Three aggregate states of the substance are known - solid, liquid and gaseous. What will happen to a substance with consistent heating to high temperatures in a closed volume? - Sequential transition from one aggregate state to another: body Body - Liquid Gas (due to an increase in the speed of molecules with the increase in temperature). With further heat heating at temperatures above 1,200 ºС, the decay of gas molecules to atoms begins, and at temperatures above 10,000 ºС - partial or complete decay of gas atoms into the components of their elementary particles - electrons and nuclei of atoms. Plasma is the fourth state of a substance in which molecules or atoms of the substance are partially or completely destroyed under the action of high temperatures or for other reasons. 99.9% of the substance of the Universe is in a state of plasma.
Stars are a class of cosmic bodies with a mass of 10 26 -10 29 kg.
Star is a split plasma spherical cosmic body, as a rule, in hydrodynamic and thermodynamic equilibrium.
If the equilibrium is broken, the star begins to pulsate (its size, luminosity and temperature change). Star becomes a variable star.
Variable star - This is a star that changes the brilliance over time (visible brightness in the sky). The causes of variability may be physical processes in the depths of the star. Such stars are called physical variables (for example, Δ Cepheva. Similar to it, variable stars began to call cepheidami).
Meet I. estimated variables Stars, the cause of the variability of which are mutual eclipses of their components(for example, β Persea - Algole. Her variability first discovered the Italian economist and astronomer Geminian Montanari in 1669).
Stretch-variable stars are always double, those. Consist of two closely arranged stars. Variable stars on star maps are indicated by a circle:
Not always stars - balls. If the star rotates very quickly, then its shape is not a spherical. The star is compressed from the poles and becomes similar to the mandarin or pumpkin (for example, Vega, Regul). If the star is double, then the mutual attraction of these stars to each other also affects their shape. They become egg-shaped or melon (for example, double-star components β lira or spikes):
Stars are the main inhabitants of our galaxy (our galaxy is written with a capital letter). It has about 200 billion stars. With the help of even the biggest telescopes, it is possible to consider only half apler from the total number of galaxy stars. In the stars, more than 95% of the total substance observed in nature are concentrated. The remaining 5% is the interior gas, dust and all non-simulating bodies.
In addition to the Sun, all the stars are from us so far that even in the largest telescopes they are observed in the form of glowing points of different colors and gloss. The nearest to the Sun is the α centaution system, consisting of three stars. One of them is a red dwarf called Proxima - is the closest star. Up to her 4.2 light years. To Sirius - 8.6 sv. years, to Altair - 17 sv. years. Before VEGI - 26 st. years. To the polar star - 830 st. years. Until Deneba - 1,500 sv. years. For the first time, the distance to another star (it was Vega) in 1837 was able to determine V.Ya. Struve.
The first star, who has been able to obtain a disk image (and even some spots on it) - Bethelgeuse (α Orion). But this is because the diameter of Bethelgeuse exceeds the sun 500-800 times (the star pulsates). Altair disk (α α) was also obtained, but this is because Altair is one of the nearest stars.
The color of the stars depends on the temperature of their external layers. Temperature range - from 2,000 to 60,000 ° C. The coldest stars are red, and the hottest is blue. According to the color of the star, it is possible to judge how strongly its external layers are rapid.
Examples of red stars: Antares (α of Scorpion) and Bethelgeuse (α Orion).
Examples of orange stars: Aldebaran (α Taurus),
ArkurTur (α Volopasa)
and Pollux (β twins).
Examples of yellow stars: the sun, the chapel (α of the eating) and Toliman (α centaution).
Examples of yellowish-white stars: a probe (α of small ps) and canopus (α keel).
Examples of white stars: Sirius (α large PSA), Vega (α lira), Altair (α Eagle) and denb (α swan).
Examples of bluish stars: Regul (α lion) and spice (α virgin).
Due to the fact that very little light comes from the stars, the human eye is able to distinguish between the color shades only in the brightest of them. In binoculars and especially in the telescope (they catch more light than the eye) the color of the stars becomes more noticeable.
With depth, the temperature is growing. Even the coldest stars in the center the temperature reaches millions of degrees. At the sun in the center about 15,000,000 ° C (also used Kelvin scales - the scale of absolute temperatures, but when it comes to very high temperatures, a difference of 273 º between Celvin and Celsius scales can be neglected).
What does the star subsoil warms so much? It turns out, there are happening thermonuclear processesAs a result of which a huge amount of energy is distinguished. Translated from the Greek "Thermos" means warm. The main chemical element from which the stars are hydrogen.It is he who is fuel for thermonuclear processes. In these processes, the nuclei of hydrogen atoms into the core of helium atoms is accompanied, which is accompanied by the release of energy. The number of hydrogen nuclei in the star decreases, and the number of helium nuclei increases. Over time, other chemical elements are synthesized in the star. All chemical elements from which there are molecules of various substances, once in the depths of the stars were born. "Stars are the past of a person, and a person is the future of the stars," it is sometimes figuratively spoken.
