Message on the topic of the physical nature of stars. Abstract: Evolution and the structure of the Galaxy

People can see about the naked eye

6 thousand stars.

Stars are different by:

Building

Most

Temperature (color)

Age

Size

Lamps

Mass stars

It is possible to reliably determine the lot of stars, only if it is a component of a double star. In this case, the mass can be calculated using a generalized third law of Kepler. But even at the same time, the estimate of the error ranges from 20% to 60% and largely depends on the error of determining the distance to the star. In all other cases, it is necessary to determine the mass indirectly, for example, from the dependence of the mass - the luminosity

Color and temperatures

It is easy to see that the stars have different colors - one white, other yellow, third red, etc. White color has, for example, Sirius and Vega, Yellow - Chapel, Red - Bethelgeuse and Antares. Stars of various colors have different spectra and different temperatures. Like an inflamed piece of iron, white stars are hotter, and red - less.

Arctur.

Rigel

Antares

The luminosity of stars

Stars, like the sun, emit energy in the range of all wavelengths of electromagnetic oscillations. You know that the luminosity (L) characterizes the overall power of the star radiation and represents one of its most important characteristics. The luminosity is proportional to the surface area (photospheres) of the star (or the square of the radius R) and the fourth degree effective temperature of the photospheric (T), i.e.

L \u003d 4. π R 2. about T 4.

Isaac Newton (1643-1727) in 1665 Descended the light into the spectrum and explained to his nature. William Vollaston In 1802 Watched dark lines in the sunny spectrum, and in 1814. They independently discovered and described in detail Josef von Fraungofer (1787-1826). 754 lines are isolated in a sunny spectrum.

Distribution of colors in the spectrum \u003d o b a f g k m = You can remember, for example, in the text:

One shaved British dates chewing like carrots.

from 380 to 470 nm have purple and blue color.
from 470 to 500 nm - blue-green.
from 500 to 560 nm - green.
from 560 to 590 nm - yellow-orange.
from 590 to 760 nm - red.

Suchgiangs
Giants
Dwarlia

– this stars B. hundreds once more than our sun.

Bethelgei Star (Orion) exceeds the sun radius 400 times.

Located in the constellation Orion,

exceeds the sun radius 400 times.

– ten times more sun

Regul (Lion), Aldebaran (Taurus) - 36 times more than the sun.

– these are stars in size as our sun or less

White dwarf leyten.
Star Wolf 457.

Star variables change their shine.
There are also double - two closely located stars associated with mutual attraction.

This star is in the constellation of large dogs
Sirius can be observed from any region of the Earth, with the exception of its northern regions.
Sirius is removed by 8,6 light years from the solar system and is one of the nearest stars close to us.

Physical nature of the Sun.

The sun is the central body of our planetary system and the star closest to us.

The average distance of the Sun from the Earth is 149.6 * 10 6 km, Its diameter is 109 times more terrestrial, and the volume of 1300,000 times more than the volume of land. Since the mass of the sun is 1.98 * 10 33 g. (333000 masses of the Earth), then in accordance with its volume we find that the average density of the solar substance is equal to 1.41 g / cm 3 (0.26 medium density of the Earth). According to the known values \u200b\u200bof the radius and mass of the Sun, it is possible to determine that the acceleration of gravity on its surface reaches 274 m / s 2, or 28 times more than the acceleration of gravity to the surface of the Earth.

The sun rotates around the axis against the course of the clockwise when observed from the North Pole of the Ecliptic, that is, in the same direction, in which all the planets appear around it. If you look at the drive of the Sun, then its rotation is made from the eastern edge of the disk to the Western. The axis of rotation of the sun is inclined to the plane of the ecliptic at an angle of 83 °. But the sun rotates not as a solid body. Sideric period of rotation of its equatorial zone is 25 sUT, located 60 ° Heliographic (counted from the solar equator) latitude it is 30 sUT, and the poles reaches 35 sUT.

When observing the sun in the telescope, it is noticeable to weaken its brightness to the edges of the disk, as the rays coming from the deepest and hot parts of the sun pass through the center of the disk.

The layer lying on the transparency of the substance of the Sun substance and emitting visible radiation is called a photosphere. The photosphere is not evenly bright, but discovers the grainy structure. Light grains covering the photoosphere are called granules. Granules - unstable education, the duration of their existence - about 2-3 min And the dimensions range from 700 to 1400 kM . On the surface of the photoosphere, dark spots and light areas called torch are distinguished. Watching stains and torches made it possible to establish the nature of the rotation of the Sun and determine its period.

Above the surface of the photosphere is a solar atmosphere. Its bottom layer has a thickness of about 600 km. The substance of this layer selectively absorbs the light waves of such, the lengths that it can radiate itself. When re-release, the energy scattering occurs, which is the immediate cause of the appearance of the main dark phraungoferon lines in the Sun spectrum.

The following layer of the solar atmosphere - chromosphere has a bright red color and is observed with complete solar eclipses in the form of a scarlet ring, covering the dark disk of the moon. The upper boundary of the chromosphere is constantly worried, and therefore it is the thickness of it oscillate from 15,000 to 20,000 km.

Printuberans are thrown from the chromosphere - fountains of hot gases visible to the naked eye during full solar eclipses. At a speed of 250-500 km / s They rise from the surface of the sun at the distance equal to the average 200000 kM, A. Some of them reach a height of 1500,000 km.

Over the chromosphere is a solar crown, visible with complete solar eclipses in the form of a silver-pearl halo surrounding the sun.

The solar crown is divided into inner and external. The inner crown extends to a height of about 500,000 kM and consists of a rarefied plasma - mixtures of ions and free electrons. The color of the inner crown is similar to the solar, and the radiation is the light of the photosphere, dispelled free electron. The spectrum of the inner crown differs from the solar spectrum by the fact that it does not observe the dark absorption lines, but it is observed against the background of a continuous spectrum of the radiation line, the brightest of which belongs to repeatedly ionized iron, nickel and some other elements. Since the plasma is extremely resolved, the speed of movement of free electrons (and accordingly their kinetic energy) is so large that the temperature of the inner crown is estimated at about 1 million degrees.

The outer crown extends to a height of more than 2 million. km. It consists of the smallest solid particles that reflect the sunlight and give it a light yellow shade.

In recent years, it was found that the solar crown extends much further than previously expected. The most remote parts of the solar crown - superbroke - extend beyond the limits of the earth's orbit. As the sunsser removed from the sun, the temperature of the supercourse gradually decreases, and at the distance of the earth is approximately 200,000 °

The superbone consists of separate sparse electronic clouds, "frozen" into the magnetic field of the Sun, which are moving from high speeds and reaching the upper layers of the earth's atmosphere, ionize and heat it, thereby influencing the climatic processes.

The interplanetary space in the plane of the ecliptic contains fine dust producing the phenomenon of zodiacal light. This phenomenon is that in the spring after sunset in the West or in the fall before the sunrise in the east, there is a weak shine, which protrudes from the horizon in the form of a cone.

Sun spectrum is a absorption spectrum. Against the background of a continuous bright spectrum, numerous dark (fraun-roof) lines are located. They occur during the passage of the beam of light emitted by hot gas through a colder medium formed by the same gas. At the same time, a dark line of its absorption is observed on the spot of the bright line of gas radiation.

Each chemical element has a string range inherent in it, so according to the type of spectrum, the chemical composition of the glowing body can be determined. If the radiating light substance is a chemical compound, then the bands of molecules and their connections are visible in its spectrum. Determining the wavelengths of all spectrum lines, the chemical elements that form the radiating substance can be installed. The intensity of spectral lines of individual elements are judged by the number of atoms belonging to them. Therefore, the spectral analysis allows us to study not only high-quality, but also the quantitative composition of the heavenly luminaries (more precisely, their atmospheres) and is the most important method of astrophysical studies.

About 70 well-known chemical elements are found on the sun. But mostly the Sun consists of two elements:

hydrogen (about 70% by weight) and helium (about 30%). From other chemical elements (only 3%), nitrogen, carbon, oxygen, iron, magnesium, silicon, calcium and sodium have the greatest distribution. Some chemical elements, such as chlorine and bromine, have not yet been detected in the sun. In the spectrum of solar spots, the absorption bands of chemical compounds are also found: cyan (CN), titanium oxide, hydroxyl (OH), hydrocarbon (CH), etc.

The sun is a grandiose source of energy, continuously scattering light and heat in all directions. About 1: 20000,000,000 all energy emitted by the sun is arrived. The amount of energy obtained by the earth from the Sun is determined by the value of the solar constant. Solar constant called the amount of energy obtained per minute 1 cM 2. The surface located on the border of the earth's atmosphere perpendicular to the sunshine. In thermal energy measures, solar constant is 2 cal / cm 2 * min, And in the system of mechanical units, it is expressed by the number of 1.4-10 6 erg / s cm 2.

The temperature of the photosphere is close to 6000 ° C.On radiates energy almost as an absolutely black body, so the effective temperature of the solar surface can be determined using the Stephen-Boltzmann law:

where E - The amount of energy in Erghah emitted in 1 sec. 1 cM 2. solar surface; S \u003d 5.73 10 -5 erg / sec * hail ^4 cm 2 - constant, installed from experience, and T - Absolute temperature in degrees Kelvin.

The amount of energy passing through the surface of the ball described by the radius in 1 but. e. (150 10" cm), equally e. =4*10 33 erg / s * cm 2. This energy is radiated by the entire surface of the Sun, therefore, separating its value to the area of \u200b\u200bthe solar surface, you can determine the value E. and calculate the temperature of the sun surface. It turns out E \u003d 5800 ° C.

There are other methods for determining the surface temperature of the Sun surface, but they all differ from the results of their use, as the sun radiates not quite like an absolutely black body.

It is impossible to directly define the temperature of the internal parts of the Sun, but as it approaches its center, it must increase quickly. The temperature in the center of the Sun is calculated theoretically from the equilibrium condition and the equality of the parish and the consumption of energy at each point of the sun volume. According to modern data, it reaches 13 million degrees.

At temperature conditions that occur in the sun, all its substance is in a gaseous state. Since the sun is in thermal equilibrium, then at each it point should be compensated for the strength of gravity, directed to the center, and the forces of gas and light pressures directed from the center.

High temperature and large pressure in the depths of the Sun determine the multiple ionization of the atoms of the substance and its significant density probably exceeds 100 g / cm 3, Although under these conditions the substance of the Sun retains the properties of the gas. Numerous data lead to the conclusion that for many millions of years the temperature of the Sun remains unchanged, despite the high energy consumption caused by the radiation of the Sun.

The main source of solar energy is the nuclear reaction. One of the most likely nuclear reactions, called proton proton, is to transform four hydrogen nuclei (protons) in the helium core. With nuclear transformations, a large amount of energy is released, which penetrates the solar surface and is emitted to world space.

The radiation energy can be calculated according to the well-known Einstein formula: E. = tC 2, Where E - energy; t - Mass and C is the speed of light in emptiness. The mass of the hydrogen core is 1.008 (atomic units of mass), therefore the mass of 4 protons is 4 1,008 \u003d 4,032 but. eat. Mass formed Kernel helium is 4.004 but. eat. Reducing hydrogen weight by value of 0.028 but. eat. (This is 5 * 10 -26 g) leads to the release of energy equal to:

The total power of the radiation of the Sun is 5 * 10 23 liters. from. Due to radiation, the Sun loses 4 million. t. Substances per second.

The sun is also a source of radiation radiation. The total power of the Sun radio emission in the wave ranges from 8 mM. up to 15 m. Nearby. Such radio emission of the "calm" sun comes from the chromosphere and the crown and is thermal radiation. When the sun appear in a large number of spots, torches and protuberans, the power of radio emission increases thousands of times. Especially large bursts of the radio empty of the "indignant" of the Sun occur during periods of strong outbreaks in its chromosphere.

Spectral classification and physical nature of stars

A variety of and important information about the physical nature of stars, which has modern astronomy, were obtained by the results of the study of the light emitted. The study of the nature of light is carried out by methods of photometry and spectral analysis.

In the middle of the XIX century, the French philosopher-idealist Auguste Cont argued that the chemical composition of the heavenly luminaire will remain forever unknown for science. However, soon the chemical elements known on Earth were opened by the methods of spectral analysis in the sun and stars.

