What we know about the stars. Interesting facts about stars - celestial bodies
The Pleshakov had a good idea - to create atlas for children, according to which it is easy to define stars and constellations. Our teachers picked up this idea and created their atlas-determinant, which is even more informative and visited.
What is the constellation?
If in a clear night, raise the eye into the sky, then you can see a lot of sparkling, different lights, which are like scattering of diamonds, decorate the sky. These lights are called stars. Some of them are as if collected in clusters and during long-term viewing they can be divided into certain groups. Such groups called "constellations". Some of them can resemble the shape of a bucket or intricate outlines of animals, however, in many respects, it is only the fruit of imagination.
Many centuries of astronomers tried to explore such clusters of stars and gave them mystical properties. People tried to systematize them and find a general pattern, and constellations appeared. For a long time, the constellation was carefully studied, some were smashed into smaller, and they stopped exist, and some after clarification were simply corrected. For example, Argo constellation was divided into smaller constellations: compass, keel, sail, feed.
The history of the origin of the calls of constellations is also very interesting. To facilitate the memorization, they were given names combined by one element or literary work. For example, it was noted that in the period of heavy rains the sun rises from certain constellations, which were given the following names: Capricorn, Kit, Aquarius, Constellation of fish.
To bring all constellations to a certain classification, in 1930, at a meeting of the International Astronomical Union, a decision was made on official registration of 88 constellations. According to the adopted decision, constellations are not consisting of stars, but are areas of the starry sky.
What are the constellations?
Constellations differ in the number and brightness of stars included in its composition. Allocate the 30 most notable groups of stars. The most extended Square Constellation is considered Big Dipper. It includes 7 bright and 118 visible naked stars.
The smallest constellation, located in the southern hemisphere, is called the Southern Cross and see it is impossible to see it with a naked eye. It consists of 5 bright and 25 less noticeable stars.
A small horse is the smallest constellation of the northern hemisphere and consists of 10 weak stars, which can be seen with a naked eye.
The most beautiful and vibrant is considered the constellation of Orion. It consists of 120 stars visible to the naked eye and 7 of them are very bright.
All constellations are conditionally divided into located in the southern or northern hemisphere. Those who live in the southern hemisphere of the Earth are not visible to the clusters of stars located in the North and on the contrary. Of the 88 constellations, 48 \u200b\u200bare in the southern hemisphere, and 31 in North. The remaining 9 groups of stars are located in both hemisphere. The northern hemisphere is easy to determine the polar star, which is always very brightly shine in the sky. She is an extreme star on a lattice lattice handle.
Due to the fact that the Earth rotates around the Sun, which does not give to see some constellations, the time of the year is shown and the position of this shine is changed in the sky. For example, in winter, the location of our planet in the near-oral orbit is the opposite of this summer. Therefore, every time of year you can see only certain constellations. For example, in the summer at the night sky, you can see the Altair, Vega and the Deb triangle formed by the stars. IN winter time There is an opportunity to admire the infinitely beautiful Constellation Orion. Therefore, sometimes they say: Autumn constellations, winter, summer or spring constellations.
Constellations are best visible in summer and desirable to observe them in the open space, outside the city. Some stars can be seen with a naked eye, and for some you may need a telescope. The constellations are best visible to a large and small bear, as well as Cassiopeia. In the fall and winter, the constellation of Taurus and Orion are clearly visible.
Bright constellations that are visible in Russia
The most beautiful constellations of the Northern Hemisphere, visible in Russia, are: Orion, Big Major, Taurus, Big Dog, Small Dog.
If you look at their location and give the will of fantasy, you can see the scene of hunting, which, as if on an ancient fresco, is captured by the sky for more than two thousand years. The brave Hunter Orion is always depicted surrounded by animals. Taurus runs to the right, and the hunter wakes up to him a bunch. At the legs of Orion is the right big and small dogs.
Constellation Orion
This is the biggest and colorful constellation. It is clearly visible in the fall and winter. Orion can be seen over the territory of all Russia. The location of his stars resembles a person's outlines.
The history of this constellation originates from the ancient Greek myths. According to them, Orion was a bold and strong hunter, the son of Poseidon and the Nymph Ember. He often hunted along with Artemida, but once, for the victory over her during the hunt, he was struck by an arrow of the goddess and died. After death, he was turned into a constellation.
The brightest star of Orion is a blower. She is 25 thousand times brighter and 33 times more of it in size. This star has a bluish-white glow and is considered to be supergiant. However, despite such impressive sizes, it is significantly less than Bethelgeuse.
Bethelgeuse decorates the right shoulder of Orion. It is 450 times larger than the diameter of the Sun and if they put on the place of our shining, then this star will take place four planets to Mars. Lights betelgeuse 14,000 times brighter than the sun.
In the Constellation, Orion also includes nebula and asterism.
Constellation Taurus
Another large and unimaginably beautiful constellation of the northern hemisphere is the Taurus. It is located in the north-west of Orion and is located between the constellations of Aries and Gemini. Not far from Taurus are located in such constellations as: arcing, whale, Perseus, Eridan.
This constellation in medium latitudes can be observed throughout almost the year, the exception is the second half of the spring and the beginning of the summer.
The history of the emergence of the constellation dates back to the ancient myths. They are said about the Zeus, who turned into a Taurus, in order to steal the goddess Europe and bring it to the island of Crete. For the first time, this constellation described Evdox - mathematician, who lived long before our era.
The brightest star is not only this constellation, but also the other 12 stars are Aldebaran. It is located on the head of the Taurus and before it was called "Eye". Aldebaran is 38 times larger than the diameter of the Sun and 150 times brighter it. This star is at a distance of 62 light years from us.
The second brightness of the star of constellation is NAT or El-Nat (bovine horns). It is located near the chapter. It brighter than the sun 700 times and more than 4.5 times.
Within the constellation there are two incredibly beautiful scattered clusters of giad stars and pleiades.
Hydy's age is 650 million years. They can easily find in the star sky thanks to Aldebaran, who is perfectly visible among them. Their composition includes about 200 stars.
Pleiades got their name thanks to nine parts. Seven of them are named after seven sisters of ancient Greece (Pleiad), and two more - in honor of their parents. Pleiades are very well visible in winter. They include about 1000 star bodies.
No less interesting education in the Constellation of Taurus is the crab-like nebula. It was formed after a supernova explosion in 1054 and was opened in 1731. The remoteness of the nebula from the Earth is 6,500 light years, and its diameter is about 11 sv. years.
This constellation refers to the Orion family and borders with the constellations Orion, unicorn, small dog, hare.
Constellation Big PSA For the first time was discovered by Ptolem in the second century.
There is a myth, according to which a big dog used to be Lelp. It was a very fast dog that could catch up with any prey. Once he chased the fox, who did not give him in speed. The result of the race was predetermined, and Zeus turned both animals into a stone. Psa he placed on the sky.
The constellation of large PSA is very clearly visible in winter. The brightest star is not only this, but also all other constellations is Sirius. It has a bluish glitter and is located pretty close to the ground, at a distance of 8.6 light years. In brightness in our solar system, Jupiter, Venus, Moon are superior to it. Light from Sirius reaches the ground after 9 years, and it is 24 times stronger than sunny. This star has a satellite called "puppy".
Syrius is associated with the formation of such a concept as "vacation". The fact is that this star appeared in the sky in the summer heat. Since Sirius is called "Kanisa" translated from Greek, then this period of the Greeks began to call the vacation.
Constellation small dog
A small dog is bordered with such constellations as: unicorn, hydra, cancer, twins. This constellation personifies the animal, which together with Big dog follows the Hunt Orion.
The history of the education of this constellation, if it is very interesting to rely on myths. According to them, a small dog is the mayor, a dog of Ikaria. This man taught to make Wine Dionysis and this drink was very strong. One day his guests decided that Ikaria decided to poison them and killed him. The mayor was very sad for the owner and soon died. Zeus placed him in the form of a constellation on the starry sky.
It is best to observe this constellation in January and February.
The most bright stars of this constellation are the portion and gomase. The portion is at a distance of 11.4 light years from the ground. He is a little brighter and hot sun, but physically little is different from him.
Gomase is visible to the naked eye and glows with white and blue light.
Constellation Big Mesmen.
The big bear, resembling the form of a bucket, is one of the three largest constellations. It is mentioned in the works of Homer and in the Bible. This constellation is very well studied and has great importance In many religions.
It borders with such constellations as: Welsh, lion, race tricks, dragon, lynx.
According to the ancient Greek myths, a large bear is associated with Callisto, beautiful nymph and a beloved Zeus. His Hera's wife in punishment turned Callisto to the bear. Once, this bear came across the forest on Giri and them with Zeus Son, Arkas. To avoid tragedy, Zeus turned his son and the Nymph in the constellation.
Big bucket form seven stars. The brightest of these are three: Duzhe, Alcaid, aliot.
Duzhe is a red giant and points to a polar star. It is 120 light years from the ground.
Alcaid, the third brightness of the star of the constellation, expresses the end of the tail of a big bear. From the ground it is at a distance of 100 light years.
Aliot is the brightest star in the constellation. She personifies the tail. Because of its brightness, it is applied in navigation. Alieot shines 108 times brighter than the sun.
These constellations are the most bright and beautiful in the northern hemisphere. They can be fine with the unarmed look in the autumn or frosty winter night. The legends of their formation allow you to raise fantasies and imagine how the mighty Hunter Orion, along with his faithful dogs, runs for prey, and the Taurus and Big Mesman carefully watch him.
