objects can be viewed through it. These are planets, stars, galaxies, asteroids, comets.
asteroids(minor planets) are large pieces of rock, sometimes containing metal. Most asteroids orbit the Sun between Mars and Jupiter.
Comets- These are celestial bodies that have a core and a luminous tail. So that the baby can imagine this "tailed wanderer" at least a little, tell her that she looks like a huge snowball mixed with space dust. In a telescope, comets appear as hazy spots, sometimes with a light tail. The tail is always turned away from the Sun.
Moon. Even with the simplest telescope, you can clearly see craters, crevices, mountain ranges and dark seas. It is best to observe the moon not during the full moon, but during one of its phases. At this time, you can see much more details, especially at the border of light and shadow.
planets. Any telescope can see all the planets solar system, except for the most distant - Pluto (it is visible only in powerful telescopes). Mercury and Venus, as well as the Moon, have phases when they are visible through a telescope. On Jupiter, you can see dark and light bands (which are belts of clouds) and a giant whirlwind of the Great Red Spot. Due to the rapid rotation of the planet, its appearance is constantly changing. Jupiter's four helium moons are clearly visible. On the mysterious red planet Mars, with a good telescope, you can see the white ice caps at the poles. The famous ring of Saturn, which children love to look at in pictures, is also perfectly visible through a telescope. This is an amazing picture. The largest moon of Saturn, Titan, is usually clearly visible. And in more powerful telescopes, you can see the gap in the rings (Cassini gap) and the shadow that the rings cast on the planet. Uranus and Neptune will be visible as small dots, and in more powerful telescopes as disks.
Between the orbits of Mars and Jupiter, many asteroids can be observed. Sometimes comets come across.
star clusters. Throughout our galaxy, there are many star clusters, which are divided into scattered (a significant cluster of stars in some part of the sky) and globular (dense group of stars, shaped like a ball). For example, the Pleiades constellation (seven small stars pressed against each other), clearly visible to the naked eye, turns into a sparkling field of hundreds of stars in the eyepiece of even the simplest telescope.
Nebulae. Scattered throughout our galaxy are clusters of gas. This is what nebulae are. Usually they are illuminated by neighboring stars and are a very beautiful sight.
galaxies. These are huge clusters of billions of stars, separate "islands" of the Universe. The brightest galaxy in the night sky is the Andromeda Galaxy. Without a telescope, it looks like a faint blur. A large elliptical luminous field can be seen through a telescope. And in a more powerful telescope, the structure of the galaxy is visible.
Sun. It is strictly forbidden to look at the Sun through a telescope, unless it is equipped with special solar filters. Explain this to your child first. This will damage the telescope. But this is half the trouble. There is one sad aphorism that you can look at the Sun through a telescope only twice in your life: once with your right eye, the second time with your left. Such experiments can indeed lead to loss of vision. And it is better not to leave the telescope assembled in the daytime, so as not to tempt the little astronomer.
In addition to astronomical observations, most telescopes allow you to observe terrestrial objects, which can also be very interesting. But, much more important, not so much the observations themselves, but the joint passion of the baby and parents, common interests that make the friendship between the child and the adult stronger, fuller and more interesting.
Clear skies and amazing astronomical discoveries!
In 2013, an amazing event took place in astronomy. Scientists saw the light of a star that exploded ... 12,000,000,000 years ago, in the Dark Ages of the Universe - this is how astronomy calls the time period of one billion years that has elapsed after big bang.
When the star died, our Earth did not yet exist. And only now the earthlings saw its light - for billions of years wandering through the Universe, farewell.
Why do the stars glow?
Stars shine because of their nature. Each star is a massive ball of gas held together by gravity and internal pressure. Intense fusion reactions are going on inside the ball, the temperature is millions of kelvins.
Such a structure provides a monstrous radiance cosmic body, capable of overcoming not only trillions of kilometers (to the nearest star from the Sun, Proxima Centauri - 39 trillion kilometers), but also billions of years.
The brightest stars observed from Earth are Sirius, Canopus, Toliman, Arcturus, Vega, Capella, Rigel, Altair, Aldebaran, and others. 
Their apparent color directly depends on the brightness of the stars: blue stars are superior in radiation strength, followed by blue-white, white, yellow, yellow-orange and orange-red.
Why are the stars not visible during the day?
It's all to blame - the closest star to us, the Sun, in the system of which the Earth enters. Although the Sun is not the brightest and not the most big star, the distance between it and our planet is so insignificant in terms of cosmic scales that sunlight literally floods the Earth, making all other faint glow invisible.
In order to see for yourself what was said above, you can conduct a simple experiment. Make holes in the cardboard box, and mark the light source (desk lamp or flashlight) inside. In a dark room, holes will glow like little stars. And now "turn on the sun" - the overhead room light - the "cardboard stars" will disappear. 