The process of emitting the star of energy in the form of electromagnetic waves and particles is called radiation. Stars emit energy not only in the form of light and heat, but also other types of radiation - gamma rays, x-ray, ultraviolet, radio emission. In addition, the stars emit threads of neutral and charged particles. These streams form a star wind. Stellar wind - This is the process of the expiration of the substance from the stars in the outer space. As a result, the mass of the stars constantly and gradually decreases. It is the star wind from the Sun (Sunny Wind) leads to the appearance of polar radiances on earth and other planets. It was the solar wind that deflects the tails of comet in the opposite side of the sun.
Stars appear, naturally, not from emptiness (space between stars is not an absolute vacuum). The material serves gas and dust. They are distributed in space unevenly, forming shapeless clouds of very small density and enormous length - from one to two to dozen light years. Such clouds are called diffuse gas-dust nebula. The temperature in them is very low - about -250 ° C. But the stars are formed in each gas-dust nebula. Some nebulae can exist without stars for a long time. What conditions are needed to start the process of nucleation of stars? The first thing is the mass of the clouds. If the matter is not enough, then, of course, the star will not appear. Second, compactness. In too extended and loose cloud, the processes of its compression can begin. Well, and thirdly, the seed is needed - i.e. The bunch of dust and gas, which will then become an embryo of the stars - the protostar. Protocol - This is a star at the final stage of its formation. If these conditions are observed, the gravitational compression and heating of the cloud begins. This process ends star formation - The appearance of new stars. It takes this process millions of years. The astronomers were found in the nebula, in which the star formation process in full swing - some stars have already lit, some are in the form of embryos - protozoases, and the nebula is still preserved. An example is the big nebula of Orion.
The main physical characteristics of the star are the luminosity, mass and radius (or diameter), which are determined from observations. Knowing them, as well as the chemical composition of the star (which is determined by its spectrum), you can calculate the model of the star, i.e. Physical conditions in its depths, explore the processes that occur in it.Let us dwell on the main characteristics of the stars.
Weight. You can directly evaluate the mass only by gravitational stars on the surrounding bodies. The mass of the Sun, for example, was determined by the famous periods of circulation around it planets. Other stars of the planet are not directly observed. Significant measurement of the mass is possible only in double stars (with a generalized Newton III Law of Kepler, Noh and then the error is 20-60%). Approximately half of all stars in our galaxy - double. Mass stars fluctuate from ≈0.08 to ≈100 mass of the sun.Stars with a mass less than 0.08 mass of the Sun does not happen, they simply do not become stars, but remain dark bodies.Stars weighing more than 100 masses of the Sun are extremely rare. Most of the stars have a mass of less than 5 masses of the sun. The fate of the star depends on the mass, i.e. That scenario for which the star is developing, evolving. Small cold red dwarfs are very economical consumed hydrogen and therefore their lives continues hundreds of billions of years. The lifespan of the Sun - Yellow Dwarf - about 10 billion years (the sun has already lived about half of their life). Massive supercrowders consume hydrogen quickly and fade already a few million years after their birth. The more massive star, the shorter its life path.
The age of the universe is estimated at 13.7 billion years. Therefore, stars age more than 13.7 billion years have not yet exist.
- Stars with mass 0,08 Sun masses are brown dwarfs; Their fate is constant compression and cooling with the cessation of all thermonuclear reactions and the transformation into dark planet-like bodies.
- Stars with mass 0,08-0,5
Sun masses (these are always red dwarfs) After the consumption of hydrogen, they begin to slowly shrink, while heating and becoming white dwarf.
- Stars with mass 0,5-8
The masses of the Sun at the end of life turn first in the red giants, and then in white dwarfs. External stars of the star are dissipated in outer space in the form planetary nebula. Planetary nebula often has the shape of the sphere or ring.
- Stars with mass 8-10 The masses of the sun can be exploded at the end of life, and can become calmly, first turning into red superdgigants, and then in red dwarfs.
- Stars with a mass of more 10
The mass of the Sun at the end of the life path is first becoming red supercrutants, then explode like supernovae (a supernova star is not a new one, but an old star) and then turn into neutron stars or become black holes.
Black holes - It is not openings in outer space, but objects (residues of massive stars) with a very large mass and density. Black holes do not have supernatural nor magical forces, are not "monsters of the Universe." They simply have such a strong gravitational field that no radiation (nor the visible light, nor invisible) cannot leave them. Therefore, black holes are not visible. However, they can be detected by their impact on the surrounding stars, nebula. Black holes are a completely ordinary phenomenon in the universe and they should not be scared. In the center of our galaxy, it is possible, there is a supermassive black hole.
Radius (or diameter). Star dimensions vary widely - from several kilometers (neutron stars) to 2,000 diameters of the Sun (supergiant). As a rule, the smaller the star, the higher its average density. In neutron stars, the density reaches 10 13 g / cm 3! Screw such a substance weighed 10 million tons on Earth. But ultra-nucleons have a density less than air density at the surface of the Earth.