Russia is located in the northern hemisphere, and in this part of the sky we manage to see only some of all the constellations in the sky. Depending on the time of year, only their position in the sky is changing.
Stars are not only a beautiful glow and landmark in the night sky, they are also the basis of any life. This confirms only one heavenly shovel - our sun, but does it confident, bringing light and warm us every day throughout many of many years. But what interesting facts about stars Are we still known?
1. All stars as much as they were not different, they are always from the same matter. In their initial state, 74% occupies hydrogen, 25% leaves under helium, and 1% make gaseous impurities of various kinds. Throughout its existence, the star gradually processes hydrogen and on the example of the Sun, in which this ratio is already 70% to 29%, this process is most convenient.
2. Among the interesting facts about the stars in space are the balance of their processes. In fact, gravity makes the heavenly body pull into itself, significantly decreasing in size, and it might lasts millions of years, until they become all like neutron stars, if it were not for light. Due to the constant thermonuclear reaction, it is produced and comes from the center itself, passing through it thousands of years, acting as gravity resistance.
3. The greatest number Among the stars are red dwarfs. They, as a rule, twice as smaller than our Sun and produce a small amount of energy, respectively - about 0.00001 from the possibilities of our shining. They are called failed, defective and internal hydrogen stock, they only have enough 10 trillion years.
4. An interesting fact about the stars in the sky. We are accustomed to thinking that the blue glow is cold, and orange and red light in turn are more like sources of heat. But in fact, the fire-red shtamilas have a minimal temperature - no more than 3,600 in Kelvin, and the blue is maximum - up to 12.000 in Kelvin.
5. At first glance it seems that every star in itself. But there are those that form a pair, while having a common gravitational center. But this is not the limit, scientists have found three, and four celestial bodies connected in one system. It is only worth imagining that instead of one sun we could have four.
6. Samoa big planet In our system is Saturn, he is truly huge, but there is a shine that could absorb him. They are called supergigants and one of the most famous is Bethelgei, it is 1000 times more than our sun. However, this is not a limit, because the most huge is considered to be VY a large dog, which is twice the most Bethelgeuse itself.
7. An interesting fact about planets and stars, if instead of our sun had something a little hot, a few million years of Mercury would simply appealed to the pairs.
8. Small heavenly luminaries finish their existence, forming white dwarfs, and the giants in turn leave behind black holes.
9. Despite the inconceivable number of giant giants that they surround us, all of them are very and very far away. The closest to us is called proxima Centauri and before it from the ground about four and a half light years. That is, the ray of light will be able to overcome this distance in such a time, which concerns a person, then on the most incredible fast space ship He would need at least 70 thousand years, which makes travels between the luminaires simply impossible at the moment.
10. How many stars exist? It is extremely difficult to calculate it, and maybe it is even impossible, because only in our galaxy their average is 300 billion. And the whole galaxies can be 500 billion and in each approximately as many giants, which makes the total number rather frightening.
It is unlikely that there is such a person who never admired the stars, looking at the shimmering night sky. They can be admired forever, they are mysterious and attractive. In this thread you will get acquainted with the unusual facts about the stars and learn a lot of new
Do you know that most stars you consider at night are double stars? Two stars are circling each other, creating a point of gravity, or a smaller star goes around a big "main star". Sometimes these main stars pull the matter from smaller during the rapprochement with each other. There is a mass limit that the planet can withstand, without causing a nuclear reaction. If Jupiter were big, then it would probably turn into a brown dwarf, a kind of semi-shots, a lot of my moon 
Such processes often occur in other solar systems, which is confirmed by the lack of planets in them. Most of the matter that is in the field of the main star is collected in one place, as a result, forming a new star and binary system. In one system there may be more than two stars, but still binary numbering systems are widespread
White dwarfs, so-called "dead stars." After the red giant phase, our own star - the sun - will also become white dwarf. White dwarfs have a radius of the planet (like the Earth, not as Jupiter), but the density of the star. Such specific weights are possible due to electrons separated from the atomic nuclei that they surround. As a result, the number of space that these atoms occupy and is created large mass With a small radius 
If you could keep the atom core in our hand, the electron would be spinning around you at a distance of 100 meters or more. In the case of electron degeneration, this space remains free. As a result, the White Dwarf cools and stops emitting light. These massive bodies cannot be seen, and no one knows how many of them are in the universe.
If the star is large enough to avoid the final white dwarf phase, but too small to avoid turning into a black hole, the exotic type of stars, known as a neutron star, will be formed. The process of formation of neutron stars is somewhat similar to white dwarfs, in which they also gradually degrade - but differently. Neutron stars are formed from the worsening matter of the so-called neutron, when all electrons and positively charged protons are eliminated, and only neutrons form the base of the star. The density of the neutron star is comparable to the density of the atomic nuclei.
Neutron stars may have a mass like our Sun or a little higher, but their radius is less than 50 kilometers: usually 10-20. The teaspoon of this neutron exceeds 900 times the mass of a large pyramid in Giza. If you observed a neutron star directly, we would see both poles, because the neutron star works as a gravitational lens, flexing the light around itself thanks to the most powerful gravity. A special case Neutron Star - Pulsar. Pulsars can rotate with a speed of 700 revolutions per second, the emitting flashing radiation - from here and their name 
Eta Carinae - one of the most big starfound at the moment. It is 100 times heavier than our sun and has approximately the same radius. Eta Carinae can shine in a million times brighter than the sun. Usually these hypermassive stars exist quite shortly, because they literally burn themselves, so they are called supernov. Scientists believe the limit is the mass, 120 times higher than the mass of the Sun - no star can weigh. 
Star Pistol - Hypergigant, similar to Eta Carinae, who does not have the opportunity to cool himself. The star is so hot that it is barely held in holistic form due to its gravity 
As a result, the star Pistol eats the so-called "sunny wind" (high particles of energy that, for example, create Northern Lights). It shines 10 billion times stronger than our sun. Due to massive levels of radiation, it is impossible to even assume that in this star system will ever be able to exist
In this thread, I set out the most interesting facts about the stars, which could only find. I hope you were interested
Used the rank to us - this The sun. It is described in detail on a separate page. Here we will talk about the stars in general, that is, including those that you can see at night.
We will not exclude the sun either from the narration, on the contrary, we will always compare other stars with him. To the Sun - 150,000,000 kilometers. It is 270,000 times closer than to the closest, excluding the sun itself, the stars. It is clear why a lot of things are known about the stars, we know thanks to our day luminaries.
Even light from the nearest stars is several years old, and the stars themselves in the most powerful telescopes are visible as points. However, it is not quite so: the stars are visible in the form of tiny disks, but this is due to distortions in telescopes, and not with increasing. Stars countless. No one is able to say exactly how many stars, the more the stars are born and die. One can only approximately declare that in our galaxy about 150,000,000,000 stars, and in the universe, an unknown number of billion galaxies ... But how many stars can be seen in the sky it is known more accurate: about 4.5 thousand. Moreover, by setting a certain limit of the brightness of stars, close in accessibility, you can call it more precisely, almost to units. The bright stars are long counted and listed in the catalogs. The brightness of the star (or, as they say, its shine) is characterized by the star magnitude, which the astronomers have long been able to determine. So what is the stars?
Stars - Hot Gas Balls. The temperature of the surface of the stars is different. In some stars, it can reach 30,000 K, and others have only 3 000k. Our sun has a surface with a temperature of about 6,000 K. It is necessary to make a reservation, which speaking about the surface, we mean only the visible surface, since there can be no solid surface at the gas ball.
Normal stars are much more planets, but the main thing is much more massive. We will see that there are strange stars in the universe, having typical sizes typical of the planets, but many times superior to the latter by weight. The sun is 750 times massive than all other bodies Solar system. More about the size of the planets, asteroids and comets and about them you can learn on the pages dedicated to the solar system. There are stars, hundreds of times greater than the Sun in size and in the same time inferior to him in this indicator. However, the masses of stars change in much more modest limits - from one twelfth mass of the Sun to 100 of its mass. Maybe there are more hard, but such massive stars are very rare. It is not difficult to guess by reading the last strings that the stars are very different in density. There are among them such, the cubic centimeter of which outweighs a large loaded ocean ship. The substance of other stars is so discharged that its density is less than the density of the best vacuum, which is achievable in earthly laboratory conditions. We will return to the conversation about the size, masses and density of stars in the future.
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Immediateness of the centuries man tried to give the name of objects and phenomena that surrounded him. This also applies to heavenly bodies. First, the names received the brightest, well visible stars, over time - and others.
Some stars got the names in accordance with the situation they occupy in the constellation. For example, in the constellation of the Swan Star Denief (the word is translated as "tail") is indeed deployed in this part of the body of the imaginary swan. One more example. Star Omicron, she is more famous called the world, which is translated from Latin as "amazing", is in the Constellation of China. The world has the ability to change its brightness. For long periods, she generally disappears from the field of view, refers to the observation by the unarmed eye. The name of the star and is explained by its specificity. Mostly stars got the names in the era of antiquity, so there is nothing surprising in the fact that most names have Latin, Greek, and later Arab roots.