Nowadays, the study of spectra allowed not only to establish the chemical composition of stars, but also measure their temperature, luminosity, diameters, masses, density, rotation speeds and translational movements, as well as determine the distances to those distant stars, the trigonometric parallaxes of which are alive of them inaccessible For measurements.

The physical nature of stars is very different, and therefore their spectra are distinguished by a large variety. Stars, like the Sun, have continuous spectra crossed by dark absorption lines, and this proves that each star is a hot gas body, which gives a continuous spectrum and surrounded by a colder atmosphere.

The star spectra lines are identified with the lines of the chemical elements known on Earth, which serves as evidence of the material unity of the universe. All stars consist of the same chemical elements, mainly from hydrogen and helium.

The cause of a large difference in the star spectra is determined not so much by the difference in the chemical composition of stars, how many different degrees of ionization of the substance of the stellar atmospheres determined mainly temperatures. The modern classification of the star spectra, created at the Harvard Observatory (USA), based on the results of the study of more than 200,000 stars, is based on identifying the belonging of the absorption lines to known chemical elements and the assessment of their relative intensity.

With all the diversity of the stellar spectra, they can be combined into a small number of classes containing similar signs and gradually passing one to another to form a continuous series. The main classes of Harvard classification are indicated by the letters of the Latin alphabet O, In, and F. , G. , K, m, forming a row corresponding to a decrease in the temperatures of stars. To detail the spectral indicators in each class, decimal units denoted by numbers were introduced. Designation A0 corresponds to a typical range of class BUT; A5 means spectrum, medium between classes BUT and F. ; A9 - Spectrum, much closer to F0 , than to a0.

The table shows the characteristics of the spectra corresponding to them temperature and typical stars for each of the spectral classes.

Spectral class	Characteristics of the absorption spectrum	Temperature surface	Typical stars
0	Ionized helium lines,	35 000 °	TO Orpona
(blue stars)	nitrogen, oxygen and silicon
IN	Helium and hydrogen lines	25000 °	Spika
(YULUBOVATO-BASS
stars)
BUT	Hydrogen lines have poppy	10000 °	Siriches
(White stars)	symal intensity. For
mound ionized lines
calcium. Weak appear
metal absorption lines
R	Hydrogen lines weaken.	7500 °	Percent: O.
(yellowish stars)	Intensive lines neutral
and ionized calcium.
Metal lines gradually
strengthen
0	Hydrogen lines even more	6000 °	Suns
(Yellow stars)	weaken. Numerous
metal absorption lines
TO	Metal lines are very inten	4500 °	ART-U-R
(Orange Stars)	sivna. Intensive carbon strip
hydrogen CH. Weak lines
absorption Oxide Titan Tyug
M.	Lines of neutral metals	3500 °	BETEL.-
(Red Stars)	very strong. Intensive in	heise
molecular absorption leases
connections

In addition to the main spectral classes, there are additional classes R , N, S Little stars whose temperature is below 3000 °.

The temperatures given in the table belong to the surface layers of stars, in the depths of them dominate temperatures of about 10-30 million degrees. High temperature ensures the flow of spontaneous nuclear reactions, i.e. the processes discussed earlier.

Star color depends on its temperature. Cold stars emit predominantly in long waves corresponding to the red part of the spectrum, and hot-in short waves represented by a purple part of the spectrum.

Human eye is most susceptible to yellow-green rays, and The usual photographic plate is to the blue and purple rays of the spectrum. As a result, when observing the stars visual and photographic methods, various star values \u200b\u200bare obtained for the same star.

In astronomy, the color is measured by comparing the magnitudes of the stars, specific visual and photographs, and evaluate it with a color indicator, which is the difference in photographic and visual stars:

Conventionally believe that for the stars of the spectral class BUT 0 Color Indicator is a bullet. The figure of the color of coarse stars is positive, since they are intensively emitted in long waves to which the most sensitive eyes. An indicator of the color of hot stars is a negative value, since their radiation is most advantageous, and the photoflax is most susceptible to blue and purple rays.

The dependences between the color indicators and the spectra of stars are set empirically. Make up the table, from which the star color indicator approximately determines its spectral class.

The main factors determining the amount of emitted energy are the temperature and the area of \u200b\u200bthe radiating surface of the star. The study of the guidelines of stars led to the division of them into two characteristic groups: stars-giants and stars-dwarfs. Stars giants have high luminosity and a large radiation area (large volume), but have a small density of the substance. Stars-dwarfs are characterized by low luminosity, low volume and significant density of the substance.

The difference between giants and dwarfs is most dramatically manifested in the stars of the spectral classes M. and TO, In which the difference in luminosity reaches 9 m_ 10 m, that is, the red giants of 5-10 thousand times brighter red dwarfs. In yellowish and yellow stars of classes F and G, along with giants and dwarfs, the stars of intermediate luminations are also numerous.

For the characteristics of the luminosities of the stars in front of the capital letter of their spectral class, small letters are additionally written: G - for the giants and D stars - for stars-dwarfs. Capella GG0 - Gigant Class G0, Sun DG 3 - Dwarf class G. 3 etc.

Modern ideas about the emergence and evolution of stars

Section of astronomy, in which the issues of origin and the development of celestial bodies are studied, called cosmogony. Cosmogonia explores the processes of changing the forms of cosmic matter, leading to the formation of individual celestial bodies and their systems, and the direction of their subsequent evolution. Cosmogonical studies also lead to solving such problems as the occurrence of chemical elements and cosmic rays, the appearance of magnetic fields and sources of radio emission.

The solution of cosmogonic problems is associated with great difficulties, since the emergence and development of celestial bodies occurs so slowly, which is impossible to trace these processes by direct observations; The timing of the flow of space events is so great that the entire history of astronomy in comparison with their duration seems to be a moment. Therefore, cosmogonia from the comparison of the simultaneously observed physical properties of heavenly bodies establishes the characteristic features of consecutive stages of their development.

Insufficiency of actual data leads to the need to issue the results of cosmogonical studies in the form of hypotheses, i.e. scientific assumptions based on observations, theoretical calculations and basic laws of nature. Further development of the hypothesis shows to which extent it complies with the laws of nature and the quantitative assessment of the facts predicted.

Conditions of cosmogony, leading to the approval of the material unity of the Universe, the patterns of the processes committed in it and the causal relationship of all observed phenomena have a deep philosophical meaning and serve as a justification for the scientific materialist worldview.

The emergence and evolution of stars are the central problem of cosmogony.

In the observed picture of the structure of the Galaxy, the distribution of stars are carried out by their ages. In addition to the ball and scattered star clusters, there are special groups of stars in the galaxy, homogeneous in their physical characteristics. They are open Acad. V.A. Ambartsumian and named star associations. Star Associations are unstable formations, since their stars constituting with high speeds are running out in various directions. This determines the rapid pace of their collapse and the short time of the existence that does not exceed several million years. Therefore, the presence of stars in the Association indicates their recent occurrence, since they have not yet managed to leave the association and mix with the surrounding stars.

Star Association Research led Acad. V.A. Ambartsumian to the conclusion that the galaxy stars arose undesigned that the formation of stars is an unfinished process, ongoing and now, and that star associations are those places of galaxies in which the group formation of stars occurred.

In modern cosmogonia, there are two points of view on the emergence of stars: 1) the stars arise in the process of decaying super-proper bodies leading to a decrease in the density of the substance, and 2) the stars are formed as a result of the gravitational condensation of the diffusing substance accompanied by an increase in its density. However, the results of observations do not allow currently to give preference to any of them.

According to the hypothesis proposed by Acad. V. A. Ambartsumian stars are formed from super-density doster, emitted with explosions occurring in galaxic nuclei. The galaxies kernel contain small body sizes, many orders of stars, excellent in their physical nature, from stars and diffuse matter. These super-global bodies seem to be a new form of matter, unknown to modern science. The decomposition of superlock bodies - the protost train leads to the simultaneous formation of star groups - associations. However, V.A. Ambartsumian does not consider the mechanism of transformation of the protocimation into star groups and clusters.

The hypothesis of the origin of stars from diffuse matter was developed by some American scientists and other astronomers. Compression of a rarefied gas-dust medium under the influence of the forces and magnetic field of the Galaxy leads to the formation of individual clots representing protocons - globules. The continued compression of the protostar leads to an increase in pressure and temperature of the venerants. When the temperature in the center of the protostar reaches several million degrees, the thermalide reactions of the conversion of hydrogen in helium, accompanied by the release of a large amount of energy begins.

From this time, the protozing compression stops, since the gravitational forces are equalized by gas and light pressure, relatively soon protocol becomes the star of the main sequence of the chart of the spectrum-luminosity. The period of forming a star from diffuse matter depends on the mass of the initial thickening and continues no more than 100 million years.

On the main sequence, the star spends most of the time of its existence, until the hydrogen is "will be" in its central part. For a star with a mass equal to the mass of the Sun, this time is about 10 billion years. Massive hot stars emit so much energy that their hydrogen is enough for only a few million years. During the stay on the main sequence, the star retains almost unchanged radius, surface temperature and luminosity.

When the burnout of hydrogen in the star's core ends, the pressure from the inside can no longer balance the stars and the kernel of the star begins to shrink. The nucleus compression is accompanied by an increase in temperature. The increasing radiation expands the stars shell, increases its luminosity. Further evolution of the star depends on its mass. Most scientists believe that the stars of a small mass, comparable with solar, turn into white dwarfs.

The evolution of the star in the event of its occurrence as a result of the decay of the super-propelled protoster should have a different character, since after the formation of a star in its depths there is still a part of the super-proper doster. About its presence may indicate, for example, a sharp change in the brilliance of flashing incorrect stars. The outbreak process resembles an explosion and can be explained by the removal of the doster from the depths of the star to its surface, accompanied by the liberation of large quantities of Egergia.

With any character of evolution, a change in the chemical composition of the star as a result of education in its depths of heavier chemical elements is occurring.

In the process of its evolution, the star continuously loses the mass not only by radiation, but also by scattering the substance of its atmosphere, which is one of the sources of replenishment of interstellar diffuse matter.

Determination of distances and dimensions of galaxies

In the second half of the XVIII century, in addition to stars, a lot of fixed foggy spots was noticed in the sky - nebulae. The nature of the majority of them remained controversial for a long time. Only in the mid-20s of our century it turned out that most of them are the grand star systems, according to their size comparable with our galaxy. Therefore, they got the name of galaxies.

The totality of all galaxies is the largest system known to us, called the metagalaxy. Until her borders, we have not gotten, and whether it has a center - unknown.

This problem was cardinal to clarify the nature of such foggy spots and about their place in the universe, the center of which a person suffered from the ground first to the Sun, then to the center of our galaxy,

Before middle XX The century of the galaxy was considered to be small objects located inside our galaxy along with star clusters and gas nebula. They considered even in the 20s that these are lenses consisting of dust and illuminated from the inside with one bright star in their center. The way to determine the distance was opened by the staff of the Harvard Observatory, and then Lundmark and Hubble. The first of them were established that in the magtellated clouds, looking like scraps of the Milky Way, a lot of cepheid can be seen - periodic variable stars, in which the period of changing the gloss grows with their visible glitter. Cefeid was almost no visible around the magtellane clouds, and it was clear that the visible concentration in the clouds is the result of the spatial concentration of Cefeide in them, and the differences in their visible shine correspond to the differences in their true power - in luminosity. So it was discovered the most important property of Cefeide, which turned out to be fair everywhere, namely the existence of the ratio of the period - the luminosity. Having established (with difficulty because of their range from us) the luminosity of the cepheid of different periods nearest to us, it was possible from the comparison of their visible shine in our galaxy and in the magtel clouds to establish, how many times the last Cefeids coming to us. It turned out that Magellanov's clouds are outside our galaxy. The linear size of them, determined by the visible angular size and now known now, was several times less than our galaxy, but they still represent gigantic star systems. They contain millions of stars, gas nebulae and hundreds of stellar clusters similar to our. Magellanov's clouds were the first systems opened abroad of our galaxy. But they have an irregular shape, and this has not yet spoken about the nature of the most interesting nebulae spiral species.

Only in the nearest to us galaxies can be recognized among the brightest stars and, identifying their periods, find their distance more precisely than on new signs.