Diameters of some stars in comparison with the Sun:
Sirius and Altair 1.7 times more,
Vega 2.5 times more,
Regult is 3.5 times more,
Arcturus is 26 times more
Polar 30 times more
Rigel is 70 times more
Denief 200 times more
Antares 800 times more
YV Big PSA 2,000 times more (the largest star from famous).
The luminosity is the total energy emitted by the object (in this case by the stars) per unit of time. The luminosity of the stars are usually compared with the luminosity of the sun (the luminosity of the stars expressed through the luminosity of the Sun). Sirius, for example, 22 times emits more energy than the sun (Sirius's luminosity is 22 suns). The luminosity of the vegue is 50 suns, and the luminosity of Deneba is 54,000 Suns (Denb is one of the most powerful stars).
Visible brightness (more correct, shine) stars on the earthly sky depends on:
- distances to Star. If the star will approach us, then its visible brightness will gradually increase. And vice versa, when removing the star from us, its visible brightness of little grave will decrease. If you take two identical stars, then close to us will seem more bright.
- from the temperature of the external layers. The stronger the star is riveted, the greater the light energy it sends into space, and the brighter it will seem. If the star cools, then the visible brightness in the sky will decrease. Two stars of the same sizes and at the same distances from us will seem the same by visible brightness, provided that they emit the same amount of light energy, i.e. Have the same temperature of the external layers. If one of the stars is colder than the other, it will seem to be less bright.
- from sizes (diameter). If you take two stars with the same temperature of the external layers (one color) and arrange them at the same distance from us, then a larger star will radiate more light energy, and therefore it will seem brighter in the sky.
- from the absorption of the light by the clouds of cosmic dust and gas on the way of the beam. The thicker layer of cosmic dust, the greater the light from the star it absorbs, and the dull it seems the star. If we take two identical stars and put in front of one of them gas-dust nebula, then this star and will seem less bright.
- from the height of the star over the horizon. There is always a dense haze near the horizon, which absorbs part of the light from the stars. Near the horizon (shortly after sunrise or shortly before the occasion), the stars always look more dull than when they are above the head.
It is very important not to confuse the concepts "seem" and "be".
Star can be very bright in itself, but seem Duffen due to various reasons: due to the long distance to it, due to small sizes, due to the absorption of its light of cosmic dust or dust in the atmosphere of the Earth. Therefore, when they talk about the brightness of the star on the earthly sky, they use phrase "Visible brightness" or "glitter".
As already mentioned, there are double stars. But there are also triple (for example, α centaurus), and quadruple (for example, ε lira), and five, and gear (for example, Castor), etc. Separate stars in a star system called components. Stars with the number of components more than two called multiple Stars. All components of a multiple star are connected by mutual gravity (form the stars system) and move through complex trajectories.
If there are many components, then this is not a multiple star, but star accumulation. Distinguish ball and scattered Star clusters. Ball clusters contain many old stars and are more older than clusters scattered, containing many young stars. Ball clusters are quite stable, because The stars in them are at short distances from each other and the strength of the mutual attraction between them is much more than between the stars of scattered clusters. Scattered clusters over time are scattered even more.
Scattered clusters, as proper, are located on the Milky Way Licap or nearby. On the contrary, ball clusters are located on the Star Sky away from the Milky Way.
Some star clusters can be seen in the sky even with a naked eye. For example, scattered accumulations of giad and pleiades (m 45) in the Taurus, scattered cluster of nursery (M 44) in cancer, ball cluster M 13 in Hercules. Quite a lot of them visible in binoculars.
Experts put forward several theories of their occurrence. The most likely of the bottom states that such stars are blue, very long ago, and they had a merger process. When 2 stars are combined, then a new star with a much large brightness, mass, temperature arises.
Blue Stars Examples:
- Gamma sails;
- Rigel;
- Dzeta Orion;
- Alpha Giraffa;
- Zeta feed;
- Tau of big dog.
White Stars - White Stars
One scientist found a very dim smelly white star, which was a satellite of Sirius and she got the name Sirius V. Surface is a unique star of warming up to 25,000 Kelvinov, but her radius is small.
White stars Examples:
- Altair in the constellation Eagle;
- Vega in the constellation Lyra;
- Castor;
- Sirius.
Yellow Stars - Yellow Stars
Such stars have a yellow glow, and their mass is located within the mass of the Sun - this is about 0.8-1.4. The surface of such stars is usually warmed up to a temperature of 4-6 thousand Kelvinov. Lives such a star about 10 billion years.
Yellow stars Examples:
- Star HD 82943;
- Toliman;
- Dubih;
- Hara;
- Alhita.
Red Stars - Red Stars
The first red stars were opened in 1868. Their temperature is pretty low, and the external layers of the red giants are filled with a large amount of carbon. Earlier, such stars were two spectral classes - N and R, but now scientists were able to determine another general class - C.
With the help of a telescope, you can watch 2 billion stars up to 21 star magnitude. There is a Harvard spectral classification of stars. In it, spectral classes are located in order to reduce the temperature of the stars. Classes are denoted by the letters of the Latin alphabet. Their seven: o - b - a - p - o - k - M.