The opening of the stars, the visible brilliance of which changes with time, led to special notation. They are indicated by the capital latin letters, followed by the name of the constellation in the parental case. But the first variable star, found in some constellation, is not indicated by the letter A. The countdown is conducted from the letter R. The next star is denoted by the letter S and so on. When all the letters of the alphabet are exhausted, a new circle begins, that is, after Z, A is again used. In this case, letters can double, for example, "RR". "R lion" means that this is the first open star variable in the constellation of the lion.
How a star is born.
Stars are born when the cloud consisting mainly of the interior gas and dust is compressed and compacted under the action of its own gravity. It is believed that this particular process leads to the formation of stars. Using optical telescopes, astronomers can see these zones, they look like dark spots on a bright background. They are called "gigantic complexes of molecular clouds", because hydrogen is included in their composition in the form of molecules. These complexes, or systems, along with ball-star closures, are the largest structures in the galaxy, their diameter sometimes reaches 1300 light years.
More young stars, they are called the "star population I", were formed from the remains of the outbreaks of the old stars, they are called the "Star Population II". The outbreak of an explosive causes a shock wave, which comes to the nearest nebula and provokes its compression.
Globus Boca .
So, the compression of the part of the nebula occurs. At the same time, the formation of dense dark gas damp clouds is begins the formation of dense dark gas damp. They are called "Boc Globes". Side - American astronomer of Dutch origin (1906-1983) - first described globules. The mass globul is about 200 times higher than the mass of our sun.
As the Gullary of the Boca continues to thicken, its mass increases, attracting to himself thanks to the gravity of matter from the neighboring regions. Due to the fact that the inner part of the globule is condensed faster than the external, the globule begins to heal and rotate. After a few hundred thousand years, during which compression occurs, the protocol is formed.
The evolution of the protocol.
Due to the increase in the mass to the center of the protocol, more and more matter is attracted. The energy released from the compressive inside the gas is transformed into heat. Pressure, density and temperature of the protostar rises. Due to the increase in temperature, the star begins to glow dark-red light.
The protocol has very large sizes, and although thermal energy is distributed throughout its surface, it still remains relatively cold. In the kernel, the temperature grows and reaches several million degrees Celsius. The rotation and the round shape of the protosal are somewhat modified, it becomes more flat. This process lasts millions of years.
It is difficult to see young stars, as they are still surrounded by a dark dust cloud, because of which the star's shine is practically not visible. But they can be considered using special infrared telescopes. The hot core of the protocol is surrounded by a rotating disk from the matter with a great strength of attraction. The core is so warming up that it begins to throw away the matter from two poles, where the resistance is minimal. When these emissions face an interstellar medium, they slow down movement and dispel on both sides, forming a cap-like or arcoolent structure, known as the "Herbian Haro object".
Star or Planet?
The temperature of the protoster comes to several thousand degrees. Further development of events depends on the dimensions of this celestial body; If the mass is small and is less than 10% of the mass of the Sun, it means that there are no conditions for the passage of nuclear reactions. Such a protocol will not be able to turn into a real star.
Scientists calculated that in order to convert the compressive celestial body in the star, its minimum mass should be at least 0.08 of the mass of our sun. The gas-containing cloud of smaller sizes, condensed, will gradually cool and turn into a transitional object, something average between the star and the planet is the so-called "brown dwarf".
Planet Jupiter is a heavenly object of too small in order to become a star. If he were more, nuclear reactions began in his depths, and he would find the emergence of a system of double stars.
Nuclear reactions.
If the mass of the protozoa is big, it continues to thicken under the action of their own gravity. The pressure and temperature in the nucleus are growing, the temperature gradually comes to 10 million degrees. This is sufficient to connect hydrogen and helium atoms.
Next is activated " nuclear reactor"Proclections, and it turns into an ordinary star. Then there is a strong wind, which accelerates the surrounding shell of dust. After that, you can see the light emanating from the resulting star. This stage is called the "T-Tel Phase", it can last 30 million years. From the remains of gas and dust surrounding the star, the formation of planets.
Birth new Star May cause a shock wave. Having reached the nebula, it provokes the condensation of new matter, and the process of stars will continue through gas-pepped clouds. The small stars are weak and cold, the largest - hot and bright. Most of its existence, the star balanced in the equilibrium stage.
Characteristics of stars.
Observing the sky even with a naked eye, you can immediately note this feature of the stars as brightness. Some stars are very bright, others are weaker. Without special devices in ideal visibility conditions, about 6000 stars can be considered. Thanks to the binoculars or telescope, our capabilities increase significantly, we can admire the millions of the stars of the Milky Way and external galaxies.
Ptolemy and Almagest.
The first attempt to draw up the catalog of the stars, based on the principle of the degree of their luminosity, took the Ellinsky astronomer of Hipparch from Nicea in the II century BC. Among his many works, the star catalog appeared, containing a description of 850 stars classified by coordinates and luminosity. Data collected by Hpanchu, and he, besides this, opened the phenomenon of precession, were worked out and received further development Thanks to Claudia Ptolemy from Alexandria in II century. AD He created the Fundamental Opus "Almagest" in thirteen books. Ptolemy collected all the astronomical knowledge of the time, classified them and outlined in an affordable and understandable form. In Almagest, the Star Catalog entered. It was based on the observations of Hippark, made four centuries ago. But the "star catalog" Ptolemy contained about a thousand stars more.
The Ptolemy catalog used almost everywhere during the Millennium. He divided the stars into six classes according to the degree of luminosity: the brightest were attributed to the first class, less bright - to the second and so on.
The sixth grade includes stars, barely distinguished by the naked eye. The term "the power of the glow of heavenly bodies" is used and at present to determine the measure of the gloss of celestial bodies, and not only stars, but also nebulae, galaxies and others heavenly phenomena.
Starry value in modern science.
In the middle of the XIX century. English Astronomer Norman Pogson improved the method of classification of stars on the principle of luminosity, which existed since the times of Hippark and Ptolemy. Pusson was considered that the difference in terms of luminosity between two classes 2.5. Pogon introduced a new scale, according to which the difference between the stars of the first and sixth grades is 100 AE. That is, the attitude of the brilliance of stars of the first star magnitude is 100. This ratio corresponds to the interval of 5 star magnitudes.
Relative and absolute star magnitude.
Star magnitude measured using special devices mounted in a telescope indicates how much the star of the star comes to an observer on the ground. The light overcomes the distance from the star to us, and, accordingly, the farther the star is, the more weaker it seems. That is, when determining the star magnitude, it is necessary to take into account the distance to the star. In this case, we are talking about the relative starry value. It depends on the distance.
There are stars very bright and very weak. To compare the brightness of the stars, regardless of their distance, the idea of \u200b\u200bland was introduced by the concept of "Absolute Star Value". It characterizes the star's shine at a certain distance in 10 parses (10 parses \u003d 3.26 light year). To determine the absolute star magnitude, you need to know the distance to the star.
Color stars.
The next important star characteristic is its color. Considering the stars even with a naked eye, it can be noted that not all of them are the same.
There are blue, yellow, orange, red stars, and not just white. The color of the stars say a lot of astronomers, first of all, it depends on the temperature of the star surface. Red stars are the coldest, their temperature is approximately 2000-3000 about S. Yellow stars, like our sun, have an average temperature of 5000-6000 about C. The hottest - white and blue stars, their temperature is 50000-60000 about C and higher .
Mysterious lines.
If you skip the light of the stars through the prism, we get the so-called spectrum, it will cross the lines. These lines are a kind of "Identification card" of the star, since the astronomers can determine the chemical composition of the surface layers of the stars. Lines belong to various chemical elements.
Comparing lines in a star spectrum with lines made in laboratory conditions, you can determine which chemical elements are part of the stars. In the spectra, the mains of hydrogen and helium are the mains, it is these elements that constitute the bulk of the star. But it is also elements of a group of metals - iron, calcium, sodium, etc. In a sunny bright spectrum, the lines of almost all are visible chemical elements.
Charterssprung-Resell chart.
Among the parameters characterizing the star, there are two most important things - these are temperatures and an absolute star. Temperature indicators are closely related to the color of the star, and the absolute star value is with a spectral class. This refers to the classification of stars on the intensity of the lines in their spectra. According to the currently used classification, the stars in accordance with their spectra are divided into seven main spectral classes. They are marked with Latin letters O, B, A, F, G, K, M. It is in this sequence that the temperature of the stars decreases from several tens of thousands of degrees class O to 2000-3000 degrees of the stars of type M.
Absolute Star Value, i.e. Mera glitter, indicates the amount of energy emitted by the star. It can be calculated theoretically, knowing the distance of the stars.
Outstanding idea.
The idea of \u200b\u200btie to each other two main parameters of the star came to the head of two scientists in 1913, and they were carried out independently of each other.
We are talking about the Dutch astronomer Einar Herzshprung and American astrophysics Henry Norris Resess. Scientists worked at a distance of thousands of kilometers from each other. They made a schedule tied together two main parameters. The horizontal axis reflects the temperature vertical - an absolute star. As a result, a diagram was obtained, which were assigned the names of two astronomers - the Herzshprung-Resell chart, or, easier, the diagram Mr.
Star - criterion.
Let's see how the Mr. diagram is compiled. First of all, you need to select a star criterion. For this, a star is suitable, the distance to which is known, or the other - with an already calculated absolute star magnitude.
It should be borne in mind that the intensity of the luminosity of any source, whether it is a candle, a light bulb or a star, varies depending on the distance. It is mathematically expressed: the intensity of the luminosity "I" at a certain distance "D" from the source is inversely proportional to "D2". Almost this means that if the distance increases twice, the intensity of luminosity decreases four times.