In 1924, Lundmark and Virts found them in a small number of measured already spectral (on the principle of Doppler - FIZO) radial velocities, which galaxies are removed from us in all directions and the sooner they are further from us. The speed of this removal of Hubble determined around 1930, 550 km / s per each megaparsec distance, and therefore the opening of the red bias is usually attributed to it. Continuous effects of the effect, mainly due to an increase in the distance scale to the nearest galaxies, has now brought a permanent chabble to the values \u200b\u200bof about 50 km / (with MPS), but most astrophysics still prefer to enjoy earlier definition but \u003d 75 km / (with MPS ) Perhaps waiting for a wave of new results, fluctuating between 100 and 50 km / (with MPS).

The structure and properties of galaxies

These parameters are the most important characteristics of stellar systems.

The masses of individual galaxies are set, determining the curve of their rotation, which in the central region is close to solid state; Then there is a gradual transition to the rotation by the law of the Kepler, when the distance from the central mass is already high, the density of the density is small and the mass of the outside region is relatively small. The rotation curves are obtained by the optical method, having a spectrograph slit along the visible large axis of the Galaxy image, and the success is the greater, the closer the plane of its rotation to the beam of view. Measurements are limited to the central, bright part of the galaxy and provide only the lower limit of its mass.

A detailed interpretation of the rotation curve of the part of the distribution of density ps inside the galaxy require further refinement. To do this, it is necessary to adopt the model of the Galaxy: a flat or model in the form of an inhomogeneous spheroid, in which the surfaces of a constant density are similar spheroids, or even more complex shape.

The masses of flat systems begin approximately from 10 ^ 11 (to the degree 11) Â and decrease to the masses of stellar clusters.

where V is a circular speed in the Kepler curve;

R - radius; G - gravitational force.

The masses of elliptic and the masses of spiral galaxies can be pulled in the case of pairs of double galaxies, in which the difference of global speeds can assume an equal speed of circulation, like spectral-double stars. However, there remains an unknown angle of inclination of the orbit, and it is impossible to determine the speed curve. We only get the lower limit of the sum of the mass of two galaxies, as in the case of spectral-double stars.

Above the question of the questions relating here, but you need to add much more.

The shape of the spiral branches, as it turned out, well corresponds to the logarithmic spiral

r \u003d. r (0) EXR (CA),

where a \u003d pj: 180 and c \u003d stgm, or

lG R \u003d LG R (0) + CCJ,

where from \u003d (P / 180) * LG E \u003d 0.00758.

Here m is a characteristic angle between the radius-vector point of the spiral and tangent to it. Of course, here is due to the true form of branches in their plane, and not a form distorted by the projection. On average m \u003d 73 ° and varies within 54-86 °. The first value corresponds to widely opened branches, the second refers to the spirals approaching the circle.

It happens that branches have several different forms. There are galaxies with three-four branches and such that have branches internal and external, or "dilapidated". Rather, the last branches are not solid, but consist of arcs that are not related to each other. Two- and even three-tiered spiral galaxies indicate the complexity of these phenomena of nature. Even earlier, Hubble discovered that there are galaxies with the "crossbar" - in English "bar", - in the center of which is their core, and spiral branches depart from the ends of the bar, but there are also those in which the branches depart from the middle of the bar; The latter represent the difficulty for the theory that considers the branch of the "expiration" from the bar. The flow of gas from the kernel along the bar with speeds up to 100 km / s is discovered. In the region of the spiral branches, in most cases, the rotation is close to the solid-state, and the point of the inflection on the rotation curve is where the branches are no longer traced, although the glow of the system stretches far away. Often the branches are not separated from the bar, but from the periphery of the ring, for which the bar is a diameter.

Many debates caused the question of the direction of rotation of the Galaxik - whether it is so that the branches are "dirty" or, on the contrary, "unwound." This is important for the theory of their origin. The sharpness of the question was smoothed when the galaxies were found, having both branches of opposite directions, i.e. Some "distillation", other "unwinding". If rotation is almost solidly, then no interference for the branches of any form.

Hubble introduced notation for simple spirals - S, for "crossed spirals" (with a bar) - SV. For intermediate forms (very short bar), Sav or others were introduced. Incorrect galaxies, he denoted through I or IR, but there are two types of their varieties. Elliptic galaxies for Hubble are denoted by the letter E with the addition of the numbers from 1 to 7, which indicates the compression ratio determined by the attitude

where but and B. - Visible diameters (usually distorted by the projection). Then he found "Lenzoid" galaxies with "Baljem" (large core), surrounded by a disk in which there are no spirals. He denoted them to S0. Further observations have shown that the Hubble classification does not reflect the entire variety of existing forms and properties of galaxies, and several other classifications were proposed, even faster than "lagging behind", and we will not stop on them.

Hubble introduced the following important additions. Now they have to give another, deeper meaning than Hubble assumed. Amorphous, structureless spiral branches that do not contain supergingants and poor gas are noted by the prefix A (SA). Very ridiccated branches with a variety of hot giants and rich in gas nebulae - with (SC), and the intermediate species spirals are marked with a b (SB). Such is M 31 (SB), and M 33 is SC. Our galaxy can relate to the SBC type - an intermediate spiral. The SC kernel is significantly less than that of SB. But SA, contrary to the opinion of Hubble, they are different.

After many attempts to theoretically explain the existence of spiral galaxies if there is no strictly solid-state rotation, the theory was very popular, the foundations of which laid Lin and Shu in the 60s.

Of great interest is the knowledge of how the galaxies are distributed on the lumows, which to some extent reflects their distribution and by weight, since with the same composition of the stars included in them, the mass is proportional to the luminosity. This provision is more justified for the same type of galaxies, especially the Elliptic ray, which has no big difference in either the structure or in color. But first they tried to get the overall picture for all types of galaxies together, and then it seemed that dwarf galaxies with absolute value M \u003d - 16 (to the degree M) and less little. But then they opened quite a lot of very weak and small galaxies in the vicinity of our galaxy.

The spatial structure of the galaxies of types E and S0 can be found by calculating spatial densities in the radius function from the results of the exact photometry of their surface brightness. The brightness, measured at points along the visible radius, is created by the radiation of all stars lying on the beam of our vision - on chords spheroid. From brightness in the projection, you can go through the condition of the presence of central symmetry to the volumetric brightness.

The structure of the metagalaxy, clusters.

Separate galaxies are often combined into a pair of comparable systems with each other or consist of one large galaxy and one or even several satellites with smaller luminosity, dimensions and masses.

Little groups of galaxies can also be seen. Some of them, more often, part of their members are only random projections of galaxies located closer or further. The most close couples and groups with members definitely related to each other physically are interacting systems - nests and chains of systems.

Finally, there are accumulations of galaxies both poor and scattered and rich, focusing towards the center of the accumulation of hundreds and many thousands of galaxies.

Much efforts are attached to attempts to detect the accumulations of galaxies - systems that would be the units of the highest order as "bricks" of the metagalaxy. Real existence of them has not yet been proven.

In the clusters, the elliptical E and lenzide galaxies S0 are strongly dominated, and in the general field between them are numerous spirals.

Double galaxies. Holmberg in Sweden made a catalog of double and multiple galaxies in the amount of about 8007, but, unfortunately, it does not satisfy modern requirements. In any case, Holmberg's hypothesis that double galaxies arise as a result of gravitational capture, it is necessary to leave. According to modern ideas, the pairs, groups and clusters of galaxies, as such, arose in the early stages of their formation.

I. D. Karachentsev introduced the concept of isolated galaxies, the visible distance between which is five or more and more than a distance of the distance to another closest galaxy, and compiled a catalog of 603 pairs.

It should be noted that in any catalog of such galaxies there is no information about the distance from us to each component, and therefore there is no confidence in the real proximity of their component to each other. Therefore, I. D. Karachentsa and other astronomers stubbornly worked on the definition of a red bias component. Of these, they find and the difference in the speeds of the component, helping to estimate the mass of the systems and the relationship of their mass to the luminosity.

The mass of the pair of galaxies is proportional to the square of their speed difference (it is assumed that their movement is orbital) and the distance between the components. But we do not know inclination to the beam of the orbit and the length of the line connecting the components, and therefore we use the average most likely of their values. Page in the United States, which received the speed of many pairs, showed that the masses defined by this method are an order of magnitude more masses that could be found from the study of the rotation of galaxies or dispersion of speeds in them. More accurate measurements of speeds in SAO on a 6-meter telescope This difference is eliminated in the mass definition. Half "isolated pairs" consists of interacting galaxies. According to White, the typical orbital period in pairs is 200 10 6 years, and the typical distance between them is about 40 kPs. Up to 15% of all galaxies are included in the pair, but it is still difficult to clarify the percentage of optical steam due to a random projection. Experiments I.D. Karachentseva and A. L. Shcherbanovsky using a computer showed that optical pairs are only about 10%, but the number it depends on the conditions for determining the concept of duality.

Groups. Holmberg highlighted triple and multiple galaxies from the field. No matter how to determine them, the number of objects will quickly decrease with the transition to increasingly multiplicity. On the other hand, the groups of galaxies are distinguished; For example, the vocauor gave a list of 54 groups and their members. But these very extensive groups contain up to dozen members, moving, probably in poor clusters, poor clusters are moving into rich, consisting of hundreds, and maybe tens of thousands of members. Almost no one group, even small, there is no information about the radial speed of each member. From several data, it is often possible to conclude that by applying the theorem of the virila, we will get positive energy indicating the instability of the group. V. A. Ambartsumian interprets it as a sign of youth of such groups and considers them young.

Other astronomers do not agree with him and believe that all groups must be stable, and this requires data from these speeds of greater mass; Therefore, they talk about the "hidden mass." The staff of the cobler contains in some unknown mean of the galaxy, only those designed for the group. Ya. E. Einasto believes that gigantic galaxies have a huge halo (like M 87) and they represent the "hidden mass". However, the more members in the system, the greater the "hidden mass" should be, so the contribution of the crown would be completely insufficient, but the crown of astronomers do not believe, and in general, the problems of the sustainability of the groups and the existence of "hidden masses" have not yet been resolved.

The most indisputable and most interesting groups are nests of interacting galaxies; Among the last to the least close is the Quintet Stephen from five galaxies. But in it, as in the VV 172 chain and some others, there is a member with an abnormal red displacement. Arp suggests that such groups have been thrown out of large galaxies.

Accumulations of galaxies. The closest to us accumulation of galaxies, rather, the cloud of them, which includes many large and bright spirals containing gas and dust, will be on us at 12 MPS and is in the cluster of the Virgin. Similar close cloud is located in a big bear. Each of them contains hundreds of galaxies. But more interest is the rich balls of galaxies concentrating to their center. The nearest of them - in the hair of Veronica, the 70 MPS, which contains the single exceptions to the elliptic E and the lenzide galaxies S0, in which the gas or not at all or is not enough. The number of galaxies in the clusters of such a "correct" type is set only to any limit visible star magnitude. The brightest members of the correct clusters are giant galaxies and the immutability of these values \u200b\u200bis used to estimate the distance to very distant clusters, the definition of the red displacement of which is impossible for technical reasons. Zvikki recorded clusters with the number of visible members of at least 50. In large, concentrated clusters closest to us, there are more than 10,000 members. Establishing an accomplice to the accumulation of individual members of red displacement with a large number of members is extreme difficulties. Counting members of the cluster in the distance function from the center make, sulfing from the density of galaxies of clusters the density of galaxies of the sky background nearby. So, it was established that in the rich proper clusters, the course of the numerical density on the area is similar to the number of particles in the isothermal gas ball as distance from the center.

Taking a wider neighborhood, L. S. Sharov showed the presence of a dense nucleus galaxies and an extensive crown; In addition, there is a segregation of some types of galaxies, for example, more concentrating to the center. The largest number of red displacements (about 50) is measured in the cluster of the coma. In such cases, the dispersion of the velocities of members can be estimated; It can also be estimated according to the luminosity function of galaxies in a cluster, normalizing it and knowing the luminosity with a mass for elliptic galaxies. The masses of rich clusters are 10 14 mass of the Sun (and more).

The unexpected compact cluster was opened by R. K. Shahbazyan. It turned out to be consisting of a dozen compact galaxies. The distance to it is 700 to me, and the size is only 350x180 kPs. The dispersion of radial speeds in it is inexplicably small: 62 km / s. Shahbazyan and Petrosyan were then discovered in the burdens for more dozens of those like the type of clusters, but they are not yet investigated.