This is a simplified mechanism that fully explains the fact that we cannot see starlight during the day.
Are the stars visible during the day from the bottom of mines, deep wells?
During the day, the stars, although not visible, are still in the sky - they, unlike the planets, are static and are always at the same point.
There is a legend that daytime stars can be seen from the bottom of deep wells, mines, and even high and wide enough (to fit a person) chimneys. It was considered true for a record number of years - from Aristotle, an ancient Greek philosopher who lived in the 4th century BC. e., to John Herschel, an English astronomer and physicist of the XIX century.
It would seem: what is easier - get down into the well and check! But for some reason, the legend lived on, although it turned out to be absolutely false. Stars from the depths of the mine are not visible. Simply because there are no objective conditions for this.
Perhaps the reason for the appearance of such a strange and tenacious statement is the experience proposed by Leonardo da Vinci. To see the actual image of the stars as seen from Earth, he would make small holes (pupil-sized or smaller) in a sheet of paper and place them over his eyes. What did he see? Tiny glowing dots - no jitter or "rays".
It turns out that the radiance of stars is a merit of the structure of our eye, in which the lens bends light, having a fibrous structure. If we look at the stars through a small hole, we pass such a thin beam of light into the lens that it passes through the center, almost without bending. And the stars appear in their true form - as tiny dots.
As can be remembered from school course science, stars are objects that have the ability to emit their own light. Unlike them, other celestial bodies such as planets, satellites, asteroids and comets are visible in the sky due to reflected light, they do not have their own glow. The only exceptions are meteorites that have fallen into the Earth's atmosphere, falling due to the force of its gravity. They burn out partially or completely in the process of falling due to friction against air particles, and glow due to this.
But why do the stars glow? This is an interesting question, to which astronomers are ready to give an exhaustive answer.
The history of the study of stars and their glow
For a long period of time, astronomers could not agree on the nature of starlight. This question has given rise to numerous controversies over the centuries. These disputes were not only scientific in nature - at the dawn of civilization, people built numerous myths, legends and religious conjectures that explain the presence of stars in the sky and their glow. In the same way, legends and everyday explanations of other astronomical phenomena observed in the sky were created - comets, eclipses, the movement of the stars.
Interesting fact: some civilizations believed that the stars in the sky were the souls of the dead, others believed that they were nail heads that nailed the sky. The sun, on the other hand, has always been considered separately, it has not been ranked among the stars for thousands of years, it was too different in its appearance observed from the Earth's surface.
With the development of astronomy, the fallacy of such conclusions was clarified, and the stars began to be explored anew - like the Sun. Subsequently, it was possible to clarify that the Sun is also a star. Modern scientists classify the star closest to us as a red dwarf. However, the nature of the glow of the Sun and other stars gave rise to a lot of controversy until very recently.
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Theories explaining the glow of stars
In the 19th century, many scientific minds believed that a burning process was taking place on the stars - exactly the same as in any earthly stove. But this theory did not justify itself at all. It is difficult to imagine how much fuel should be on a star so that it can give heat for millions of years. Therefore, this version does not deserve consideration. Chemists believed that exothermic reactions occur on stars, which provide a powerful release of large amounts of heat.
But physicists will not agree with such an explanation, for the same reason as with the combustion process. The reserves of substances that react must be huge in order to maintain the glow of the stars and their ability to give heat.
After the discoveries of Mendeleev, the situation changed again, as the era of the study of radiation and radioactive elements began. At that time, the heat and light generated by the stars and the Sun were unconditionally attributed to the reactions of radioactive decay, this version became generally accepted for decades. Subsequently, it was revised many times.
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Modern opinion of scientists about the causes of stellar glow
Modern scientists are fully convinced that the nuclear fusion that occurs in the cores of stars is capable of providing the release of the amount of energy that each star emits every second. This process is capable of providing luminescence and heat release in huge volumes for billions of years.
Therefore, the theory is generally accepted. Energy from the depths passes into the gas shells of the star, from where it radiates outward. In the circles of astronomers, there is an opinion that it takes tens, hundreds of thousands of years to move energy from the depths of a star to its surface - this is by no means an instantaneous process. Therefore, a star can still shine for a long time even after the synthesis in its depths stops due to a lack of initial chemical elements.
Light from any of the stars does not reach the surface of the Earth instantly either. Even from the Sun, the closest star to our planet, it takes about 8 minutes. The next closest star to our planet is Proxima Centauri. It takes more than four years for light to reach Earth from it.