Then, determine the temperature of the selected stars. For this you need to identify them spectral class, color and then determine the temperature. Currently, instead of spectral type, another indicator equivalent to it is "color index".
These two parameters are applied to one plane with a temperature dropped from left to right, on the abscissa. Absolute luminosity is fixed on the ordinate, the increase is noted from the bottom up.
Home sequence.
On the Diagram, Mr. Stars are located along the diagonal line, reaching the bottom and left to the right. This strip is called the main sequence. The stars included in its composition are called stars of the main sequence. The sun applies to this group. This is a group of yellow stars with a surface temperature of approximately 5600 degrees. Stars of the main sequence are in the most "quiet phase" of their existence. In the depths of their nuclei atoms of hydrogen are mixed, helium is formed. The phase of the main sequence is 90% of the existence of the star. Of the 100 stars 90 are precisely in this phase, although they are distributed from different positions depending on temperature and luminosity.
The main sequence is a "narrow area", it suggests that the stars are difficult to retain the balance between the force of attraction, which pulls inside, and the force generated as a result of nuclear reactions, it pulls to the outside of the zone. The star similar to the Sun, equal to 5600 degrees, should have an absolute star magnitude of order +4.7. This follows from the Mr. diagram.
Red giants and white dwarfs.
The red giants are located in the upper zone on the right, located on the outside of the main sequence. A characteristic feature of these stars is a very low temperature (approximately 3000 degrees), but at the same time they are brighter stars having an identical temperature and located in the main sequence.
Naturally, the question arises: if the energy emitted by the star depends on the temperature, then why the stars with the same temperature have different degrees of luminosity. The explanation should be sought in the amount of stars. The red giants are brighter because their radiating surface is much larger than that of the stars from the main sequence.
It is no coincidence that this type of stars got the name "Giants". Indeed, their diameter can exceed 200 times the diameter, these stars can occupy space 300 million km, which twice the distance from the ground to the Sun! With the help of the position about the influence of the star, we will try to explain some points in the existence of other stars - white dwarfs. They are located downstairs to the left in the Mr. diagram.
White dwarfs - very hot, but not at all bright stars. At the same temperature with large and hot white-blue stars of the main sequence, white dwarfs are much smaller in size. These are very dense and compact stars, they are 100 times smaller than the sun, their diameter is about the same as the earth. You can bring a bright example of a high density of white dwarfs - one cubic centimeter of matter, from which they consist, should weigh about one ton!
Ball stars clusters.
When drawing up diagrams Mr. Sharov Star clusters, and they are basically the oldest stars in them, it is very difficult to determine the main sequence. Its traces are fixed mainly in the lower zone where coolest stars are concentrated. This is due to the fact that the hot and bright stars have already passed the stable phase of their existence and move to the right, to the zone of red giants, and if it was passed, then in the white dwarf zone. If people were able to trace their lives all the evolutionary stages of the star, they would be able to see how she change their characteristics.
For example, when the hydrogen in the star core stops burning, the temperature in the outer layer of the stars decreases, the layer itself expands. The star comes out of the main sequence phase and heads to the right side of the chart. This applies primarily by major stars, the most striking, it is this type that evolves faster.
Over time, the stars come out of the main sequence. The diagram is recorded "Turning Point" - "Rotary Point", due to it, it is possible to quite accurately calculate the age of stars of clusters. The higher the chart is the "swivel point", the younger cluster, and, accordingly, the lower on the diagram it is, the older in the age of the star cluster.
Diagram value.
The Herzshprung-Resesslla chart provides tremendous assistance in learning the evolution of the stars throughout their existence. During this time, the stars are changing, transformations, in some periods they are very deep. We already know that the stars are not different from their own characteristics, but by the types of phases in which they are at one time or another.
Using this diagram, you can calculate the distance to the stars. You can choose any star in the main sequence, with the already defined temperature and see its promotion on the diagram.
Dissasting to stars.
When we look at the sky with a naked eye, the stars, even the brightest, seem to us with brilliant dots, located on the same distance from us. Heavenly arch spread over us as a carpet. It is no coincidence that the stars position are expressed only in two coordinates (direct climbing and declining), and not in three, as if they are located on the surface, and not three-dimensional space. With the help of telescopes, we cannot get all the information about the stars, for example, by photographs of the Hubble Space Telescope, we cannot accurately determine at what distance the stars are.
Space depth.
The fact that the Universe has a third dimension - depth, - people learned relatively recently. Only in early XIX. Again, due to the improvement of astronomical equipment and tools, scientists were able to measure the distance to some stars. The first was the star 61 swan. Astronomer F.V. Bessel found that it is at a distance of 10 light years. Bessel was one of the first astronomers measured "one-year pararallax". To date, the method of "one-year parallax" underlies the distance to the distances to the stars. This is a pure geometric method - just measure the angle and calculate the result.
But the simplicity of the method does not always correspond to performance. Due to the high remoteness of the stars, the corners are very small. They can be measured using telescopes. The corner of the parallax star of the proxima Centauro, the closest of the triple system of Alfa Centaurus, a small (0.76 accurate option), but at such an angle can be considered a coin in a hundred lira at a distance of a tens of kilometers. Of course, the further the distance, the less the angle becomes.
Inevitable inaccuracies.
Errors in terms of determination of parallax are quite possible, and their number increases as an object deletes. Although, with the help of modern telescopes, you can measure the angles with an accuracy of a thousandth, errors will still be: at a distance of 30 light years, they will be about 7%, 150 s. years - 35%, and 350 sv. years - up to 70%. Of course, large inaccuracies make measurements useless. Using the "Parallax method", you can successfully determine the distances of up to several thousand stars located in the area of \u200b\u200babout 100 light years. But in our galaxy there are more than 100 billion stars, the diameter of which is 100,000 light years!
There are several options for the "one-year parallax" method, for example, the "age pararallax". The method takes into account the movement of the Sun and the entire solar system in the direction of the constellation of Hercules, at a speed of 20km / s. With this movement, scientists have the ability to assemble the necessary database for the successful calculation of parallax. For ten years, information was obtained 40 times more than it was possible.
Then, using trigonometric calculations, the distance to a certain star is determined.
Distance to starred clusters.
It is easier to calculate the distance to star clusters, especially scattered. Stars are relatively close from each other, therefore, calculates the distance to one star, you can determine the distance to the entire star cluster.
In addition, in this case you can use statistical methodsallowing to reduce the number of inaccuracies. For example, the method of "converging points", it is often used by astronomers. It is based on the fact that with long-term observation of the stars of scattered accumulation, moving to a common point is distinguished, it is called a converging point. Measuring, angles and radial speeds (i.e. speeds of approaching land and removal from it), you can determine the distance to star cluster. When using this method, 15% of inaccuracies are possible at a distance of 1500 light years. It is used and at distances of 15,000 light years, which is quite suitable for heavenly bodies in our galaxy.
Main. Sequence Fitting. - establishing the main sequence.
To determine the distance to distant star clusters, for example, Pleiad, can be done as follows: Build diagram Mr., on the vertical axis, note the visible star magnitude (and not absolute, because it depends on the distance), depending on the temperature.
Then you should compare the resulting picture with the Mr. Maid diagram, it has many common features in terms of main sequences. By combining two charts as close as possible, you can define the main sequence of star cluster, the distance to which you need to measure.
Then the equation should be used:
m-m \u003d 5log (d) -5, where
m - visible star quantity;
M is an absolute star value;
d - distance.
In English, this method is called "Main Sequence Fitting". It can be used to such scattered star clusters, like NGC 2362, Alpha Persea, III Cefhea, NGC 6611. The astronomers have attempted to determine the distance to the famous double scattered star cluster in the constellation Perseus ("H" and "Chi"), where many stars are located -Severtigigants. But the data turned out to be contradictory. Using the Main Sequence Fitting method it is possible to determine the distance to 20,000-25,000 light years, this is the fifth of our galaxy.
The intensity of light and distance.
The farther there is some kind of heavenly body, thedes seems weaker. This provision is consistent with the optical law, in accordance with which the intensity of light "I" is inversely proportional to the distance erected into the square "D".
For example, if any galaxy is at a distance of 10 million light years, then another galaxy, located in 20 million light years, has a shine four times smaller compared to the first. That is, from a mathematical point of view, the connection between the two values \u200b\u200b"I" and "D" is accurate and measurable. Speaking by the language of astrophysics, the intensity of light is the absolute value of the star magnitude M of any celestial object, the distance to which should be measured.
Using the M-M-M \u003d 5Log (D) -5 equation (it reflects the law on shine change) and knowing that M can always be determined using a photometer, and M is known, the distance "D" is measured. So, knowing the absolute star value, with the help of calculations, it is not difficult to determine the distance.
Interporing absorption.
One of the main problems associated with distance measurement methods is the problem of light absorption. On the way to Earth, the light overcomes huge distances, it passes through the inter-storage dust and gas. Accordingly, part of the light is adsorbed, and when it comes to the telescopes installed on the ground, already has a non-vigorous force. Scientists call it "extinction", weakening light. It is very important to calculate the amount of extinction when using a number of methods, for example, candel. At the same time, exactly absolute star values \u200b\u200bshould be known.