It is very difficult to highlight dwarf members in the clusters, in particular, scattered poor spheroidal galaxies like a furnace and sculptor, as the latter are poorly visible due to low surface brightness, while others are difficult to distinguish from the galaxies of a distant background. The catalog of such galaxies of the sculptor type amounted to and examined in . E. Karacantsova.

Long searches led to the conclusion that only in a few clusters there is an extremely weak overall glow created, probably dwarf galaxies. On the other hand, a small amount of dust differ in them, noticeably absorbing light.

Neutral hydrogen in clusters is not detected, but there is a radio emission, which comes from the existing hypothesis B.V. High gas commerga in crowns of giant members of the cluster. It was found in clusters and x-rays, especially strong from the NGC 1275 radio party in the row of peers. Eibell on the Palomar Sky atlas found 2712 very rich clusters, and Zwicks were revealed by the same material and rank tens of thousands of clusters with the number of members at least 50 and briefly classified them.

These data serve as a material for a huge number of attempts to detect clusters of clusters, otherwise supercount. Some authors do not see them, others believe that they found, others believe that the definitions of this concept are different. Those who believe that ultrasound is found are found in their composition of only three - four clusters, which would be called only to a multiple galaxy, in the rank of the same clusters credited systems containing at least dozens of stars. Therefore, the author believes that while still clusters of clusters are not detected, at least they can exist. His opinion shares, apparently, Eibell, previously identified such super-scopleys. The statistical methods used in these searches are forced to rely on the zwick catalog, which gives the contour of the cluster. The boundaries of even simple clusters are very unreliable. B. I. Fesenko believes that with such works, strong distortion introduces the incredible influence of the rod of intergalactic light absorption in Pasha Galaxy. He also seems doubtful statement of the cobler, that the clouds and groups of clusters (closer than 5 MPS) are formed by the clouds (closer than 5 MPS) form a flattened super-relief with the center in the cluster of the Virgin.

Some special cases of late evolution of galaxies

In recent years, it has repeatedly tried to create models of the star composition of galaxies that would meet the observed integral spectra of bright (central) regions of spiral and elliptic galaxies. (Get good spectrograms of weakly luminous, but extensive parts of galaxies, disk and spiral branches are not yet possible.) In the model, such a mixture of stars of different spectra and luminosities should be selected so that it is given by the proportions of their number giving a spectrum similar to the observed. It turns out that these areas of galaxies must contain more red dwarfs than stars near the sun. These models are not quite perfect. Therefore, even if the number of the theory for different stages of the evolution of various stars are correct, the calculations of the evolution of the total star composition of galaxies can not be tested with confidence. V. A. Ambartsumyan, comparing the visible instability of small groups and clusters of galaxies with the existence of the core activity, came to the thought of the likelihood of early fragmentation of the doster, turning it into split stars in associations and galaxies in groups. This dispersion of the substance instead of its condensation, he considers what is happening in the modern era.

The idea of \u200b\u200bcondensation of the diffuse substance in the stars, rising to the Herschel hypothesis, is more common. In recent years, this hypothesis has evolved in the theory of star formation when the shock wave of compression is driving in gas. Star formation in our era is associated with the presence of young hot stars in the field of movement and compression of cold gases with dust. But the systems themselves relate to the very long era of the evolution of the metagalaxy, and all groups of galaxies and their satellites are considered to have arisen only long ago.

In contrast to this, the study of the interaction of galaxies led the author of this review to the conviction that sometimes on the periphery of flat galaxies, in particular at the end of the spiral branch, there are thickening of mass and glow, which are separated by several from the spiral branch and from part of the spiral galaxy, thereby turning into its satellite . They vary them from the mass of a small region of H i i to the mass, comparable to the mass of the parent galaxy, such as in the well-known system M51. Tidal theory is ready to attach ties from the already existing companion itself the occurrence of spiral branches, but most of these satellites are so small by weight, which is not able to create the required powerful tidal forces. Empathy, fragmentation occurs in the nests and in chains of galaxies that should be unstable already from Ea his Forms. In the cases studied by 1980, the internal velocities of the component were amazingly small.

BIBLIOGRAPHY

2. Vorontsov-Veljaminov B. A., 1978 - extragalactic astronomy,

2-E. ed. - M.: Science.

3. The origin and evolution of galaxies and stars / ed. S.B. Picelner.- M.: Science, 1976.

4. Problems of modern cosmogony / ed. V. A. Ayabartzumyana.-M.: Science, 1969.

5. Berbjj J., Barbage M., 1969 - quasary. - M.: Peace.

6. The structure of stellar systems / ed. P. N. Holowova.-M.: Il, 1962.

7. Zeldovich L. B., Novikov I. D., 1967 - Relativistic Astrophysics. - M.: Science.

8. Stars and star systems. / Under. ed. D.Ya. Martynova.-M.: 1981

9. Volynsky B.A. , Astronomy.-M.: 1971

Federal Education Agency
State Educational Institution of Higher Professional Education
"Chelyabinsk State Pedagogical University" (GOU VPO "ChGPU")

Abstract on the concept of modern natural science

Topic: Physical Nature Stars

Performed: Rapowkina T. I.
543 Group
Checked: Barkova V.V.

Chelyabinsk - 2012.
CONTENT
Introduction .................................................................................... 3
Chapter 1. What is the star ............................................................... 4

1.2 Evolution of stars ..................................................................... 10
1.3 End of the Star ...................................................................................... .14
Chapter 2. Physical Nature Stars ................................................ ..24
2.1 Luminativity ......................................................... ................24
2.2 Temperature .................................................................... .. ... 26
2.3 Spectra and chemical composition of stars ............................................. 27
2.4 Average Star density ........................................................................28
2.5 Radius of stars ............................................................................39
2.6 Mass stars ........................................................................... 30
Conclusion ............................................................ .................. ..32
References ....................................... .............................. 33
Appendix .............................................................................. 34

Introduction

There is nothing more simple than the star ...
(A. S. Eddington)

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.
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.
Stars are very interesting for me, so I decided to write an essay on this topic.
Stars are distant Suns, on this, studying the nature of the stars, we will compare their physical characteristics with the physical characteristics of the Sun.

Chapter 1. What is a star
1.1 Essence of Star
With attentive looking at the star appears to be a glowing point, sometimes with diverging rays. The ray phenomenon is associated with a feature of sight and is not related to the physical nature of the star.
Any star is the sun removed from us. The nearest of the stars - Proksima - is located 270000 times further from us than the sun. The brightest star of Sirius Sirius in the constellation is a big dog, located at a distance of 8x1013km, has about the same brightness as the 100-watt light bulb at a distance of 8 km (if you do not take into account the weakening of light in the atmosphere). But in order for the light to be visible at the same angle, under which the disc was visible to the distant sirium, its diameter should be 1 mm!
With good visibility and normal vision over the horizon, about 2500 stars can be seen at the same time. Have their own names of 275 stars, for example, Algol, Aldebaran, Antares, Altair, Arktur, Bethelgeuse, Vega, Gemma, Duzhe, Canopus (the second in the brightness of the star), Capella, Mitsar, Polar (guiding star), Regul, Rigel, Sirius, Specker, Heart of Charles, Taigaet, Fomalgaut, Sheat, Famine, Electra, etc.
The question of how many stars in this constellation is deprived of meaning, since it lacks concreteness. For the answer, you need to know the visual view of the observer, the time when observations are underway (the brightness of the sky), the height of the constellation (the horizon is difficult to detect a weak star due to the atmospheric weakening of light), the place of observation (in the mountains atmosphere, more transparent - so you can see More stars), etc. On average, one constellation accounts for about 60 stars observed by the naked eye (at the Milky Way and in large constellations - most). For example, in the constellation, the swan can be counted up to 150 stars (the Milky Way region); And in the constellation Lion - only 70. In a small constellation, the triangle shows only 15 stars.
If you take into account the stars up to 100 times weaker than the weakest stars, another distinguishable observer, then on average, one constellation will account for about 10,000 stars.
Stars differ not only by their brightness, but also in color. For example, Aldebaran (Constellation Taurus), Antares (Scorpio), Bethelgeuse (Orion) and Arcturus (Vascha) - Red, and Vega (Lira), Regul (Lion), Specker (Virgo) and Sirius (Big Pens) - White and Blue .
Stars flicker. This phenomenon is well noticeable at the horizon. The cause of the flicker is the optical inhomogeneity of the atmosphere. Before getting into the eye of the observer, the light of the stars crosses in the atmosphere a lot of small inhomogeneities. According to its optical properties, they look like lenses concentrating or scattering light. Continuous movement of such lenses and is the cause of flicker.
The reason for changing the color in the flicker explains Fig.6, from which it can be seen that the blue (C) and red (k) light from the same star before entering the eye of the observer (O), it takes unequal paths in the atmosphere. This is a consequence of unequal refractions in the atmosphere of blue and red light. The inconsistency of the vibrant oscillations (caused by different heterogeneities) leads to the unbalancement of colors.

Fig.6.
Unlike overall flicker, color can only be seen from stars close to the horizon.
Some stars called by variable stars, brightness changes occur much more slowly and smoothly than when flickering, fig. 7. For example, the star Algol (Devil) in the constellation Perseus changes its brightness with a period of 2.867 days. The causes of "variability" of stars are diverse. If two stars turn around the common center of the masses, then one of them can periodically close the other (the case of Algol). In addition, some stars change brightness in the process of pulsation. For other stars, brightness changes with explosions on the surface. Sometimes the whole star is exploded (then there is a supernova star, the luminosity of which Billions times above the sunny).

Fig.7.
The movements of the stars relative to a friend with speeds in tens of kilometers per second lead to a gradual change in star patterns in the sky. However, the life expectancy of a person is too small that such changes have been able to notice with the unarmed eyes when observed.

1.2 Birth of stars

Modern astronomy has a large number of arguments in favor of the assertion that the stars are formed by condensing the clouds of the gas-dust interstellar medium. The process of formation of stars from this environment continues at present. The clarification of this circumstance is one of the largest achievements of modern astronomy. It was even relatively recently believed that all the stars were formed almost at the same time many billion years ago. The collapse of these metaphysical representations contributed, above all, the progress of observational astronomy and the development of the theory of structure and the evolution of stars. As a result, it became clear that many observed stars are relatively young objects, and some of them arose when there was a person on earth.
An important argument in favor of the withdrawal that the stars are formed from the interstellar gas-dusty environment, serves the location of the groups of obviously young stars (so-called "associations") in the spiral branches of the Galaxy. The fact is that, according to radio astronomy observations, the interstellar gas is concentrated mainly in the spiral sleeves of galaxies. In particular, it takes place in our galaxy. Moreover, from detailed "radio images" some of some galaxies close to us it follows that the largest density of interstellar gas is observed on the internal (with respect to the center of the corresponding galaxy) the edges of the spiral, which finds a natural explanation, we will not stop here on the details. But it is precisely in these parts of the spirals that are observed by the methods of optical astronomy "Zones N N", i.e., clouds of ionized interstellar gas. The reason for the ionization of such clouds can only be the ultraviolet radiation of massive hot stars - objects of obviously young.
The central in the problem of the evolution of stars is the question of the sources of their energy. In the last century and at the beginning of this century, various hypotheses were offered about the nature of the sources of energy of the sun and stars. Some scientists, for example, believed that the source of solar energy is continuous falling on its surface of meteors, others searched for a source in the continuous compression of the Sun. The potential energy could be released at such a process, under certain conditions, "go to radiation. As we will see, below, this source at an early stage of the star evolution can be quite effective, but it cannot provide the radiation of the Sun for the required time.
The successes of nuclear physics made it possible to solve the problem of star-energy sources in the late thirties of our century. Such a source is thermonuclear synthesis reactions that occur in the depths of stars with a dominant very high temperature (about ten million degrees).
As a result of these reactions, the speed of which is highly dependent on temperature, protons turn into a helium nucleus, and the exempted energy slowly "seeps" through the subsoil of stars and in the end, significantly transformed, is emitted to world space. This is an exceptionally powerful source. If we assume that the original sun consisted only from hydrogen, which, as a result of thermonuclear reactions, will become entirely in helium, then the amount of energy will be allocated to approximately 10,52 ERG. Thus, to maintain radiation at the observed level for billions of years, it is enough that the Sun "spent" is not over 10% of its initial stock of hydrogen.
Now we can present a picture of the evolution of some star as follows. For some reason (several of them can be specified), the cloud of the interstellar gas-dusty environment can be condensed. Quite soon (of course, on astronomical scale!) Influenced by the global strength of this cloud, a relatively dense opaque gas ball is formed. Strictly speaking, this ball cannot be called a star, since in its central areas the temperature is insufficient in order to begin thermonuclear reactions. The gas pressure inside the ball is unable to balance the forces of attraction of individual parts, so it will continuously compress. Some astronomers have previously believed that such protosons are observed in separate nebulae in the form of very dark compact formations, the so-called global. The successes of radio astronomy, however, forced to refuse such a rather naive point of view. Usually, not one protocol is formed simultaneously, but a more or less numerous group of them. In the future, these groups become star associations and clusters, well-known astronomers. It is very likely (that at this very early stage of the star evolution around it is formed with a smaller mass, which are then gradually turning into the planets.
In the compression of the protozal, the temperature increases it and a significant part of the released potential energy is emitted to the surrounding space. Since the dimensions of the compressive gas ball are very high, then radiation from the unit of its surface will be insignificant. Since the stream of radiation from the surface unit is proportional to the fourth degree of temperature (Stephen - Boltzmann's law), the temperature of the surface layers of the star is relatively low, while its luminosity is almost the same as the ordinary star with the same mass. Therefore, on the "Spectrum" diagram, such stars will be right from the main sequence, i.e. they will fall into the region of red giants or red dwarfs, depending on the values \u200b\u200bof their initial masses.
In the future, the protocol continues to shrink. Its bells are becoming smaller, and the surface temperature grows as a result of which the spectrum is becoming increasingly early. Thus, moving along the "Spectrum - Luminativity" diagram, the protocol is quite quickly "sits" to the main sequence. During this period, the temperature of the star subsoil is already sufficient for that so that thermonuclear reactions began there. At the same time, the gas pressure inside the future star balances the attraction and the gas ball stops compressing. The protocol becomes a star.