A good temperature indicator of the outer stars of the star is its color. Hot stars of spectral classes o and in blue color; Stars similar to our Sun (whose spectral class 02) are represented by yellow, the stars of the spectral classes to and m - red.
Brightness and color of stars
All stars are color. Blue, white, yellow, yellowish, orange and red stars distinguish. For example, Bethelgeuse - Red Star, Castor - White, Capella - Yellow. In brightness, they are divided into stars of the 1st, 2nd, ... N-th starry value (N max \u003d 25). To the true size of the term "Star Value" does not have a relationship. Star magnitude characterizes the light stream coming to the ground from the star. Star quantities can be fractional, and negative. Star quantity scale is based on the perception of light by the eye. The separation of stars on star magnitudes by visible brightness was performed by ancient Greek astronomer of hypoches (180-110 years. BC). The brightest stars of Hipparch attributed the first star magnitude; following gloss gradations (i.e., about 2.5 times more weak), he counted the stars of the second star magnitude; stars, weaker than stars of the second star magnitude 2.5 times were named stars of the third star magnitude, etc.; Stars at the limit of appearances with the naked eye was attributed to the sixth star magnitude.
With such a gradation of the brightness of the stars, it turned out that the stars of the sixth star magnitude are weaker than stars of the first stellar value of 2.55 times. Therefore, in 1856, English Astronomer N. K. Potoyy (1829-1891) proposed to be considered the stars of the sixth magnitude those that weaker than the first star magnitude are 100 times. All stars are located at different distances from the ground. It would be easier to compare star values \u200b\u200bif the distances were equal.
The star magnitude that the star would have with a distance of 10 parses, called an absolute star magnitude. The absolute stellar value is indicated - M., and the visible stellar value - m..
The chemical composition of the outer layers of stars, from which their radiation comes, is characterized by a complete predominance of hydrogen. In second place is helium, and the content of the remaining elements is quite small.
Temperature and mass of stars
Knowledge of the spectral class or the color of the star immediately gives the temperature of its surface. Since the stars emit approximately as completely black bodies of the appropriate temperature, the power emitted by the unit of their surface per unit of time is determined from the Stephen's law - Boltzmann.
The division of stars on the basis of a comparison of the luminosity of the starry in the current temperature and color and the absolute star magnitude (Herzshprung-Ressel diagram):
- the main sequence (in the center of it is the sun - Yellow Dwarf)
- supergianta (Great in size and large luminosity: Antares, Bethelgei)
- the sequence of red giants
- dwarfs (White - Sirius)
- subcarliki
- white-blue sequence
This division is also in the age of the star.
Distinguish the following stars:
- ordinary (sun);
- double (Mitsar, Albcor) are divided into:
- a) visa-double, if their duality is seen when observed in the telescope;
- b) multiples are the system of stars with a number more than 2, but less than 10;
- c) optical-double - these are stars that their proximity is the result of a random projection on the sky, and they are far away in space;
- d) physically-double - these are stars that form a single system and apply under the action of the forces of mutual attraction around the general center of the masses;
- e) spectral-double - these are stars that, with mutual treatment, fit close to each other and their duality can be determined but the spectrum;
- e) elaborate-double - these are stars "which when mutual circulation blocked each other;
New stars - These are stars that existed for a long time, but suddenly broke out. Their brightness increased in a short time 10,000 times (the amplitude of the brightness change from 7 to 14 stellar values).
Supernovae - These are stars who were invisible in the sky, but unexpectedly broke out and increased the brightness of 1000 times relative to ordinary new stars.
Pulsar - Neutron star arising from supernova explosion.
Data on the total number of pulsars and their life time indicate that 2-3 pulsars are born in the century, it approximately coincides with the frequency of supernova outbreaks in the galaxy.
Evolution of Star
Like all bodies in nature, the stars do not remain unchanged, they are born, evolved, and finally die. Previously, astronomers believed that millions of years were required to form a star from interstellar gas and dust. But in recent years, photographs of the sky, which is part of the large nebula of Orion, was obtained, where a small accumulation of stars appeared for several years. In the pictures of 1947, a group of three star-like objects was recorded in this place. By 1954, some of them became obliged, and by 1959 these oblong formations broke up on separate stars. For the first time in the history of mankind, people watched the birth of stars literally in front of her eyes.
In many areas of the sky, there are the conditions necessary for the appearance of stars. When studying photographs of foggy sections of the Milky Way, it was possible to detect small black specks of the wrong shape, or globules, which are massive accumulations of dust and gas. These gas-dust clouds contain dust particles, very strongly absorbing light, coming from the stars located behind them. The dimensions globule are huge - up to several light years in the diameter. Despite the fact that the substance in these clusters is very cleared, the total volume is so great that it is enough to form small clusters of stars, by weight of close to the sun.
In the black globule under the action of the radiation pressure emitted by the surrounding stars, compression and sealing of the substance occurs. Such a compression flows for some time depending on the sources of radiation and the intensity of the latter surrounding the globe. Gravitational forces arising from the concentration of mass in the center of the globule, also seek to squeeze the globule, forcing the substance to fall into its center. Falling, particles of the substance acquire kinetic energy and heated the left cloud gasopa.