It is easy to identify extinction for our galaxy - just take into account the dust and the Milky Way gas. It is more difficult to determine the extinction of light from the object from another galaxy. To extinction along the path in our galaxy, some of the absorbed light from another should be added.
Evolution of stars.
The inner life of the star is regulated by the impact of the two forces: the strength of attraction, which counteracts the star, keeps it, and the forces exempted by nuclear reactions occurring in the kernel. She, on the contrary, seeks to "push out" the star into a long space. During the formation stage, a dense and compressed star is under strong influence of gravity. As a result, severe heating occurs, the temperature reaches 10-20 million degrees. This is enough to start nuclear reactions, as a result of which hydrogen turns into helium.
Then for a long period, two forces balancing each other, the star is in a stable state. When the nuclear fuel is gradually runs out, the star enters the phase of instability, the two forces configure. For the star comes a critical moment, a variety of factors come into effect - temperature, density, chemical composition. The first place is the mass of the star, it is from her that the future of this celestial body depends - or the star will break up like a supernova, or will turn into white Dwarf, neutron star or black hole.
How hydrogen is dried.
Only very large among heavenly bodies become stars, smaller become planets. There are also body of medium mass, they are too large to relate to the class of planets, and too small and cold to make nuclear reactions characteristic of stars.
So, the star is formed from clouds consisting of interstellar gas. As already noted, pretty for a long time Star is in a balanced state. Then the period of instability occurs. Further fate Stars depends on various factors. Consider a hypothetical star of a small size, the mass of which ranges from 0.1 to 4 solar masses. A characteristic feature of stars having a small mass is the lack of convection in internal layers. The substances that are part of the star are not mixed as it happens in stars with a large mass.
This means that when hydrogen ends in the kernel, there are no new stocks of this element in the outer layers. Hydrogen, burning, turns into helium. A little bit of the core is heated, the surface layers destabilize their own structure, and the star, as can be seen in the Mr. diagram, slowly comes out of the main sequence. In the new phase, the density of matter inside the star rises, the composition of the kernel "degenerates", as a result, a special consistency appears. It differs from normal matter.
Modifying matter.
When matterium is modified, the pressure depends only on the density of the gases, and not on temperature.
On the Herzshprung-Resevel chart, the star shifts to the right, and then up, approaching the area of \u200b\u200bthe red giants. Its dimensions increase significantly, and due to this, the temperature of the outer layer falls. The diameter of the red giant can reach hundreds of millions of kilometers. When our sun goes into this phase, it will "swallow" and Mercury and Venus, and if it cannot capture the earth, it will warm it up to such an extent that life on our planet will cease to exist.
During the evolution of the star, the temperature of its kernel rises. First, nuclear reactions occur, then helium melting begins to achieve the optimal temperature. When this happens, a sudden increase in the temperature of the kernel causes a flash, and the star moves quickly into left part Diagrams Mr. This is the so-called "Helium Flash". At this time, the kernel containing helium burns together with hydrogen, which is part of the shell surrounding the core. On the Mr. Diagram, this stage is fixed by the advancement of the horizontal line to the right.
The latest phases of evolution.
When a helium transformation into a hydrocarbon core is modified. Its temperature rises until carbon starts to burn. There is a new flash. In any case, during the last phases of the evolution of the star, there is a significant loss of its mass. It can occur gradually or sharply, during the outbreak, when the external stars of the star burst like a big bubble. IN last case A planetary nebula is formed - a spherical form shell, propagating in outer space at a speed of several dozen or even hundreds of km / s.
The ultimate fate of the star depends on the mass remaining after all that happens to it. If, during all transformations and outbreaks, it has thrown a lot of matter and its mass does not exceed 1.44 solar mass, the star turns into white dwarf. This name is the name "Candrasen Limit" in honor of Pakistani astrophysics of Substramanyan Chandrasen. This is the maximum mass of a star, in which a catastrophic end may not be taken due to the pressure of electrons in the kernel.
After the outbreak of the outdoor layers of the star, the star remains, and its surface temperature is very high - about 100,000 about K. The star moves to the left edge of the Mr. diagram and descends down. Its luminosity decreases, as dimensions decrease.
The star slowly comes to the white dwarf zone. These are small diameter stars, but distinguished by very high density, one and a half million times more water density.
White dwarf is the final stage of the evolution of the star, without flares. She gradually cools. Scientists believe that the end of the white dwarf passes very slowly, in any case, from the beginning of the existence of the universe, it seems that no White Dwarf has suffered from "thermal death."
If the star is large, and its mass is more than the sun, it will break up like a supernova. During the outbreak, the star can collapse completely or partially. In the first case, it will remain a gas cloud with the residual stars. In the second, the heavenly body of the highest density remains - a neutron star or a black hole.
Variable stars.
According to the concept of Aristotle, the celestial bodies of the Universe are eternal and permanent. But this theory has undergone significant changes with the appearance in the XVII century. first binoculars. Observations conducted during the following centuries have demonstrated that in reality, the apparent constancy of the celestial bodies is due to the lack of equipment for observation or its imperfection. Scientists concluded that changeability is overall characteristic All types of stars. During the evolution, the star passes several stages, during which its main characteristics - color and luminosity - undergo deep changes. They occur during the existence of the star, and these are dozens or hundreds of millions of years, therefore a person cannot be an eyewitness of what is happening. Some classes of stars occurring changes are fixed in short periods of time, for example for several months, days or parts of the day. Changes in the star changes, its light streams can be messed repeatedly for subsequent nights.
Measurements.
In fact, this problem is not so simple, as it seems at first glance. When measuring, the atmospheric conditions must be taken into account, and they change, and sometimes significantly for one night. In this regard, the data on the lights of the stars differ significantly.
It is very important to be able to distinguish these changes in the light flux, and they are directly related to the stars glitter, from the apparent, they are explained by changing atmospheric conditions.
To do this, it is recommended to compare the light fluxes of the observable star with other stars - guidelines visible to the telescope. If the changes are apparent, i.e. associated with a change in atmospheric conditions, they touch all the observed stars.
Get the right data about the status of the star on the Koki stage is the first step. Next, it is necessary to create a "shine curve" to record possible shine changes. It will show a change in star magnitude.
Variables or not.
Stars, the star magnitude of which is inconstant, called variables. Some of them have changeability only apparent. These are mainly stars related to the double system. At the same time, when the orbital plane of the system more or less coincides with the beam of the observer, it may seem to him that one of the two stars is completely or partially eclipsed by another and is less bright. In these cases, changes are periodic, periods of changes in the shine of eclipse stars are repeated with an interval that coincides with the orbital period of the dual stars. These stars are called "Estimated Variables".
The following class of stars variable is "internal variables." The amplitudes of the oscillations of the shine of these stars depend on the physical parameters of the star, for example, from radius and temperature. For many years, astronomers led to the variability of stars. Only in our galaxy recorded 30,000 star variables. They were divided into two groups. The first includes "erupical variables of stars." They are characterized by single or repeating outbreaks. Changes in star magnitudes Epizodichna. The class of "eructural variables", or explosive, also includes new and supernova. The second group is all the rest.
Cefeida.
There are variable stars, the glitter of which changes strictly periodically. Changes occur at certain intervals. If you make a shine curve, it will clearly fix the regularity of the changes, while the form of the curve will notice the maximum and minimum characteristics. The difference between the maximum and minimum oscillations determines the large space between the two characteristics. Stars of this type belong to the "variable pulsating". On the gloss curve, it can be concluded that the shine of the star increases faster than decreases.
Variable stars are divided into classes. The prototype star is taken for the criterion, it is she gives the name of the class. Cefeida can be brought as an example. This name comes from the star Cefhea. This is the easiest criterion. There are other - the stars are divided into spectra.
Variable stars can be divided into subgroups in different criteria.
Double stars.
Stars on the celestial arch existed in the form of clusters, association, and not as single bodies. Star clusters can be littered with stars very thick or not.
There may be closer ties between the stars, we are talking about double systems as astronomers are called. In a pair of stars, evolution alone directly affects the second.
Opening.
The discovery of double stars, at present they are called that are so called one of the first discoveries carried out with the help of astronomical binoculars. The first pair of this type of stars became Mitsar from the constellation of a large bear. Opening made Italian astronomer Riccholi. Given the huge number of stars in the universe, scientists came to the conclusion that Mitsar among them is not the only dual system, and were right, soon the observation was confirmed by this hypothesis. In 1804, William Herschel, known by Astronomer, who devoted 24 years to scientific observations, published a directory comprising a description of about 700 double stars. Initially, scientists did not know exactly if the components of the double system are physically connected with each other.
Some bright minds believed that double stars A starry association is operating in general, especially in a pair of brilliance of components was not the same. In this regard, the impression was created that they were not near. To clarify the true position of the bodies, it was necessary to measure the parallact displacements of the stars. This was engaged in Herschel. To the greatest surprise, the parallact displacement of one star towards the other during the measurement gave an unexpected result. Herschel noticed that instead of symmetric oscillations with a period of 6 months, each star follows the complex ellipsoid path. In accordance with the laws of heavenly mechanics, two bodies associated with the power of attraction move along an elliptical orbit. Herschel's observations confirmed the thesis that the double stars are physically connected, that is, forces.
Classification of double stars.
Three main class of double stars are distinguished: visual-double, double photometric and spectral-dual. This classification does not fully reflect the internal differences in the classes, but gives an idea of \u200b\u200bthe star association.