Gorgeous columns consisting mainly of gaseous hydrogen and dust give rise to newborn stars inside the eagle nebula.

Photo: NASA, ESA, Stci, J Hester And P Scowen (Arizon State University)

1.3 Evolution of Star
In order to pass the earliest stage of its evolution, the protociments need a relatively little time. If, for example, the mass of the protoconstar is more solar, you need only a few million years, if less - several hundred million years. Since the time of evolution of the protost train is relatively small, this very early phase of the star development find it difficult. Yet stars in such a stage, apparently, are observed. We mean very interesting stars type T Torets, usually immersed in dark nebulae.
In 5966, completely unexpectedly revealed the opportunity to observe protosons in the early stages of their evolution. Veliko was the surprise of radio astronomers when, during the sky review on a wave of 18 cm, an appropriate radio station, it was discovered bright, extremely compact (i.e. having small angular sizes) sources. It was so unexpected that the first time refused to even believe that such bright radar can belong to the hydroxyl molecule. A hypothesis was expressed that these lines belong to some unknown substance, which was immediately given by the "suitable" name "Misterium". However, Misterium very soon divided the fate of his optical "brothers" - "Nebulia" and "Konnoye". The fact is that many decades are bright line of nebulae and the solar crown did not give in to identifying with any known spectral lines. Therefore, they were attributed to some, unknown on earth, hypothetical elements - "Nebulia" and "Koronia". In 1939-1941 It was convincingly shown that the mysterious lines "crown" belong to repeatedly ionized atoms of iron, nickel and calcium.
If for the "debate" "nebulia" and "crown" required decades, after a few weeks after the discovery it became clear that the Misryerium lines belong to ordinary hydroxyl, but only in unusual conditions.
So, the sources of Miserium are giant, natural cosmic mars working on the wavelength of the hydroxyl line, the length of which is 18 cm. It is in the maasers (and on optical and infrared frequencies - in lasers) a huge brightness in the line is achieved, and the spectral width of it is small . As is known, the increase in radiation in the lines due to this effect is possible when the medium in which the radiation is distributed, in any way "activated". This means that some "third-party" source of energy (the so-called "pumping") makes the concentration of atoms or molecules on the initial (upper) level abnormally high. Without permanent "pumping", a maser or laser is impossible. The question of the nature of the "pumping" mechanism of space masers, while food is finally resolved. However, most likely "pumping" is quite powerful infrared radiation. Another possible "pumping" mechanism may be some chemical reactions.
The pumping mechanism of these Masers is still not entirely clear, it is still possible to make a rough idea of \u200b\u200bphysical conditions in the clouds emitting a moman mechanism of a line of 18 cm. First of all, it turns out that these clouds are quite dense: there is an extreme in the cubic centimeter EXle 10,8 -10 9 particles, and significant (and may be big) part of them - molecules. The temperature is hardly higher than two thousand degrees, most likely it is about 1000 degrees. These properties are sharply different from the properties of even the most dense clouds of interstellar gas. Given the relatively small size of the clouds, we involuntarily come to the conclusion that they are rather reminiscent of the extended, pretty cold atmosphere of stars - supergiant. It is very similar to that these clouds are nothing but an early stage of development of the protost train, next immediately behind their condensation from the interstellar medium. In favor of this statement (which the author of this book expressed back in 1966) they say other facts. In the nebulae, where cosmic maasers are observed, young hot stars are visible. Consequently, there recently ended and, most likely, continues at present, the process of star formation. Perhaps the most curious thing is that, as radio astronomy observations show, cosmic mares of this type, as it were, are "immersed" in small, very dense clouds of ionized hydrogen. In these clouds there are many cosmic dust, which makes them unobservable in the optical range. Such "cocoons" are ionized by a young, hot star, located inside them. In the study of star formation processes, infrared astronomy was very useful. After all, for infrared rays, the interstellar absorption of light is not so essential.
We can now present the following picture: from the cloud of the interstellar medium, by means of its condensation, several clots of different masses are formed, evolving into protosts. Evolution speed is different: for more massive clots it will be more. Therefore, the most massive clot will turn into a hot star to the hot star, while the rest will be delayed more or less for a long time at the protosal stage. We observe them as the sources of maser radiation in the immediate vicinity of the "newborn" hot star, an ionisive, which did not condense in the clutch of the Cokoon Hydrogen. Of course, this rough scheme will continue to be refined, and, of course, significant changes will be made to it. But the fact remains: unexpectedly it turned out that some time (most likely - relatively short) newborn protocons, figuratively expressing, "screaming" about their appearance to light, using the latest methods of quantum radiophysics (i.e. marsers).
Once at the main sequence and having ceased to burn, the star radiates almost without changing its position in the "Spectrum" diagram. Its radiation is maintained by thermonuclear reactions going in the central regions. Thus, the main sequence is as it were as if the geometric location of the points in the "Spectrum - luminosity" diagram, where the star (depending on its mass) can be long and resistant to emit due to thermonuclear reactions. The location of the star on the main sequence is determined by its mass. It should be noted that there is another parameter that determines the position of the equilibrium emitting star on the "Spectrum" diagram. This parameter is the initial chemical composition of the star. If the relative content of heavy elements decreases, the star "falls" in the diagram below. It is this circumstance that the presence of a sequence of subcarlikov is explained. As mentioned above, the relative content of heavy elements from these stars is ten times less than that of the stars of the main sequence.
Star stay on the main sequence is determined by its initial mass. If the mass is large, the radiation of the star has a huge power and it rather quickly consumes the reserves of its hydrogen "fuel." For example, the stars of the main sequence with a mass exceeding the solar per few dozen times (these are hot blue giants of the spectral class O), it may be stable to emit, while on this sequence only a few million years, while stars with a mass close to Solar, are on the main sequence of 10-15 billion years.
"Burnout" of hydrogen (i.e., turning it into helium during thermonuclear reactions) occurs only in the central areas of the stars. This is explained by the fact that the stellar substance is mixed only in the central areas of the stars, where nuclear reactions are coming, while the outer elephant retains the relative hydrogen content unchanged. Since the amount of hydrogen in the central areas of the star is limited, sooner or later (depending on the mass of the star) it is almost the whole "burn out." Calculations show that the mass and radius of its central region, in which nuclear reactions are coming, gradually decrease, while the star slowly moves in the "Spectrum - Luminativity" diagram to the right. This process occurs significantly faster from relatively massive stars.
What happens to the star when all (or almost all) hydrogen in her core "will burn"? Since the release of energy in the central areas of the star is terminated, the temperature and pressure cannot be maintained there at the level necessary to counteract the strength of a compressive star. The star kernel will begin to shrink, and it will rise it. A very dense hot area is formed, consisting of helium (which has turned hydrogen) with a small admixture of heavier elements. Gas in such a state is called "degenerate". It has a number of interesting properties. In this dense hot area, nuclear reactions will not occur, but they will rather intensively flow on the periphery of the kernel, in a relatively thin layer. The star, as it were, "swells", and will begin to "go" from the main sequence, moving in the field of red giants. Further, it turns out that the stars of giants with a smaller content of heavy elements will have higher luminosity with the same sizes.

The evolution of the star class G on the example of the Sun:

1.4 End of Star
What happens to the stars when the "helium-carbon" reaction in the central regions exhausted itself, as well as the hydrogen reaction in a thin layer surrounding the hot tight nucleus? What stage of evolution will come after the Stage of the Red Giant?

White dwarfs

The combination of these observations, as well as a number of theoretical considerations, suggest that at this stage of the evolution of the star, the mass of which is less than 1.2 mass of the Sun, a substantial part of their mass forming their outer shell, "reset". We observe such a process seems to be the formation of the so-called "planetary nebulaes". After the star is separated from a relatively low speed, the outer shell, "expound" its internal, very hot layers. At the same time, the separated shell will expand, farther and further away from the star.
Powerful ultraviolet star radiation - the core of the planetary nebula - will ionize atoms in the shell, exciting their glow. After a few tens of thousands of years, the shell will dispel and only a small very hot dense star will remain. Gradually, pretty slow cooling, it will turn into a white dwarf.
Thus, white dwarfs, as it were, "ripen" inside the stars - red giants - and "appear on the light" after separating the outer layers of giant stars. In other cases, the discharge of the outer layers may not occur by the formation of planetary nebulae, but by the gradual expiration of atoms. Anyway, white dwarfs in which all the hydrogen "burned out" and nuclear reactions stopped, apparently, are the final stage of the evolution of most stars. The logical conclusion from here is the recognition of the genetic relationship between the most late stages of the evolution of stars and white dwarfs.

White dwarfs with carbon atmosphere

At a distance of 500 light years from the Earth in the constellation Aquarius there is a dying star of the type of sun. Over the past few thousand years, this star gave rise to snail nebula - well-studied close planetary nebula. The planetary nebula is the usual end stage of evolution for stars of this type. In this image of the nebula, the snail made by the infrared cosmic observatory shows the radiation coming mainly on the expanding shells of molecular hydrogen. Dust, which is usually present in such nebula, should also be intensively emitted in the infrared range. However, it seems that it is absent in this nebula. The reason may be located in the central star - White Dwarf. This small, but very hot star radiates energy in a shortwave ultraviolet range and is therefore not visible on the infrared image. Astronomers believe that over time, this intensive ultraviolet radiation could destroy dust. It is expected that the Sun will also pass the stage of the planetary nebula in 5 billion years.

At first glance, the nebula of snail (or NGC 7293) has a simple round shape. OD-NAO now has become clear that this well-studied planetary nebula, generated by the Sun-like star, approaching the end of his life, has an amazingly complex structure. Its extended loops and the comets of gas-pepped bunches were investigated on images obtained by the Hubble Space Telescope. However, this clear image of the snail nebula was obtained on a telescope with a lens diameter of just 16 inches (40.6 cm), equipped with a chamber and a set of broadband and narrow-band filters. On the color composite image you can see the details of the structure, including blue-green radial strips, or needles, length ~ 1 Light year, which make the nebula like a bicycle cosmic wheel. The presence of the spokes, apparently, testifies that the nebula of the snail itself is an old, which has been protected by the planetary nebula. The nebula is located at a distance of only 700 light years from the Earth in the constellation of Aquarius.