The fall in the substance can last hundreds of years. Initially, it occurs slowly, leisurely, since gravitational forces, attracting particles to the center, are still very weak. After some time, when the globulus becomes less, and the field is enhanced, the fall begins to occur faster. But the globule is huge, no less than the light year in diameter. This means that the distance from its outer border to the center can exceed 10 trillion kilometers. If the particle from the edge of the globule begins to fall to the center with a speed of little less than 2 km / s, then it will reach only through 200 years of years.
The life expectancy of the star depends on its mass. Stars with a mass of less than the sun, very economically spend the reserves of their nuclear fuel and can shine tens of billions of years. The external layers of stars like our sun, with the masses not large 1.2 masses of the Sun, gradually expand and, in the end, the kernel of the star is completely leaving. At the place of the giant, a small and hot white dwarf remains.
Stars are the most different: small and large, bright and not very, old and young, hot and cold, white, blue, yellow, red, etc.
To understand the classification of stars allows the Herzshprung chart - Russell.
It shows the relationship between the absolute star magnitude, the luminosity, the spectral class and the temperature of the star surface. Stars on this diagram are not accidentally located, but form good distinguishable areas.
Most of the stars are on the so-called the main sequence. The existence of the main sequence is due to the fact that the hydrogen burning step is ~ 90% of the time of the evolution of most stars: the burnout of hydrogen in the central areas of the star leads to the formation of an isothermal helium nucleus, the transition to the stage of the red giant and the care of the star from the main sequence. The relatively brief evolution of red giants leads, depending on their mass, to the formation of white dwarfs, neutron stars or black holes.
Being at various stages of its evolutionary development, the stars are divided into normal stars, the stars of dwarf, the stars of giants.
Normal stars, this is the stars of the main sequence. These include our sun. Sometimes such normal stars like the sun are called yellow dwarfs.
Yellow dwarf
Yellow dwarf - type of small stars of the main sequence having a mass from 0.8 to 1.2 mass of the Sun and surface temperature 5000-6000 K.
The lifetime of yellow dwarf is an average of 10 billion years.
After the whole stock of hydrogen burns, the star increases many times in size and turns into a red giant. An example of this type of stars can be Aldebaran.
The red giant throws out the external gas layers, thereby forming planetary nebula, and the kernel collaps into a small, dense white dwarf.
Red giant is a large star of reddish or orange. The formation of such stars is possible both at the stage of star formation and in the later stages of their existence.
At the early stage, the star radiates due to the gravitational energy highlighted in compression, until the compression is stopped by the beyond thermonuclear reaction.
In the later stages of the evolution of stars, after the burnout of hydrogen in their depths, the stars move from the main sequence and move to the region of the red giants and supergigants of the Herzshprung chart - Russell: this stage lasts about 10% of the time "active" life of stars, that is, the stages of their evolution In the course of which Nucleosynthesi reactions go in star departments.
The star giant has a relatively low surface temperature, about 5000 degrees. A huge radius reaching 800 solar and due to such large sizes is a huge luminosity. The maximum radiation falls on the red and infrared range of the spectrum, because they are called red giants.
The largest giants turn into red supergigants. The star called Bethelgeuse from the Constellation Orion is the brightest example of red supergigant.
The stars of dwarfs are the opposite of giants and can be the following.
White dwarf is what remains of the usual star with a mass that does not exceed 1.4 solar masses, after it passes the stage of the red giant.
Due to the lack of hydrogen, the thermonuclear reaction in the kernel of such stars does not occur.
White dwarfs are very dense. In size, they are not more than land, but they can be compared with the mass of the sun.
This is incredibly hot stars, their temperature reaches 100,000 degrees and more. They shine at the expense of their remaining energy, but over time it ends, and the kernel cools, turning into black dwarf.
Red dwarfs are the most common starry-type objects in the universe. Assessment of their number varies in the range from 70 to 90% of the number of all stars in the galaxy. They are quite different from other stars.
The mass of red dwarfs does not exceed a third of the solar mass (the lower mass limit is 0.08 solar, then brown dwarfs are followed), the surface temperature reaches 3500 K. Red dwarfs have a spectral class M or late K. Stars of this type emit very little light, sometimes in 10,000 times less than the sun.
Given their low radiation, none of the red dwarfs is visible from the ground with a naked eye. Even the closest to the Sun. Red Dwarf proxima Centauri (the closest star in the triple system) and the nearest single red dwarf, barnard star, have an apparent star magnitude of 11.09 and 9.53, respectively. At the same time, the unarmed look can be observed a star with a star magnitude to 7.72.
Due to the low flow rate of hydrogen, red dwarfs have a very greater life expectancy - from tens of billions to tens of trillion years (red dwarf with a mass of 0.1 mass of the Sun will burn 10 trillion years).
In red dwarfs, thermonuclear reactions involving helium are impossible, so they cannot turn into red giants. Over time, they gradually shrink and are increasingly heated until the entire supply of hydrogen fuel is consumed.