The duality of visual-double stars is clearly visible to the telescope as they are moved. Currently, about 70,000 visual-doubles is identified, but only 1% of them were accurately defined orbit.
Such a digit (1%) should not be surprised. The fact is that orbital periods can be several decades, unless there are centuries. And to build a way in orbit - very painstaking work, requiring numerous calculations and observations from different observatories. Very often, scientists have only fragments of the orbit movement, the rest of the path they restore the deductive method using the available data. It should be borne in mind that the orbital plane of the system can be tilted to the beam of view. In this case, the recreated orbit (visible) will differ significantly from the true one.
If the true orbit is defined, the period of circulation and the angular distance between the two stars is known, can, applying the third Capler's law, determining the sum of the mass components of the system. The distance of the double stars to us should also be known.
Double photometric stars.
On the duality of this system of stars can be judged only in periodic gloss fluctuations. When moving, such stars are alternately blocked each other. They are also called "elaborate-dual stars." These stars the plane of the orbits are close to the direction of the beam of sight. The larger area occupies an eclipse, the more pronounced shine. If you analyze the gloss curve of double photometric stars, you can determine the inclination of the orbital plane.
Using the gloss curve, you can determine the orbital period of the system. If, for example, two eclipses are fixed, the shine curve will have two decline (minimum). The period of time for which three consecutive decreases on the gloss curve corresponds to the orbital period.
Periods of double photometric stars are much shorter than the periods of visual-dual stars and make up a period of several hours or a few days.
Spectral-dual stars.
Using spectroscopy, you can notice the splitting of spectral lines due to the Doppler effect. If one of the components is a weak star, then only the periodic oscillation of the positions of single lines is observed. This method is used in the case when the components of the double star are very close to each other and it is difficult to identify using a telescope as visual-dual stars. Double stars, determined by the spectroscope and the Doppler effect, are called spectral-dual. Not all double stars are spectral. Two components of double stars can be given and approach the radial direction.
Observations suggest that the double stars are found mainly in our galaxy. It is difficult to determine the percentage ratio of double and single stars. If you act in the method of subtracting and from the entire star population to subtract the number of identified double stars, it can be concluded that they constitute a minority. This conclusion may be erroneous. In astronomy, there is the concept of "Effect of Selection". To determine the duality of the stars, it is necessary to identify their main characteristics. For this you need good equipment. Sometimes it is difficult to define double stars. For example, visual-dual stars can not always be seen on a high distance from the observer. Sometimes the angular distance between the components is not fixed by the telescope. In order to fix photometric and spectral-dual stars, their shine should be strong enough to collect the modulation of the light stream and thoroughly measure the wavelength in the spectral lines.
The number of stars suitable in all parameters for research is not so large. According to theoretical developments, it can be assumed that the dual stars range from 30% to 70% of the star population.
New stars.
Variables explosive stars consist of white dwarf and the stars of the main sequence, like the sun, or post-sequence, like a red giant. Both stars follow a narrow orbit with a frequency of several hours. They are close to each other, and therefore they interact closely and cause spectacular phenomena.
From the middle of the XIX century, scientists fix on the optical strip of variable explosive stars predominance purple color At a certain time, this phenomenon coincides with the presence of peaks on the gloss curve. According to this principle, the stars were divided into several groups.
Classic new stars.
Classic new stars differ from the variables of explosive in that their optical outbreaks do not have a repeating nature. The amplitude of the curve of their brilliance is clear, and the rise to the maximum point occurs significantly faster. Usually they reach the maximum shine in a few hours, during this period of time a new star acquires a star magnitude equal to about 12, that is, the light stream increases by 60,000 units.
The slower the process of lifting to the maximum, the less noticeably change in the gloss. The new star is shortly remained in the "Maximum" position, usually this period takes time from several days to several months. Then the brilliance begins to decrease, first quickly, then slower to the usual level. The duration of this phase depends on different circumstances, but its duration is at least several years.
In new classic stars, all these phenomena are accompanied by uncontrolled thermonuclear reactions occurring in the surface layers of white dwarf, it is there "borrowed" hydrogen from the second component of the star. New stars are always double, one of the components is necessarily white dwarf. When the mass of the stars component flows to white dwarf, the hydrogen layer begins to shrink and heated, respectively, the temperature rises, helium is heated. All this happens quickly, dramatically, the result is a flash. The radiating surface increases, the star's shine becomes bright, a splash is fixed on the shine curve.
During the active phase of the outbreak, the new star reaches the maximum shine. The maximum absolute star value is about -6 to -9. The new stars this figure is achieved slower, in variable explosive stars - faster.
New stars exist in other galaxies. But what we observe is only their visible star quantity, it is impossible to determine the absolute, since their exact distance to the Earth is unknown. Although, in principle, you can learn the absolute star magnitude of the new, if it is in the maximum proximity to another new star, the distance to which is known. The maximum absolute value is calculated by the equation:
M \u003d -10.9 + 2.3log (t).
t is the time for which the gloss curve of a new star drops to 3 star magnitude.
Dwarf new stars and repetitive new ones.
The closest relatives of new stars are dwarf new stars, their prototype "u twins". Their optical outbreaks are almost similar to flash of new stars, but there are differences in shine curves: their amplitudes are less. Differences are noted and in the repeatability of outbreaks - in new dwarf stars they happen more or less regularly. On average every time in 120 days, but sometimes in a few years. Optical outbreaks of new lasts from several hours to several days, after which a few weeks shine decreases and finally reaches a regular level.
The existing difference can be explained by various physical mechanisms provoking an optical outbreak. In the "u twins", the outbreaks occur due to a sudden change in the interest ratio of matter on white dwarf - its increase. As a result, there is a huge emission of energy. Observations for dwarf new stars in the eclipse phase, that is, when the white dwarf and the disc surrounding it are closed by the star - the system component, it is precisely indicated that it is white dwarf, or rather, its disk is a light source.
Repeating new stars are among the average between classical new and dwarf new stars. As follows from the name, their optical outbreaks are repeated regularly, which relates them to new dwarf stars, but it happens in several decades. Gloss enhancing during the outbreak is more pronounced and is about 8 star quantities, this feature brings them to classic new stars.
Scattered star clusters.
Scattered star clusters find easy. They are called galactic clusters. We are talking about the formations that include from several tens of up to several thousand stars, most of which are visible to the unarmed eye. Star clusters appear before the observer as a section of the sky, densely dilated by the stars. As a rule, such areas of the concentration of stars are well noticeable in the sky, but it happens, and it is quite rare that the cluster is almost indistinguishable. In order to determine whether the sky of the sky is a star cluster or speech about the stars, just closely located to each other, should study their movement and determine the distance to the Earth. Stars, components of clusters, move in one direction. In addition, if the stars that are not far from each other are located at the same distance from the solar system, they are, of course, are interconnected by the forces of attraction and constitute scattered accumulation.
Classification of star clusters.
The length of these stars varies from 6 to 30 light years, the average length is about twelve light years. Inside the star clusters, the stars are concentrated chaotic, unsystematic. The accumulation does not have a clearly pronounced form. When classifying star clusters, angular dimensions should be taken into account, an approximate total number of stars, the degree of their concentration in the cluster and the difference in the shine.
In 1930, American astronomer Robert Sprumpler proposed to classify clusters in the following parameters. All clusters were divided into four classes on the principle of stars concentration and designated Roman numbers from I to IV. Each of the four classes is divided into three subclasses for uniformity of shine stars. The first subclass includes clusters in which the stars have about one degree of luminosity, to the third - with a significant difference in this regard. Then an American astronomer introduced three more categories of classifications of star clusters by the number of stars included in the accumulation. The first category "P" includes systems in which less than 50 stars. The second "M" is a cluster having from 50 to 100 stars. Third - having more than 100 stars. For example, in accordance with this classification, star cluster designated in the catalog as "i 3P" is a system consisting of less than 50 stars, densely concentrated in the sky and possessing varying degrees gloss.
Uniformity of stars.
All stars belonging to any absenty star cluster have characterlike - Uniformity. This means that they have formed from the same gas cloud and first existence have the same chemical composition. In addition, there is an assumption that they all appeared at one time, that is, have the same age. The differences that exist between them can be explained by different progress of development, and this is determined by the mass of the star since its inception. It is known scientists that major stars have a smaller term of existence on comparison with small stars. Large evolve significantly faster. Basically, scattered star clusters are heavenly systems consisting of relatively young stars. This kind of star clusters is deployed mainly in the spiral branches of the Milky Way. It was these sites that were in the recent past the active zones of stars. Exceptions are clusters NGC 2244, NGC 2264 and NGC6530, their age is equal to several tens of millions of years. This is a short time for stars.
Age and chemical composition.
Stars of scattered star clusters are interconnected by the force of attraction. But due to the fact that this connection is not sufficiently strong, scattered clusters can decay. This happens for a long time. The disbandment process is associated with the influence of the gravity of single stars located near the cluster.
Old stars in the composition of scattered star clusters are practically no. Although there are exceptions. First of all, this refers to major clusters, in which the connection between the stars is much stronger. Accordingly, the age of such systems is greater. Among them can be noted NGC 6791. The composition of this star accumulation includes approximately 10,000 stars, its age is about 10 billion years. The orbits of large star clusters take them on a long period time is far from the plane of the galaxy. Accordingly, they have less opportunities to meet with large molecular clouds, which could lead to the disbandment of star cluster.