Black dwarfs

Gradually cooling, they are less and less emitted, turning into invisible "black" dwarfs. These are dead, cold stars of very large density, in millions of times more denser of water. Their size is less than the sizes of the globe, although the masses are comparable to the solar. The cooling process of white dwarfs lasts a lot of hundreds of millions of years. So cums your existence most stars. However, the final of the life of relatively massive stars can be significantly, more dramatic.

Neutron stars

If the mass of the shrinking star exceeds the mass of the sun by more than 1.4 times, then such a star, reaching the white dwarf stage, will not stop. The gravitational forces in this case are very high that electrons are pressed into atomic nuclei. As a result, isotopes turn into neutrons capable of flying to each other without any intervals. The density of neutron stars is superior to even the density of white dwarfs; But if the mass of the material does not exceed 3 solar masses, neutrons, like electrons, are capable of preventing further compression. A typical neutron star has in the diameter just from 10 to 15 km, and one cubic centimeter of its substance weighs about a billion tons. In addition to unheardly huge density, neutron stars have two more special properties that allow them to be discovered, despite such small dimensions: this is a rapid rotation and a strong magnetic field. In general, all the stars rotate, but when the star is compressed, its speed increases - just as a figure skater rotates much faster when he presses his arms. The neutron star makes several revolutions per second. Along with this, exceptionally rapid rotation, neutron stars have a magnetic field, millions of times stronger than the earth.

Hubble saw a single neutron star in space.

Pulsary

The first pulsars were opened in 1968, when radio astronomers discovered regular signals that go to us from four galaxy points. Scientists were amazed by the fact that some natural objects can emit radio pulses in such a right and fast rhythm. At first, the truth, the astronomer suspects the participation of certain thinking creatures living in the depths of the Galaxy. But soon a natural explanation was found. In a powerful magnetic field of neutron star, electrons moving on the helix generate radio waves, which are emitted by a narrow beam as a spotlight beam. The star rotates rapidly, and the radar intersects the line of our observation, as if the lighthouse. Some pulsars emit not only radio waves, but also light, x-ray and gamma rays. The period of the most slow pulsars about four seconds, and the fastest - thousandths of seconds. The rotation of these neutron stars was for some reason even more accelerated; They may be included in dual systems.
Thanks to the draft distributed computing [Email Protected] For 2012, 63 Pulsar was found.

Dark Pulsar

Supernovae

Stars whose masses do not reach 1.4 solar, die quietly and serene. What happens to more massive stars? How do neutron stars and black holes arise? A catastrophic explosion, which ends the life of a massive star is truly an impressive event. This is the most powerful natural phenomena in the stars. A moment is released more energy than empties our sun for 10 billion years. The light stream sent by one dying star is equivalent to a whole galaxy, and after all, the visible light is only a small share of full energy. The remains of the exploded star are flying away with speeds up to 20,000 km per second.
Such grand star explosions are called supernova. Supernovae is a rather rare phenomenon. Each year and other galaxies are detected from 20 to 30 supernovae, mainly as a result of systematic search. In a century, in each galaxy, they can be from one to four. However, in our own supernova galaxy, they were not observed from 1604. Maybe they were, but remained invisible due to the large amount of dust in the Milky Way.

The explosion of a supernovae.

Black holes

From a star having a lot of more than three solar, and the radius is more than 8.85 kilometers, the light can no longer get into space. The beam carved from the surface is curved in the gravity field so much that returns back to the surface. Quanta light
etc.................

The luminosity of stars is calculated by their absolute star magnitude, which is associated with the visible star magnitude M ratios

M \u003d M + 5 + 51Gπ (116)

M \u003d m + 5 - 51gr, (117)

where π is a one-year parallax star, expressed in the states of the arc (") and R - the distance of the stars in parrseca (PS). Found by formulas (116) and (117) The absolute star value μ belongs to the same mind as the visible stellar value m, i.e. it may be visual μ V, photographic M pg, photovoltaic (M V, M in or M V), etc. In particular, the absolute bolometric star, which characterizes complete radiation,

M B \u003d M V + B (118)

and can also be calculated according to the visible bolometry of the chesky star

m B \u003d M V + B, (119)

where b is a bolometric correction, depending on the spectral class and the class of star luminosity.

The luminosity of L stars is expressed in the luminosity of the Sun, adopted per unit (L \u003d 1), and then

lG L \u003d 0.4 (M - m), (120)

where M is the absolute star size: visual m v \u003d +4 m, 79; photographic m pg - \u003d + 5m, 36; photoelectric yellow μ ν \u003d +4 m 77; Photoelectric blue m B \u003d 5 m, 40; Bolometric M B \u003d +4 m, 73. These stellar values \u200b\u200bmust be used when solving the tasks of this section.

The luminosity of the star computed by the formula (120) corresponds to the type of absolute star magnitudes of the star and the Sun.

The law of Stephen Boltzmann

apply to determine the effective temperature T e of only those stars in which the angular diameters are known. If the ε is the amount of energy falling from the star or the sun along the normal to the site in 1 cm 2 borders of the earth's atmosphere for 1C, then with an angular diameter δ, expressed in the state of the arc ("), temperature

(121)

where σ \u003d 1.354 · 10 -12 cal / (cm 2 · · · hail 4) \u003d 5.70 · 10 -5 erg / (cm2 · · · hail 4) and is selected depending on the amount of energy of the amount of Energy E, which is located From formula (111) on the difference in bolometric star magnitudes of the star and the Sun by comparing with the solar constant ε ~ 2 cal / (cm2 · min).

The color temperature of the sun and stars, in the spectra of which the distribution of energy is known, can be found by the law of wine

Τ \u003d k / λ m, (122)

where λ M is the wavelength corresponding to the maximum of energy, and K is a constant depending on the units of measurement λ. When measuring λ in cm k \u003d 0.2898 cm · hail, and when measuring λ in angstroms (Å) k \u003d 2898 · 10 4 Å · degrees.

With a sufficient precision, the color temperatures of the stars are calculated according to their color indicators C and (B-V)

(123)

(124)

The masses of μ stars are usually expressed in the masses of the Sun (μ \u003d 1) and are securely determined only for physical double stars (with a known parallax π) according to the third generalized Capler's law: the amount of the mass components of the double star

Μ 1 + m 2 \u003d a 3 / p 2, (125)

where ρ is the period of circulation of the star-satellite around the main star (or both stars around the common center of the masses), expressed in years, and a is a large semi-axle of the orbit of the star-satellite in astronomical units (a. e.).

The value is in a. e. It is calculated on the angular value of the large semi-axis A and pararallax π obtained from observations in the second arc seconds:

a \u003d A "/ π (126)

If the ratio of distances A 1 and a 2 components of the double star from their common center of mass, then equality

M 1 / m 2 \u003d a 2 / a 1 (127)

allows you to calculate the mass of each component separately.

Linear radii R stars are always expressed in the radius of the Sun (R \u003d 1) and for stars with known angular diameters δ (in the second arc)

(128)

lGΔ \u003d 5,444 - 0.2 M B -2 LG T (129)

Linear stars radius are also calculated by formulas

lGR \u003d 8,473-0.20m b -2 LGT (130)

lGR \u003d 0.82C-0.20M V + 0.51 (131)

and lGR \u003d 0.72 (B - V) - 0.20 m V + 0.51, (132)

in which T - the temperature of the star (strictly speaking, effective, but if it is not known, then color).

Since the volumes of stars are always expressed in the volume of the Sun, then they are proportional to R 3, and therefore the average density of the star substance (the average density of the stars)

(133)

where ρ is a rapid density of the solar substance.

At ρ \u003d 1, the average density of the star is obtained in the densities of the solar substance; If you need to calculate ρ in g / cm3, ρ \u003d 1.41 g / cm 3 should be taken.

Star or Sun Radiation Power

(134)

and the monthly weight loss through radiation is determined by the Einstein formula

(135)

where C \u003d 3 · 10 10 cm / s is the speed of light, Δμ - expressed in grams per second and ε 0 - in Erghah per second.

Example 1.Determine the effective temperature and radius of the stars of entrances (and the lyrics), if its angular diameter is 0 ", 0035, one-year pararallax 0", 123 and a bolometric brilliance - 0 m, 54. The bolometric star value of the Sun is -26 m, 84, and the solar constant is close to 2 kal / (cm 2 · min).

Data: Vega, Δ \u003d 3 ", 5 · 10 -3, π \u003d 0", 123, m B \u003d -0 m, 54;

Sun, M B \u003d - 26M, 84, E \u003d 2 CAL / (cm 2 · min) \u003d 1/30 Cal / (cm 2 · s); Permanent σ \u003d 1.354 x 10 -12 Cal / (cm 2 · · · hail 4).

Decision. Falling normally per unit area of \u200b\u200bthe earth surface Radiation of a star similar to the solar constant is calculated by formula (111):

lg e / e \u003d 0.4 (m b - m b) \u003d 0.4 (-26 m, 84 + 0 m, 54) \u003d -10,520 \u003d -11 + 0,480,

where e / e \u003d 3.02 · 10 -11,

or Ε \u003d 3.02 · 10 -11 · 1/30 \u003d 1.007 · 10 -12 CAL / (CM2 · C).

According to (121), effective star temperature

According to the formula (128), the radius

Example 2.Find the physical characteristics of the Sirius star (A large PSA) and its satellite according to the following observation data: the visible yellow starry value of Sirius is -1 m, 46, its main color indicator is 0 m, 00, and the star satellite, respectively +8 m, 50 and +0 m, 15; Pararallax star is 0 ", 375; Satellite turns around Sirius with a period of 50 years in orbit with an angular value of a large half-axis 7", 60, and the ratio of the distances of both stars to the common center of mass is 2.3: 1. The absolute star magnitude in the yellow rays to take equal to +4 m, 77.

Data: Sirius, V 1 \u003d - 1 m, 46, (B-V) 1 \u003d 0 m, 00;

satellite, V 2 \u003d +8 m, 50, (b - v) 2 \u003d +0 m, 15, p \u003d 50 years, a "\u003d 7", 60; a 2 / a 1 \u003d 2.3: 1; n \u003d 0 ", 375.

Sun, M V \u003d +4 m, 77.

Decision. According to formulas (116) and (120), the absolute stellar value of Sirius

M v1 \u003d v 1 + 5 + 5 lps \u003d -1 m, 46 + 5 + 5 lg 0.375 \u003d +1 m, 41, and its logarithm of its luminosity

where the luminosity l 1 \u003d 22.

By formula (124), Sirius temperature

by formula (132)

and then the radius of Sirius R 1 \u003d 1.7, and its volume R 1 3 \u003d 1.7 3 \u003d 4.91 (Sun volume).

The same formulas are given for sirium satellite: M v2 \u003d +11 m, 37; L 2 \u003d 2.3 · 10 -3; T 2 \u003d 9100 °; R 2 \u003d 0.022; R 2 3 \u003d 10.6 · 10 -6.

By Formula (126), a large part of the satellite orbit

according to (125) the sum of the masses of both stars

and, according to (127), the ratio of mass

where with a joint solution of equations (125) and (127) there is a mass of sirium μ 1 \u003d 2.3 and the mass of its satellite m 2 \u003d 1.0

The average stars density is calculated by the formula (133): Sirius

and his companion

According to the found characteristics - radius, luminosity and density - it can be seen that Sirius belongs to the stars of the main sequence, and its satellite is white dwarf.

Task 284.Calculate the visual luminosity of stars, visual shine and one-year pararallax of which are indicated in brackets: α eagle (0m, 89 and 0 ", 198), α small bear (2m, 14 and 0", 005) and ε Indian (4m, 73 and 0 ", 285).

Task 285.Find the photographic luminosity of stars for which visual shine, the usual color indicator and the distance from the Sun are indicated in brackets: β twins (LM, 21, 1M, 25 and 10.75 PS); η lion (3m, 58, + 0m, 00 and 500 ps); Karttein Star (8m, 85, + 1m, 30 and 3.98 PS). The star value of the Sun is indicated in the task 275.

Task 286.How many times the visual luminosity of stars of the previous task exceeds their photographic luminosity?

Task 287.The visual brilliance of Capella (and the ease) is 0m, 21, and its satellite is 10m, 0. The color indicators of these stars are equal to + 0m, 82 and + 1m, 63 respectively. Determine how many times the visual and photographic luminosity of the chapel is greater than the corresponding luminosity of its satellite.