Gradually, according to theoretical ideas, they turn into blue dwarfs - the hypothetical class of stars, until one of the red dwarfs have yet managed to turn into a blue dwarf, and then in white dwarfs with a helium core.
Brown dwarf - subsidences (with the masses in the range of approximately 0.01 to 0.08 mass of the Sun, or, respectively, from 12.57 to 80.35 masses of Jupiter and a diameter of approximately equal to the diameter of Jupiter), in the depths of which, in contrast From the stars of the main sequence, the reaction of thermonuclear synthesis is not occurring with the conversion of hydrogen in helium.
The minimum temperature of the stars of the main sequence is about 4000 K, the temperature of brown dwarfs lies between 300 to 3000 K. Brown dwarfs throughout their lives are constantly cooled, with the larger than the dwarf, the slower it cools.
Subcaric dwarfs
Subcaric dwarfs or brown subcarlics are cold formations, by mass underlying the limit of brown dwarfs. Their mass is less than about one cell mass of the Sun or, respectively, 12.57 masses of Jupiter, the lower limit is not defined. They are more commonly considered by the planets, although to the final conclusion about what to consider the planet, and what - by subcaric dwarf, the scientific community has not yet come.
Black Dwarf
Black dwarfs - cooled and as a result, which are not emitted in the visible range of white dwarfs. It is the final stage of the evolution of white dwarfs. The masses of black dwarfs, like the masses of white dwarf, are limited from above 1.4 masses of the sun.
Double Star is two gravitationally related stars, adding around the common center of mass.
Sometimes there are systems from three or more stars, in such a general case the system is called a multiple star.
In cases where such a star system is not too far removed from the ground, the telescope disks separate stars. If the distance is significant, then it is possible to understand that the double star is manifested before the astronomers only on indirect signs - gloss fluctuations caused by periodic eclipses of one star with another and some others.
New star
Stars whose luminosity suddenly increases 10,000 times. The new star is a double system consisting of white dwarf and companion stars located on the main sequence. In such systems, gas from the star gradually flows onto white dwarf and periodically explodes there, causing an outbreak of luminosity.
Supernova
The supernova star is a star that ends up its evolution in a catastrophic explosive process. The flash can be several orders of magnitude more than in the case of a new star. Such a powerful explosion is a consequence of the processes occurring in the star at the last stage of evolution.
Neutron Star
Neutron stars (NZ) are star formations with the masses of about 1.5 solar and dimensions, noticeably smaller than white dwarfs, the typical radius of the neutron star is, presumably, about 10-20 kilometers.
They consist mainly of neutral subatomatic particles - neutrons, tightly compressed gravitational forces. The density of such stars is extremely high, it is commensurate, and according to some estimates, it can several times to exceed the average density of the atomic nucleus. One cubic centimeter of substance NZ will weigh hundreds of millions of tons. The force of gravity on the surface of the neutron star is about 100 billion times higher than on Earth.
In our galaxy, according to scientists' estimates, there may be from 100 million to 1 billion neutron stars, that is, somewhere on one to one thousand ordinary stars.
Pulsary
Pulsary - Space sources of electromagnetic emissions coming to the ground in the form of periodic bursts (pulses).
According to the dominant astrophysical model, the pulsars are rotating neutron stars with a magnetic field, which is tilted to the axis of rotation. When the Earth enters the cone formed by this radiation, then the radiation pulse can be fixed, repeating through the time intervals equal to the period of the stars. Some neutron stars make up to 600 revolutions per second.
Cefeida
Cefeida - class of pulsating stars with a fairly accurate dependence of the luminosity, named after the star Delta Cefhea. One of the most famous cefeid is a polar star.
The above list of the main types (types) of stars with their brief characteristic, of course, does not exhaust the entire possible manifold of stars in the universe.
We never think that it is possible to have some kind of life except our planet, except for our solar system. Perhaps some of the planets rotating around blue or white or red, and maybe a yellow star has a life. Perhaps there is another same planet the Earth on which the same people live, but we still do not know anything about it. Our companions, telescopes found a series of planets, which may have a life, but dozens of thousands of thousands and even millions of light years.
Blue Stars Retained - Blue Stars
Stars that are in the stellar columns of the ball type, the temperature in which above the temperatures of ordinary stars, and for the spectrum is characterized by a significant shift to the blue area than the stars of the accumulation with similar luminosity, the blue stars have been named. This feature allows them to stand out relative to other stars of this accumulation on the Herzshprung-Russell diagram. The existence of such stars refutes all the theories of the evolution of stars, the essence of which is that for stars that arose in the same period of time, it is planned to be placed in a clearly defined area of \u200b\u200bthe Herzshprung-Russell diagram. At the same time, the only factor that affects the exact location of the star is its initial mass. The frequent appearance of the blue retired stars beyond the limits of the aforementioned curve may be a confirmation of the existence of such a concept as an abnormal star evolution. 
Experts trying to explain the nature of their occurrence have nominated several theories. The most likely of them indicates that the data of the blue color stars in the past were double, after which they began to occur or the merge process now began. The result of the fusion of two stars becomes the emergence of a new star having a much larger mass, brightness and temperature than stars of the same age.