Stars of scattered star clusters are similar to the chemical composition with the Sun and other stars of the galactic disk. The difference in chemical composition depends on the distance from the center of the Galaxy. The farther from the center, star cluster is located, the less elements from the metal group it contains. The chemical composition also depends on the age of the star cluster. This applies to single stars.
Ball stars clusters.
Ball star clusters, numbering hundreds of thousands of stars, have very unusual view: They have a spherical form, and the stars are concentrated in them so tightly that even with the help of powerful telescopes it is impossible to distinguish between single objects. There is a strong concentration of stars to the center.
Studies of ball clusters are important in astrophysics in terms of studying the evolution of stars, the process of formation of galaxies, studying the structure of our galaxy and the determination of the age of the universe.
Form of the Milky Way.
Scientists found that the ball accumulations were formed at the initial stage of the formation of our galaxy - the protoglactic gas had a spherical form. During the gravitational interaction until the compression is completed, which led to the formation of the disk, the clots of matter, gas and dust were outside it. It was from them that the balls of star clusters were formed. And they formed before the disk appeared and remained there, where they were formed. They have a spherical structure, halo, around which the plane of the galaxy is located later. That is why ball clusters are deployed symmetrically in Milky Way.
Studying the problem of the location of ball clusters, as well as the measurements of the distance from them to the Sun, allowed to determine their length of our galaxy to the center - it is 30,000 light years.
The balls of the star clusters in the time of origin are very old. Their age is 10-20 billion years. They represent the most important element of the Universe, and, undoubtedly, knowledge of these formations will have considerable assistance in explaining the phenomena of the universe. According to scientists, the age of these star clusters is identical to the age of our galaxy, and since all the galaxies have formed at about the same time, it means that the age of the universe can be determined. For this, the age of ball stars should be added from the appearance of the Universe before the formation of galaxies. Compared with the age of ball stars, it is a very small length of time.
Inside the nuclei of the ball clusters.
For the central regions of this type of clusters, a high degree of stars concentration is characterized, about a thousand times more than in the neighboring zones. Over the past decade, it became possible to consider the kernels of the ball stars, or rather, those celestial objects that are in the very center. It is of great importance in the area of \u200b\u200bstudying the dynamics of the stars included in the core, in terms of obtaining information on the systems of celestial bodies related to attraction forces - star clusters belong to this category, - as well as in terms of studying the interaction between stars of clusters by observing or data processing on the computer.
because of high degree The concentrations of stars occur in the most real collisions, new objects are formed, for example, stars having their own characteristics. Double systems may appear, this happens when the collision of two stars does not lead to their destruction, but mutually grieving due to gravity.
Family of ball stars clusses.
The ball stars of accumulations of our galaxy are inhomogeneous education. There are four dynamic families on the principle of removal from the center of the Galaxy and chemical composition. Some ball clusters have more chemical elements of a group of metals, others - less. The degree of metals depends on the chemical composition of the interstellar medium, from which the celestial objects were formed. Ball clusters with a smaller number of metals are older, they are located in the Galo Galaxy. The larger composition of the metal is characteristic of younger stars, they have formed from the medium already enriched by metals due to outbreaks of supernovae, - to this family include "disk clusters" located on a galactic disk.
In the halo, "star clusters of the inside of halo" and "star clusters of the outer part of halo" are located. There are also "star clusters of the peripheral part of halo", the distance from which to the center of the Galaxy is the largest.
Effect of environment.
Star clusters are studied and divided into families not for the sake of classification as a firm. The classification plays a big role in the study of the effect of the surrounding star clusters of the medium on its evolution. In this case, we are talking about our galaxy.
Undoubtedly, the stars accumulation has a huge influence of the gravitational field of the galaxy disk. The ball stars of clusters move around the Galactic Center in elliptical orbits and periodically crosses the galaxy disk. This happens more than 100 million years.
The gravitational field and tidal protrusions emanating from the galactic plane are so intensively acting on the star cluster, which it gradually begins to decay. Scientists believe that some old stars currently deployed in the galaxy were once part of the ball stars. Now they have already collapsed. It is believed that about 5 star clusters decompose for a billion years. This is an example of the influence of the galactic environment on the dynamic evolution of the ball stars.
Under the action of the gravitational influence of the galactic disk on the star accumulation, a change in the length of the accumulation occurs. We are talking about stars located far from the center of the cluster, on them in more than The force of attraction of a galactic disk, and not the very starry accumulation itself. There is a "evaporation" of the stars, the size of the accumulation is reduced.
Supernovae stars.
Stars are also born, grow and dying. Their end can be slow and gradual or sharp and catastrophic. It is characteristic of the stars of very large sizes that end the existence of an outbreak, these are supernovae stars.
Opening of supernovae stars.
For centuries, the essence of supernovae was unknown by scientists, but observations were carried out from time immemorial. Many supernovae stars are so bright that they can be viewed with a naked eye, and sometimes even during the day. The first mentions of these stars appeared in the ancient chronicles in 185. AD. Subsequently, they were observed regularly and scrupulously fixed all the data. For example, court astronomers of emperors Ancient China Many of the open supernovae many years have registered.
Among them, it should be noted a supernovae that flashed in 1054 AD. In the constellation Taurus. The remainder of this supernova is called "Crab Nebula", due to the characteristic form. Systematic observations of supernova stars Western astronomers began to lead late. Only by the end of the XVI century. There were mentions about them in scientific documents. The first observations of the supernovae forces of European astronomers belong to 1575 and 1604. In 1885, the first supernova star in the Galaxy Andromeda was opened. Made it by Baroness Berta de Primanitskaya.
Since the 20s of the XX century. Thanks to the invention, photoplastin opening supernovae follows one after another. Currently, they are open to thousands. Supernovae requires a large patience and permanent observation of the sky. The star should be not just very bright, its behavior should be unusual and unpredictable. "Hunters" behind supernovae is not so much, just over ten astronomers can boast that more than 20 supernovae opened in their life. Palm Championship in such an interesting classification belongs to Fred Zvika - since 1936 he identified 123 stars.
What is supernovae stars?
Supernovae - suddenly flashing stars. This flash is a catastrophic event, the end of the evolution of stars of large sizes. During outbreaks, radiation power reaches 1051 ERG, which is comparable to the energy emitted throughout his life. Mechanisms causing outbreaks in double and single stars are different.
In the first case, the flash occurs under the condition that the second star in the double system is white dwarf. White dwarfs are relatively small stars, their mass corresponds to the mass of the Sun, at the end " life path»They have the size of the planet. White dwarf interacts with his pair in gravitational plan, he "steals" the substance from its surface layers. The "borrowed" substance is heated, nuclear reactions begin, a flash occurs.
In the second case, the star flashes itself, this happens when there are no more conditions for thermonuclear reactions in its depths. At this stage, gravity prevails, and the star begins to shrink the rapid pace. Due to the sharp heating, uncontrollable nuclear reactions begin to occur in the stars core, the energy is released as a flash, causing the destruction of the star.
After the outbreak, the gas cloud remains, it spreads in space. It is "supernova residues" - what remains from the surface layers of the exploded star. The morphology of supernova residues is different and depends on the conditions in which there is a flash of the star - "agencies", and from its characteristic internal traits. The propagation of the cloud occurs differently in different directions, which is associated with interaction with the interstellar gas, it can significantly change the form of the cloud for thousands of years.
The characteristic of supernovae.
Supernovae is a variation of the eructural variables of the stars. Like all variables, supernovae stars are characterized by a gloss curve and easily recognizable signs. First of all, the supernova is characterized by a rapid increase in shine, it lasts a few days until the maximum reaches, this period is about ten days. Then the brilliance begins to decrease - first unsystematic, then sequentially. Studying the shine curve, you can trace the dynamics of the outbreak and explore its evolution. Part of the gloss curve from the beginning of the rise to the maximum corresponds to the flash outbreak, the subsequent descent means the propagation and cooling of the gas shell.
White dwarfs.
In the Star Zoo, there are a great set of stars, different in size, color and gloss. Among them are especially impressive "dead" stars, their internal structure is significantly different from the structure of ordinary stars. The categories of the dead stars include stars of large sizes, white dwarfs, neutron stars and black holes. Due to the high density of these stars, they are classified as "crisis".
Opening.
Initially, the essence of white dwarfs was a complete riddle, it was known only that they are high density compared to conventional stars.
The first open and studied white dwarf was Sirius B, a couple of Sirius - a very bright star. Applying the third law of Kepler, the astronomers calculated the mass of Sirius B: 0.75-0.95 solar mass. On the other hand, its shine was significantly lower than sunny. The star brilliance is associated with the square of the radius. After analyzing the numbers, the astronomers came to the conclusion that the size of Sirius is small. In 1914, the star spectrum of Sirius B was determined by the temperature. Knowing the temperature and glitter, they calculated the radius - 18,800 kilometers.
First studies.
The result obtained marked the opening of a new class of stars. In 1925, Adams measured the wavelength of some radiation lines in Sirius B spectrum and determined that it was more than supposed. The red displacement fits into the framework of the theory of relativity, a few years before the events of the Einstein open Einstein. Using the theory of relativity, Adams was able to calculate the radius of the star. After opening two more similar to Sirius b stars Arthur Eddington concluded that in the universe there are many such stars.