Each star is a huge luminous ball of gas, like our Sun. A star shines because it releases a huge amount of energy. This energy is formed as a result of the so-called thermonuclear reactions. Each star is a huge luminous ball of gas, like our Sun. A star shines because it releases a huge amount of energy. This energy is formed as a result of the so-called thermonuclear reactions.Each star contains many chemical elements. For example, the presence of at least 60 elements has been detected on the Sun. Among them are hydrogen, helium, iron, calcium, magnesium and others. > What are stars? Each star is a huge ball of hot gases. As a rule, hydrogen makes up about 90%, helium a little less than 10%, and the rest is impurities of other gases. In the center of the star, there must be a temperature of the order of 6,000,000 ° C in order for a thermonuclear reaction to take place. During a thermonuclear reaction, hydrogen is converted into helium, and a huge amount of energy is released. This energy, breaking out, does not allow the star to shrink due to its own forces of attraction and is radiated into space in the form of light. The smallest stars are about 10 times smaller than the Sun. The largest known stars are 150 times larger than the Sun. The closest star to us is Proxima from the Alpha Centauri system. Its distance is 4.22 light years. To fly to it at the speed that is now achievable, it will take several thousand years. To do this, you need to come up with spaceship that would ensure the life of several generations of people. There are no technologies that would provide this yet. On the other hand, it is possible to develop a spacecraft that could fly as close to the speed of light as possible. But such a ship does not yet exist. People have long dreamed of flying to the stars. Scientists have been working on this problem for many years, but it will take a long time before it is finally solved. The star is celestial body, which is seen from Earth as a luminous dot in the night sky. In general, stars are huge balls of hot gases. In their central part, the temperature reaches 6,000,000°C. At this temperature, a thermonuclear reaction takes place, converting hydrogen into helium. This releases an enormous amount of energy. This energy from the center of the star breaks through to the surface and radiates into space as light. Interestingly, stars are often called the main bodies of the Universe, because they contain the bulk of the luminous matter in nature. If you look at the starry sky through a telescope, you will notice that in addition to stars there are various kinds and forms of nebulae that can become birthplaces for new stars. At some point in development, any gas and dust cloud of a nebula can begin to condense. It is compressed into a ball and heated to a high temperature. At the moment when the temperature reaches about 6,000,000 ° C, a thermonuclear reaction begins. During the reaction, hydrogen is converted into helium and a huge amount of energy is released, which breaks through to the surface and radiates into space in the form of light. This is what our Sun is like right now. Among the stars are white and red dwarfs, new and supernovae, neutron stars. Scientists call them one way or another depending on their mass, composition, characteristics of the light they emit. In addition, astronomers divide stars into classes, which are denoted by letters: O, B, A, F, G, K, M. To remember this sequence, they came up with a special formula, where the first letter of each word (in English version) the name of the class of stars: One Shaved Englishman Chewed Dates Like Carrots. Stars of different classes differ in color, brightness and mass. A large star shines for about 30 billion years. Then it turns into a supergiant and pulsates for another 70 billion years. When the fuel burns out completely and all thermonuclear reactions, which hold the outer layers of the star, the luminary turns into a neutron star. And around for a long time waves of hot gas are visible, which diverge from it in different directions. The size of neutron stars is small: rarely more than 20 kilometers in diameter. The density is 100 million times the density of the Earth. Gravity on the surface neutron star about 100 billion times more than we have on Earth. Black holes are astronomical objects with amazing properties. They attract everything to themselves with very great force: even the light of the stars cannot escape from their “trap”, so the holes themselves seem black to us. A feature of black holes is a very large mass at a fairly small size. And the harder black hole, the lower its density. So a black hole with a mass equal to the mass of the Earth would have a size of about 9 millimeters, and supermassive black holes have a density of only about 20 kg / m3 much less than the density of water. Black holes usually form from big stars where thermonuclear reactions have ceased. These stars begin to shrink until a black hole is formed. Many luminaries familiar to us are multiples, that is, they consist of several stars revolving around each other. The nearest multiple star to us is the Alpha Centauri triple system. It has three parts: Alpha A Centauri, Alpha B Centauri and Proxima. brightest multiple star system Sirius. It has two parts: Sirius A and Sirius B. Moreover, the latter has an unusually large mass in relation to its size. It was the first white dwarf discovered in the sky. Some binary stars are called eclipsing variables. These are such systems of two luminaries, in which one periodically blocks the other. When one star outshines the other, the brightness decreases; when both are visible, the brightness is maximum.
Why do we see the Sun so small? Yes, because it is very far from us. Why do stars look so tiny? Remember how small our huge Sun seems to us - just the size of a soccer ball. This is because it is very far from us. And the stars are much, much further away! 
Stars like our Sun illuminate the Universe around them, warm, the planets surrounding them, give life. Why do they only glow at night? No, no, during the day they also shine, you just can't see them. In the daytime, our sun illuminates the blue atmosphere of the planet with its rays, which is why space is hidden behind a curtain. At night, this veil opens, and we see all the splendor of the cosmos - stars, galaxies, nebulae, comets and many other wonders of our Universe.What are stars?