If the loyalty of this theory is able to somehow prove, the theory of star evolution would lose their problems in the form of blue retired. As part of the resulting star, there would be a larger amount of hydrogen, which would lead himself similar to the young star. There are facts confirming such theory. Observations have shown that most often the stars are most often found in the central regions of ball clusters. As a result of the number of stars of a single volume prevailing there, close passages or collisions become more likely.
To verify this hypothesis, it is necessary to study the ripple of blue retired, because There may be some differences between the astrosheyshemical properties of the sprawling stars and normally pulsating variables. It is worth noting that it is difficult to measure pulsations. This process also negatively overcrowding the starry sky, small oscillations of pulsations of blue retired, as well as the rarity of their variables.
One of the examples of the merger could be observed in August 2008, then such an incident touched the object V1309, whose brightness increased several tens of thousands of times, and after several months, returned to the initial meaning. As a result of 6-year observations, scientists came to the conclusion that this object is two stars, the period of circulation of which each friend is 1.4 days. These facts pushed scientists to the idea that in August 2008 there was a merger process of these two stars.
For blue retarded characteristic is the high rotational moment. For example, the speed of rotation of the star, which is located in the middle of the cluster 47 of the Tukanan, is 75 times the speed of rotation of the sun. According to the hypothesis, their mass is 2-3 times higher than the mass of other stars, which are located in the cluster. Also, with the help of research, it was found that if the blue-color stars are close to any other stars, then the latter will have the percentage of oxygen and carbon lower than that of the neighbors. Presumably, the stars are pulling these substances from others moving along their orbit, resulting in their brightness and temperature. The "reserved" stars are found places where the process of turning the initial carbon in other elements occurred.
Blue Star Names - Examples
Rigel, Gamma Sails, Alpha Giraffe, Zeta Orion, Tau of Big PSA, Jet Cide
White Stars - White Stars
Friedrich Bessel, who led the Koenigsberg Observatory, in 1844 an interesting discovery was made. The scientist noticed the slightest deviation of the brightest star of the sky - Sirius, from his trajectory in the sky. Astronomer suggested the presence of a sirium in Sirius, and also calculated the approximate period of the stars around their center of the masses, which amounted to about fifty years. Bessel did not find due support from other scientists, because Satellite no one could detect, although by its mass he had to be comparable to Sirius.
And after 18 years, Alvan Graham Clark, who was engaged in testing the best telescope of those times, a dull white star was discovered next to Sirius, which turned out to be his companion who called Sirius V.
The surface of this star is white is warm up to 25 thousand Kelvinov, and its small radius. Given this, scientists concluded that the high density of the satellite (at the level of 106 g / cm 3 3, while the density of the sirium itself is approximately 0.25 g / cm 3, and the Sun is 1.4 g / cm 3). After 55 years (in 1917), another White Dwarf was opened, called in honor of the scientist who found him - the star Wang Mansen, which is in the constellation of fish.
White Star Names - Examples
Vega in the constellation Lyra, Altair in the constellation of the Eagle, (visible in summer and autumn), Sirius, Castor.
Yellow stars - yellow stars
Yellow dwarfs are customary to call small stars of the main sequence, the mass of which is within the mass of the sun (0.8-1.4). If you judge by the name, then such stars have a yellow glow, which is allocated during the implementation of the thermalide process of synthesis of hydrogen helium.
The surface of such stars is heated to a temperature of 5-6 thousand Kelvinov, and their spectral classes are in the range between G0V and G9V. Yellow dwarf lives about 10 billion years old. The combustion of hydrogen in the star becomes the cause of its multiple increase in size and transformation into the red giant. One example of the Red Giant is Aldebaran. Such stars can form planetary nebula, getting rid of the outer layers of gas. In this case, the transformation of the kernel in white dwarf, which has a large density.
If you take into account the Herzshprung-Russell diagram, then yellow stars are in the central part of the main sequence. Since the sun can be called typical yellow dwarf, its model is quite suitable for consideration by the general model of yellow dwarfs. But there are other characteristic yellow stars in the sky, whose names are Alhita, Dhabih, Toliman, Hara, etc. Star data do not have high brightness. For example, the same Toliman, which, if not to take into account the proxy centaur, is closer to the Sun, it has a 0th value, but at the same time its brightness is the highest among all yellow dwarfs. This star is located in the Centauro Constellation, it is also the link of a complex system, which consists of 6 stars. The spectral class of Toliman - G. But Dubih, located in 350 light years from us relates to the spectral class F. But its high brightness is due to the presence of a number of stars belonging to the spectral class - A0.
In addition to Toliman, the spectral class G has HD82943, which is located on the main sequence. This star, due to the chemical composition and temperature similar to the Sun, also has two large-sized planets. However, the form of data orbits of the planets is far from circular, so relatively often occur their rapprochement with HD82943. Currently, astronomers were able to prove that earlier this star had a much larger number of planets, but over time she was completely absorbed.