So, the existence of dwarfs was established, but their nature still remained a mystery. In particular, scientists could not understand how the mass like a sunny can fit in such a small body. Eddington comes to the conclusion that "with such a high density gas loses its properties. Most likely, white dwarfs consist of degenerate gas. "
The essence of white dwarfs.
In August 1926, Enrico Fermi and Paul Dirac developed the theory describing the state of gas under conditions of very high density. Using it, Fowler in the same year found an explanation of the steady structure of white dwarfs. In his opinion, due to the high density, gas in the bowels of white dwarf is in degenerate state, and the gas pressure is almost independent of temperature. The stability of white dwarf is maintained by the fact that the power of the gas is opposed to the pressure of the dwarf. The study of white dwarfs continued Indian physicist Chandrayekar.
In one of his works, published in 1931, he does important opening - the mass of white dwarfs can not exceed a certain limit, it is associated with their chemical composition. This limit is 1.4 of the mass of the Sun and is called the "Canderekar limit" in honor of the scientist.
Almost ton in cm3!
As it follows from the name, white dwarfs are small-sized stars. Even if their mass is equal to the mass of the Sun, they are still in size they look like a planet of the land type. Their radius is approximately 6000 km - 1/100 from the radius of the sun. Considering the mass of white dwarfs and their size, you can make only one conclusion - their density is very high. The cubic centimeter of white dwarfs weighs almost ton on earthly standards.
Such a high density leads to the fact that the stars gravitational field is very strong - approximately 100 times the solar is longer, and with the same mass.
Main characteristics.
Although nuclear reactions no longer occur in the kernel of white dwarfs, its temperature is very high. Heat rushes to the surface of the star, and then distributed in outer space. The stars themselves are slowly cooled until they become invisible. The surface temperature of "young" white dwarfs is about 20,000-30000 degrees. White dwarfs are not only white color, There are yellies. Despite the high surface temperature, due to small size, the luminosity is low, the absolute star value can be 12-16. White dwarfs are cooled very slowly, so we see them in such large quantities. Scientists have the opportunity to study their main characteristics. White dwarfs are included in the Mr. diagram, they occupy a little space under the main sequence.
Neutron stars and pulsars.
The name "Pulsar" comes from the English combination of "Pulsating Star" - "pulsating star". A characteristic feature of the pulsars, in contrast to other stars, is not constant radiation, but regular pulsed radio emission. The impulses are very fast, the duration of one pulse lasts from thousands of seconds of a second to, the most, a few seconds. The shape of the impulse and periods of different pulsars of unequal. Due to the strict periodicity of radio emission, the pulsars can be viewed as cosmic chronometers. Over time, periods decrease to 10-14 s / s. Every second, the period changes by 10-14 seconds, that is, a decrease occurs about 3 million years.
Regular signals.
The history of the opening of the pulsars is quite interesting. The first PSR 1919 + 21 pulsar was recorded in 1967 Belle and Anthony Hewish from the University of Cambridge. Bell, young physicist, conducted research in the field of radio astronomy to confirm the theses put forward by them. Suddenly he discovered a radio signal of moderate intensity in a region close to the galactic plane. The strangeness was that the signal was interrupted - he disappeared and again occurred through regular intervals in 1.377 seconds. It is said that Bell jogging went to his professor to inform him about the opening, but the latter did not give it due attention, believing that it was about radio signal from the ground.
Nevertheless, the signal continued to manifest itself regardless of earthly radioactivity. This indicated that the source of its appearance has not yet been established. As soon as the data on the opening took place was published, numerous assumptions arose that the signals go from the Ghost extraterrestrial civilization. But scientists were able to understand the essence of the pulsars without the help of alien worlds.
The essence of pulsars.
After the first, many more pulsars were opened. Astronomers concluded that these celestial bodies belong to the sources of impulse radiation. The most numerous objects of the universe are the stars, so scientists decided that these celestial bodies are likely to relate to the class of stars.
The rapid movement of the star around its axis is most likely the cause of ripples. Scientists measured periods and tried to determine the essence of these celestial bodies. If the body rotates at a speed greater than some kind of maximum speed, it disintegrates under the influence centrifugal forces. So, there must be a minimum value of the rotation period.
From the calculations carried out, it should be that to rotate the star with a period measured by thousandths of a second, its density should be about 1014 g / cm3, as in atomic nuclei. For clarity, it is possible to bring such an example - imagine a mass equal to Everest, in the volume a piece of sugar.
Neutron stars.
From the thirties, scientists assumed that there is something similar in the sky. Neutron stars are very small, super-delicate celestial bodies. Their mass is about equal to 1.5 masses of the Sun, concentrated within a radius of about 10 km.
Neutron stars consist mainly of neutrons - particles devoid of electrical charge, which together with protons constitute the kernel of the atom. Due to the high temperature in the depths of the star, the substance is ionized, electrons exist separately from the nuclei. With such a high density, all the kernels disintegrate into their neutrons and protons. Neutron stars are the final result of the evolution of a large mass star. After the sources of thermonuclear energy exhaustion in its depths, it explodes sharply as a supernova. External stars of the star are reset into space, a gravitational collapse takes place in the core, a hot neutron star is formed. The collapse process takes the fraction of a second. As a result of the collapse, it begins to rotate very quickly, with periods in thousands of seconds of a second, which is typical for the pulsar.
Razzation radiation.
There are no sources of thermonuclear reactions in the neutron star, i.e. They are inactive. The radiation of ripples is not from the bowels of the stars, but from the outside, from the zones surrounding the surface of the star.
The magnetic field of neutron stars is very strong, in millions of times greater than the magnetic field of the Sun, it stops the space, creating a magnetosphere.
The neutron star emits in the magnetosphere of electrons and positrons, they rotate at a speed close to the speed of light. The magnetic field affects the movement of these elementary particles, they move along the power lines, following the spiral trajectory. Thus, they are released by the kinetic energy in the form of electromagnetic radiation.
The period of rotation increases due to the reduction of rotational energy. At old pulsars, the pulsation period is longer. By the way, not always the pulsation period is strictly periodic. Sometimes he slows down sharply, it is associated with the phenomena wearing the name "Glitches" - this is the result of "microswitters".
BLACK HOLES.
The image of the heavenly arch affects the variety of shapes and colors of the celestial bodies. What is not only in the universe: stars of any colors and sizes, spiral galaxies, nebula of unusual forms and color hammes. But in this "space zoo" there are "copies", exciting special interest. These are even more mysterious celestial bodies, as it is difficult to observe them. In addition, their nature is not fully clarified. Among them, a special place belongs to "black holes".
Motion speed.
In everyday speech, the expression "black hole" means something bottomless, where the thing fails, and no one will ever know what happened to her in the future. What are black holes in reality? To understand this, we will return in history for two centuries ago. In the XVIII century French Mathematics Pierre Simon de Laplace introduced this term for the first time when studying the theory of gravity. As you know, any body having a certain mass is land, for example, has a gravitational field, it attracts the surrounding bodies.
That is why the appreciated top item falls to the ground. If the same subject to quit forward, it will overcome for some time the attraction of the Earth and will fly some distance. The minimum required speed is called "Motion Speed", it is 11 km / s. The speed of movement depends on the density of the celestial body, which creates a gravitational field. The more density, the more should be speed. Accordingly, you can put forward the assumption as two centuries ago Laplace, which in the universe there are bodies with such a high density that the speed of their movement exceeds the speed of light, that is, 300,000 km / s.
In this case, even the light could give in power of attraction of such a body. A similar body could not emit light, and in this regard, it would remain invisible. We can present it as a huge hole, in the picture - black. Undoubtedly, the theory formulated by Laplas, it does not carry a time imprint and seems too simplistic. However, during Laplace, a quantum theory was not yet formulated, and from a conceptual point of view, the consideration of the light as a material body seemed to be nonsense. At the very beginning of the XX century with the appearance and development quantum mechanics It became known that the light in some conditions acts as material radiation.
This provision was developed in the theory of relativity of Albert Einstein, published in 1915, and in the works of German physics Karl Schwarzshild in 1916, he led the mathematical base under the theory of black holes. Light can also be subject to action of attraction force. Two centuries ago Laplas touched a very important problem in terms of physics development as science.
How do black holes appear?
The phenomena we are talking about the name "Black holes" in 1967 due to the American astrophysics John Willer. They are the ultimate result of the evolution of large stars, the mass of which is above five of the solar masses. When all reserves of nuclear fuel are exhausted and the reaction no longer occurs, the death of the star comes. Next, its fate depends on its mass.
If the mass of the star is less than the mass of the Sun, it continues to shrink until it goes out. If the mass is considerable, the stars explode, then we are talking about a supernovae. The star leaves behind the traces, - when a gravitational collapse takes place in the core, the whole mass is going to the ball of compact sizes with a very high density - 10,000 times more than that of the nucleus of the atom.
Relative effects.
For scientists, black holes are a magnificent natural laboratory, which allows experiments on various hypotheses in terms of theoretical physics. According to the theory of Einstein's relativity, the laws of physics affect the local field of attraction. In principle, time flows in different ways next to the gravitational fields of different intensity.
In addition, the black hole affects not only for a while, but also on the surrounding space, affecting its structure. According to the theory of relativity, the presence of a strong gravitational field arising from such a powerful celestial body, like a black hole, distorts the structure of the surrounding space, and its geometrical data is changed. This means that about black hole A short distance connecting two points will not be a straight line, but a curve.
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