Task 288.The absolute visual star the star β is large PSA - 2M, 28. Find the visual and photographic luminosity of two stars, one of which (with a color indicator + 0m, 29) is 120 times absolutely brighter, and the other (with a color indicator + 0m, 90) is 120 times an absolutely weaker than the stars β of large PSA.

Task 289.If the sun, the Rigel (β O Orion), Toliman (and Centaurus) and his proxim satellite (nearest) were at the same distance from the Earth, how much would it receive from these stars in comparison with solar? Visual brilliance of Rigel 0m, 34, its pararallax 0 ", 003, the same values \u200b\u200bof Tolimiman 0m, 12 and 0", 751, and at the proxy 10m, 68 and 0 ", 762. The star value of the Sun is specified in the task 275.

Task 290.Find distances from the sun and parallaxes of three stars Big Mesmen for their brilliance in yellow rays and an absolute star magnitude in blue rays:

1) A, V \u003d 1M, 79, (B-V) \u003d + LM, 07 and MB \u003d + 0m, 32;

2) δ, v \u003d 3m, 31, (β-V) \u003d + 0m, 08 and MB \u003d + 1m, 97;

3) η, v \u003d 1m, 86, (B-V) \u003d -0m, 19 and mV \u003d - 5m, 32.

Task 291.At what distance from the sun is the star of the Speaker (and the Virgin) and what is its parallax, if its luminosity in the yellow rays is 720, the main figure of the color is -0M, 23, and the shine in the blue rays 0m, 74?

Task 292.Absolute blue (in in-ray) Star magnitude of the star of Capella (and the eagerness) + 0m, 20, a passing stars (and small ps) + 3m, 09. How many times these stars in the blue rays are absolutely brighter or weaker the stars of the regulator (and the lion), the absolute yellow (in the V ray) of which is -0m, 69, and the main color indicator -0m, 11?

Task 293.What the sun looks like from the distance of the star Toliman (and Centaurus), whose parallax is 0 ", 751?

Task 294.What is the visual and photographic shine of the Sun from the distances of the regulators (A Lion), Antaresa (and Scorpion) and Bethelgeuse (and Orion), whose parallaxes are respectively 0 ", 039, 0", 019 and 0 ", 005?

Task 295.How many bolometric corrections differ from the main indicators of the color with the bolometric luminosity of the star greater than 20, 10 and 2 times its yellow luminosity, which, in turn, is greater than the blue luminosity of the star, respectively, at 5, 2 and 0.8 times?

Task 296.Maximum energy in the spectrum of the spoke (and the virgin) falls on an electromagnetic wave with a length of 1450 Å, in the spectrum of chapels (and the ease) -n 4830 Å and in the spectrum of Polluks (β twins) -n 6580 Å. Determine the flower temperature of these stars.

Task 297.The solar constant periodically ranges from 1.93 to 2.00 kal / (cm 2 · min) how much does the effective temperature of the sun, the visible diameter of which is close to 32 "? Permanent Stephen σ \u003d 1,354 10 -12 kal / ( cm 2 · · hail 4).

Task 298.According to the previous problem, find the approximate value of the wavelength corresponding to the maximum of energy in the solar spectrum.

Task 299.Determine the effective temperature of the stars in the measured angular diameters and reaching the radiation, indicated in brackets from them:

α lion (0 ", 0014 and 3.23 · 10 -11 kal / (cm 2 · min));

α eagle (0 ", 0030 and 2.13 · 10-11 kal / (cm 2 · min));

α Orion (0 ", 046 and 7.70 · 10 -11 Cal / (cm 2 · min)).

Task 300.The visible bolometric star magnitude α Eridan is -1m, 00 and the angular diameter 0 ", 0019, at the stars α of the crane the similar parameters + 1m, 00 and 0", 0010, and the star α Taurus + 0m, 06 and 0 ", 0180 . Calculate the temperature of these stars, adopting the visible bolometric star the sun equal to -26m, 84 and the solar constant close to 2 kal / (cm2 min).

Task 301.Determine the temperature of the stars, the visual and photographic glitter of which is indicated in brackets: γ Orion (1M, 70 and 1M, 41); ε Hercules (3m, 92 and 3m, 92); α Persea (1m, 90 and 2m, 46); β Andromeda (2m, 37 and 3m, 94).

Task 302.Calculate the temperature of stars on photovoltaic yellow and blue star values \u200b\u200bindicated in brackets: ε large PSA (1M, 50 and 1M, 29); β Orion (0m, 13 and 0m, 10); α keel (-0m, 75 and - 0m, 60); α Aquarius (2m, 87 and 3m, 71); α Volopasses (-0m, 05 and 1m, 18); α whale (2m, 53 and 4m, 17).

Task 303.According to the results of the two previous tasks, find the wavelength corresponding to the maximum of energy in the spectra of the same stars.

Task 304.The stars run (and the lira) pararallax 0 ", 123 and the angular diameter 0", 0035, at Altair (A Eagle) similar parameters 0 ", 198 and 0", 0030, in the riglel (β original) - 0 ", 003 and 0 ", 0027 and Aldebaran (and Taurus) - 0", 048 and 0 ", 0200. Find radii and volumes of these stars.

Task 305.Glitter Deneba (a swan) in the blue rays 1m, 34, its main color indicator + 0m, 09 and pararallax 0 ", 004; the same parameters for the star ε twins are 4m, 38, + 1m, 40 and 0", 009, And at the stars γ Eridan 4M, 54, + 1m, 60 and 0, 003. Find the radii and volumes of these stars.

Task 306.Compare the diameters of the star Δ of the snakes and barnard stars, the temperature of which is the same if the first star has a visible bolometric star value equal to 1M, 03 and pararallax 0 ", 029, and the second the same parameters 8m, 1 and 0", 545.

Task 307.Calculate linear radii of stars, temperature and absolute bolometric star magnitude of which are known: in α whale 3200 ° and -6m, 75, in β lion 9100 ° and + 1m, 18, and in ε Indian 4000 ° and + 6m, 42.

Task 308.What is equal to the angular and linear stars diameters, the visible bolometric star, the temperature and pararallax of which are listed in brackets: η large bear (-0m, 41, 15500 ° and 0 ", 004), ε large bear (+ lm, 09, 10 000 ° and 0 ", 008) and β dragon (+ 2m, 36, 5200 ° and 0", 009)?

Task 309.If two stars are approximately the same temperature, radii differ in 20, 100 and 500 times, then how many times their bolometric luminosity differ?

Task 310.How many times the radius of the star α Aquarius (the spectral subclass G2IB) exceeds the radius of the sun (the spectral subclass G2V), if its visual visual star value is 3m, 19, a bolometric correction -0m, 42 and pararallax 0 ", 003, the temperature of both shines is about the same, And the absolute bolometric star size of the sun is equal to + 4m, 73?

Task 311.Calculate the bolometric correction for the stars of the G2V spectral subclass, to which the Sun belongs if the angular diameter of the Sun 32 ", its visible visual star value is -26m, 78 and the effective temperature of 5800 °.

Task 312.To find the approximate value of the bolometric correction for the stars of the spectral subclass of the B0IA, to which the star ε Orion belongs, if its angular diameter 0 ", 0007, visible. The visual star value is 1M, 75 and the maximum of energy in its spectrum falls on the wavelength of 1094 Å.

Task 313.Calculate the radius and the average density of the stars specified in problem 285, if the weight of the twins β is approximately 3.7, the mass of the lion is close to 4.0, and the mass of the Karttein stars 0.5.

Task 314.The visual brilliance of the polar star 2M, 14, its usual color figure + 0m, 57, pararallax 0 ", 005 and the mass is equal to 10. The same parameters for the star Fomalgaut (and South Fish) 1m, 29, + 0m, 11, 0", 144 and 2.5, and the stars Wang manena 12m, 3, + 0m, 50, 0 ", 236 and 1.1. Determine the luminosity, the radius and the average density of each star and indicate its position on the Herzshprung - Ressel diagram.

Task 315.Find the sum of the mass components of the double star ε Hydra, whose parallax 0 ", 010, the period of satellite circuit 15 years and the angular dimensions of the large semi-axis orbit 0", 21.

Task 316.Find the sum of the mass components of the double star α large bear, pararallax of which 0 ", 031, the period of circulation of the satellite 44.7 years and the angular dimensions of the large semi-axis of its orbit 0", 63.

Task 317.Calculate the masses of components of double stars according to the following data:

Task 318.For the main stars of the previous task, calculate the radius, volume and middle density. The visible yellow star value and the main color indicator of these stars: α is 0m, 08 and + 0m, 80, α 2m, 00 and + 0m, 04 and ξ, a large bear 3M, 79 and + 0m, 59.

Task 319.For the sun and stars specified in Task 299, find the power of radiation and mass loss per second, day and year. The parallaxes of these stars are as follows: α lion 0 ", 039, α eagle 0", 198 and α orion 0 ", 005.

Task 320.According to the results of the previous problem, calculate the duration of the observed intensity of the radiation of the Sun and the same stars, believing it possible to the loss of half of its modern mass, which (in the masses of the Sun) in α of the lion is 5.0, in α Eagle 2.0 and α α ORION 15 . Mass to take equal to 2 · 10 33

Task 321.Determine the physical characteristics of the components of the double star (and small PSA) and indicate their position on the Herzshprung-Ressel diagram, if the observations are known: the visual glitter of the transmission is 0m, 48, its normal color figure + 0m, 40, visible bolometric star 0m, 43 , angular diameter 0 ", 0057 and pararallax 0", 288; Visual brilliance of the satellite of the transmission 10m, 81, its usual color indicator + 0m, 26, the appeal period around the main star - 40.6 years in orbit with a visible large half-axis 4 ", 55; ratio of distances of both stars from their common center of mass equal to 19: 7.

Task 322.Solve the previous task for the double star α centaution. At the main star, a photoelectric yellow star value is 0m, 33, the main figure of color + 0m, 63, the visible bolometric stellar value 0m, 28; The satellite has similar values \u200b\u200bof the essence of 1m, 70, + 1m, 00 and 1m, 12, the period of circulation of 80.1 years appeared on the average distance of 17 ", 6; Pararallax star 0", 751 and the ratio of distances of components from their total center of mass equal to 10 :nine.

Answers - the physical nature of the sun and stars

Multiples and variable stars

The gloss ε of a multiple star is equal to the amount of gloss ε i of all its components

E \u003d E 1 + E 2 + E 3 + ... \u003d σe ί, (136)

and therefore its visible t and absolute μ Star magnitude is always less than the corresponding stellar magnitude M I and M I of any component. Puting in Pigonson Formula (111)

lG (E / E 0) \u003d 0.4 (M 0 -M)

E 0 \u003d 1 and M 0 \u003d 0, we get:

lG E \u003d - 0.4 m. (137)

Determining the gloss E i of each component according to formula (137), they are found according to the formula (136) the total shine ε of a multiple star and again according to formula (137) are calculated M \u003d -2.5 LG E.

If the lines of the components are given

E 1 / E 2 \u003d k,

E 3 / E 1 \u003d n

and so on, then the gloss of all components is expressed through the brilliance of one of them, for example, E 2 \u003d E 1 / k, ε 3 \u003d n ε 1, etc., and then, by formula (136), are found by E.

The average orbital velocity of the components of the elaborate variable of the star can be found in the periodic largest displacement of Δλ of lines (with a wavelength λ) from their middle position in its spectrum, since in this case you can take

v \u003d V R \u003d C (Δλ / λ) (138)

where V r is a radial speed and C \u003d 3 · 10 5 km / s - the speed of light.

According to the found values \u200b\u200bof V components and the period of variability of the ρ, the stars calculate the large semi-axis a 1 and a 2 of their absolute orbits:

a 1 \u003d (V 1 / 2P) P and A 2 \u003d (V 2 / 2P) P (139)

then - a large part of the relative orbit

a \u003d a 1 + a 2 (140)

and finally, according to the formulas (125) and (127) -Mass components.

Formula (138) also makes it possible to calculate the rate of expansion of gas shells discarded by new and supernovae.

Example 1.Calculate the visible visual star magnitude of the triple star components, if its visual glitter is 3 m, 70, the second component is brighter than the third 2.8 times, and the first brighter third is 3 m, 32.

Data: m \u003d 3 m, 70; E 2 / E 3 \u003d 2.8; M 1 \u003d M 3 -3 M, 32.