Yellow Star Names - Examples
Toliman, Star HD 82943, Hara, Dhai, Alhita
Red Stars - Red Stars
If you at least once in your life I have been able to see in the lens of your telescope Red stars in the sky that burned on a black background, then the memory of this moment will help more clearly imagine what it will be written in this article. If you never seemed to have similar stars, next time, be sure to find them. 
If you take a list of the most bright red stars of the sky, which can be easily found even with the help of an amateur telescope, then you can find that they are all carbon. The first red stars were open back in 1868. The temperature of such red giants is low, in addition, their external layers are filled with a huge amount of carbon. If previously similar stars accounted for two spectral classes - R and N, now scientists have identified them into one common class - C. Each spectral class exists subclasses - from 9 to 0. In this case, C0 class indicates that the star has a larger temperature, but Less red than Stars class C9. It is also important that all the stars are in the composition of the carbon prevailing, inherently variables: long-period, half-way or incorrect.
In addition, two stars called in red semi-butter variables were also included in such a list, the most famous of which is M Cief. Its unusual red was interested in William Herschel, who dubbed her "garnet". For such stars, an incorrect change in the luminosity, which can last from a pair of tens to several hundred days of day. Such variable stars refer to the class M (the stars are cold, the surface temperature is from 2400 to 3800 K).
Given the fact that all stars from the rating are variables, it is necessary to make a certain clarity in the notation. It is generally accepted that the red stars are called, which consists of two components - the letters of the Latin alphabet and the name of the constellation of the variable (for example, t hail). The first variable, which was discovered in this constellation, is assigned the letter R and so on, to the letter Z. if there are many such variables, the double combination of Latin letters is provided for them - from RR to Zz. This method allows you to "call" 334 objects. In addition, you can designate the stars and with the letter V in conjunction with the sequence number (V228 swan). The first rating column is assigned to the designation of variables.
The two following columns in the table indicate the location of stars in the period 2000.0 year. As a result of the increased popularity of the Atlas "Uranometria 2000.0" among astronomy lovers, the last rating column displays the search card number for each star that is in the ranking. In this case, the first digit is the display of the volume number, and the second is the sequence number of the card.
Also in the ranking displays the maximum and minimum gloss values \u200b\u200bof star values. It is worth remembering that the large saturation of the red color is observed from the stars whose brightness is minimal. For stars, the variability of which is known, it is displayed as the number of days, but the objects that do not have the right period are displayed as IRR.
To find a carbon star, you don't need a big skill, enough to have the capabilities of your telescope to see it. Even if its size is small, its brightly pronounced red should attract your attention. Therefore, it is not necessary to get upset if it is impossible to immediately detect them. It is enough to take advantage of the atlas to find a short-range star, and then, move from it to red.
Different observers see carbon stars differently. Some of them resemble rubies or burning in the distance of the corner. Others are seen in such stars raspberry or blood-red shades. To start in the ranking there is a list of six brightest red stars, finding and which, you can enjoy the beauty to enjoy their beauty.
Names of red stars - examples
Differences of Stars in Color
There is a huge variety of stars with indescribable color shades. As a result, even one constellation received the name "Jewelry Jewelry Box", the basis of which is blue and sapphire stars, and in his center there is a bright luminous orange star. If we consider the sun, it has a pale yellow color.
Direct factor affecting the difference in color stars is the temperature of their surface. This is simply explained. Light by nature is radiation in the form of waves. The wavelength is the distance between its crests, is very small. To imagine her, you need to share 1cm per 100 thousand identical parts. Several such particles and will be the wavelength of light.
Given that this number is quite small, each, even the most insignificant, its change will be the reason why the picture observed by us will change. After all, our vision is a different length of light waves perceives as different colors. For example, blue color have waves, the length of which is 1.5 times less than that of red.
Also, almost each of us knows that the temperature can have the most direct effect on the color of the tel. For example, you can take any metal object and put it on fire. During heating, it will become red. If the temperature of the fire increased significantly, the color of the subject would change - with red to orange, with orange on yellow, with yellow on white, and finally, with white on blue-white.
Since the sun has surface temperature in the region of 5.5 thousand 0 s, then it is a characteristic example of yellow stars. But the most hot blue stars can warm up to 33 thousand degrees.
Color and temperatures were associated with scientists with physical laws. The body temperature is directly proportional to its radiation and inversely proportional to the wavelength. Blue waves have shorter wavelengths in comparison with red. The hot gases emit photons whose energy is directly proportional to the temperature and inversely proportional to the wavelength. That is why for the hottest stars characteristic is a blue-blue radiation range.
Since nuclear fuel on the stars is not limitless, it has a property to be consumed, which leads to the cooler of stars. Therefore, middle-aged stars have a yellow color, and the old stars we see red.
As a result of the fact that the sun is very close to our planet, it is possible to describe its color with accuracy. But for stars that are in a million light years from us, the task is complicated. It is for this that the device called the spectrograph is used. Throughout it, scientists skip the light emitted by the stars, as a result of which you can spectally analyze almost any star.
In addition, with the help of a star color, you can determine its age, because Mathematical formulas allow you to use spectral analysis to determine the temperature of the star, which is easy to calculate its age.
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