Decision. By formula (137) we find

lGE \u003d - 0.4M \u003d - 0.4 · 3 m, 70 \u003d - 1,480 \u003d 2,520

To take advantage of formula (136), it is necessary to find the ratio E 1 / E 3; software (111),

lG (E 1 / E 3) \u003d 0.4 (M 3 -M 1) \u003d 0.4 · 3 m, 32 \u003d 1,328

from E 1 \u003d 21.3 E 3

According to (136),

E \u003d E 1 + E 2 + E s \u003d 21.3 E 3 + 2.8 E 3 + E 3 \u003d 25,1 E 3

E 3 \u003d E / 25,1 \u003d 0.03311 / 25,1 \u003d 0.001319 \u003d 0.00132

E 2 \u003d 2.8 E 3 \u003d 2.8 · 0.001319 \u003d 0.003693 \u003d 0.00369

and E 1 \u003d 21.3 E 3 \u003d 21.3 · 0.001319 \u003d 0.028094 \u003d 0.02809.

By formula (137)

m 1 \u003d - 2.5 LG E 1 \u003d - 2.5 · LG 0.02809 \u003d - 2.5 · 2.449 \u003d 3 m, 88,

m 2 \u003d - 2.5 lg e 2 \u003d - 2.5 · lg 0.00369 \u003d - 2.5 · 3,567 \u003d 6 m, 08,

m 3 \u003d -2.5 LG E 3 \u003d - 2.5 · LG 0.00132 \u003d - 2.5 · 3,121 \u003d 7 m, 20.

Example 2.In the spectrum of the eclipse variable, the brilliance of which is changing over 3.953 days, the lines relative to their middle position are periodically shifted to the opposite sides to the values \u200b\u200bof 1.9 · 10 -4 and 2.9 · 10 -4 from the normal wavelength. Calculate the masses of the components of this star.

Data: (Δλ / λ) 1 \u003d 1.9 · 10 -4; (Δλ / λ) 2 \u003d 2.9 · 10 -4; Ρ \u003d 3 d, 953.

Decision. By formula (138), the average orbital velocity of the first component

v 1 \u003d V R1 \u003d C (Δλ / λ) 1 \u003d 3 · 10 5 · 1.9 · 10 -4; V 1 \u003d 57 km / s,

Orbital speed of the second component

v 2 \u003d V R2 \u003d C (Δλ / λ) 2 \u003d 3 · 10 5 · 2.9 · 10 -4;

v 2 \u003d 87 km / s.

In order to calculate the values \u200b\u200bof the large semi-axes of the components, the period of circulation p, equal to the period of variability, express in seconds. Since 1 d \u003d 86400 s, then ρ \u003d 3,953 · 86400 c. Then, according to (139), the first component has a large fear of the orbit

a 1 \u003d 3.10 · 10 6 km,

and the second a 2 \u003d (V 2 / 2P) P \u003d (V 2 / V 1) A 1, \u003d (87/57) · 3.10 · 10 6;

a 2 \u003d 4.73 · 10 6 km,

and, software (140), a large semi-axle of relative orbits

a \u003d a 1 + a 2 \u003d 7.83 · 10 6; A \u003d 7.83 · 10 6 km.

To calculate the sum of the mass of components by formula (125), it should be expressed a in a. e. (1 or. e. \u003d 149.6 · 10 6 km) and p - in years (1 year \u003d 365 d, 3).

or M 1 + m 2 \u003d 1.22 ~ 1.2.

The ratio of the masses, according to formula (127),

and then μ 1 ~ 0.7 and m 2 ~ 0.5 (in the masses of the Sun).

Task 323.Determine the visual glitter of the double star α fish, the glitter of the components of which is 4m, 3 and 5m, 2.

Task 324.Calculate the brilliance of the four-fold star ε lira in the brilliance of its components, equal to 5m, 12; 6m, 03; 5m, 11 and 5m, 38.

Task 325.Visual brilliance of the dual star γ Aries 4m, 02, and the difference in the stellar values \u200b\u200bof its components is 0m, 08. Find the visible stellar magnitude of each component of this star.

Task 326.What brilliance of a triple star, if its first component is brighter than 3.6 times, the third is weaker than the second 4.2 times and has shine 4m, 36?

Task 327.Find an apparent star magnitude of a double star if one of the components has a 3M, 46 gloss, and the second one for 1M, 68 brighter of the first component.

Task 328.Calculate the stellar magnitude of the components of the triple star β unicorn with visual gloss 4m, 07, if the second component is weaker than the first 1.64 times and brighter than the third to 1M, 57.

Task 329.Find the visual luminosity of the components and the overall luminosity of the double stars α twins if its components have a visual brilliance of 1M, 99 and 2M, 85, and pararallax is 0 ", 072.

Task 330.Calculate the visual luminosity of the second component of the double star γ virgin if the visual brilliance of this star is 2M, 91, the brilliance of the first component 3M, 62, and pararallax 0 ", 101.

Task 331.Determine the visual luminosity of the components of the double star of Mitsar (ζ a large bear) if its glitter is 2M, 17, pararallax 0 ", 037, and the first component is a brighter second of 4.37 times.

Task 332.Find the photographic luminosity of the double star η of Cassiopeia, the visual brilliance of the components of which is 3m, 50 and 7m, 19, their usual color indicators + 0m, 571 and + 0m, 63, and the distance is 5.49 ps.

Task 333.Calculate the masses of the components of the elaborate variable stars according to the following data:

Star	Raduing speed of components	Alternation period
β Perseus u snakes ww e-cefay	44 km / s and 220 km / from 180 km / s and 205 km / from 117 km / s and 122 km / from 120 km / s and 200 km / s	2 d, 867 1 d, 677 2 d, 525 2 d, 493

Task 334.While how many times the visual brilliance of the variable stars β Persea and χ swan change, if the first star it ranges from 2m, 2 to 3m, 5, and the second-from 3m, 3 to 14m, 2?

Task 335.How many times the visual and bolometric luminosity of the variable stars α orion and α of Scorpion variable, if the first star visual glitter ranges from 0m, 4 to 1M, 3 and the bolometric correction corresponding to it from -3m, 1 to -3m, 4, and the second Stars - Glitter from 0m, 9 to 1m, 8 and bolometric correction from -2m, 8 to -3m, 0?

Task 336.In what limits and how many times the linear radii of the variable stars α α orion and α of Scorpion change, if the first star parallax is 0 ", 005 and the angular radius varies from 0", 034 (at the gloss maximum) to 0 ", 047 (in a minimum Brilliance), and the second - pararallax 0 ", 019 and the coal radius is 0", 028 to 0 ", 040?

Task 337.According to the tasks 335 and 336, calculate the temperature of Bethelgeuse and Antares at the maximum of their brilliance, if the temperature of the first star is 3200K, and the second - 3300K.

Task 338.How many times and with what daily gradient changes the luminosity in the yellow and blue rays of variable-cefeyid α variables, ζ twins, η eagle, τυ shield and Uz shield, whose variability information is as follows:

Task 339.According to the previous task, to find the amplitudes of the gloss change (in yellow and blue rays) and the main indicators of the color of stars, construct graphs of the dependence of amplitudes from the variability period and formulate the conclusion about the patterns detected by graphics.

Task 340.In the minimum of the brilliance, the visual star of the star Δ Cefhea 4M, 3, and the stars R triangle 12m, 6. What is the brilliance of these stars at the maximum of luminosity, if it increases with 2.1 and 760 times, respectively?

Task 341.The brilliance of the new eagle of 1918 has changed in 2.5 days from 10m, 5 to 1m, 1. How many times did it increase and how the average has changed for half a heels?

Task 342.The brilliance of the new swan, discovered on August 29, 1975, was close to the flash, and the maximum increased to 1M, 9. If we assume that on average, the absolute star magnitude of new stars at the gloss maximum is about -8m, which luminosity had this star to the outbreak and at the gloss maximum and what about the distance from the sun is located?

Task 343.Emisy hydrogen lines H5 (4861 A), and H1 (4340 a) in the spectrum of the new Eagle of 1918 were shifted to the purple end, respectively, 39.8 Å and 35.6 Å, and in the spectrum of the new swan in 1975 - by 40 , 5 Å and 36.2 Å. How fast was the gas shells discarded by these stars expanded?

Task 344.The angular dimensions of the M81 galaxy in the constellation of a large bear are equal to 35 "x14", and the Galaxies of M51 in the constellation of the racing POS-14 "X10", the greatest brilliance of supernovae, broke out at different times in these galaxies, was equal to 12m, 5 and 15m, 1 By applying the absolute star magnitude of supernovae at the gloss's maximum close to -15m, 0, calculate the distances to these galaxies and their linear dimensions.

Answers - multiple and variable stars

Description of the presentation on individual slides:

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White dwarf, the hottest of famous, and the planetary nebula NGC 2440, 07.05.2006 The physical nature of the stars

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Spectrum λ \u003d 380 ∻ 470 nm - purple, blue; λ \u003d 470 ∻ 500 nm - blue-green; λ \u003d 500 ∻ 560 nm - green; λ \u003d 560 ∻ 590 nm - yellow-orange λ \u003d 590 ∻ 760 nm-red. Distribution of colors in the spectrum \u003d k o z z r with f Remember, for example: how once Jacques Runor urban broke the lantern. In 1859 G.Krhghof (1824-1887, Germany) and R.V. Bunsen (1811-1899, Germany) opened spectral analysis: Gazi absorb the same wavelengths that radiate in the heated state. At the stars against the background of solid spectra, dark (fraunut vehicles) lines are observed - these are absorption spectra. In 1665, Isaac Newton (1643-1727) received Sunny radiation spectra and explained to their nature, showing that the color is its own property of light. In 1814, Josef von Fraungofer (1787-1826, Germany) discovered, and marked and 754 lines described in detail in a sunny spectrum (named after it), creating a spectroscope to observe the spectroscopes in 1814. Kirchhoff-Bunsen spectroscope

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The spectra of stars spectra of stars are their passport with a description of all stellar patterns. According to the spectrum of the star, you can find out its luminosity, the distance to the star, temperature, the study of star spectra is the foundation of modern astrophysics. Spectrogram of scattered accumulation of "Giada". William Hegins (1824-1910, England) Astronomer, first applying the spectrograph, began spectroscopy stars. In 1863, it showed that the spectra of the Sun and Stars have a lot of general and that their observed radiation is emitted by the hot substance and passes through the overlying layers of coarse absorbing gases. Combined star radiation spectrum. From above "natural" (visible in the spectroscope), from below - the dependence of the intensity on the wavelength. Size, chemical composition of its atmosphere, speed of rotation around the axis, movement features around the common center of gravity.

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Chemical composition The chemical composition is determined by the spectrum (intensity of fraun-roof lines), depending on the temperature, pressure and density of the photosphere, the presence of a magnetic field. Stars consist of the same chemical elements that are known on Earth, but mainly of hydrogen and helium (95-98% of the mass) and other ionized atoms, and in cold stars in the atmosphere there are neutral atoms and even molecules. As the temperature increases the composition of the particles capable of exist in the star atmosphere is simplified. Spectral analysis of stars of classes o, b, a (t from 50,000 to 10,0000) shows in their atmospheres the line of ionized hydrogen, helium and metal ions, in the class K (500 ° C) are already detected radicals, and in the class M (38000C) - molecules oxides. The chemical composition of the star reflects the influence of factors: the nature of the interstellar medium and those nuclear reactions that are developing in the star during its life. The initial composition of the star is close to the composition of interstellar matter from which a star arose. The remains of supernova NGC 6995 is a hot glowing gas formed after the explosion of a star 20-30 thousand years ago. Such explosions actively enriched by the space heavy elements of which subsequently formed planets and the next generation stars

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Color of stars in 1903-1907. Einar Herzshprung (1873-1967, Denmark) The first defines the colors of hundreds of bright stars. Stars have a variety of colors. Arcticu has a yellow-orange tint, a white-blue beelel, Antares bright red. The dominant color in the spectrum of the star depends on the temperature of its surface. The gas shell of the star behaves almost as an ideal emitter (absolutely black body) and fully obeys the classical laws of radiation M. PLANK (1835-1947) and V.Vina (1864-1928), binding body temperature and the nature of its radiation. The planet law describes the distribution of energy in the body spectrum and indicates that with increasing temperature, the total flux flow increases, and the maximum in the spectrum is shifted towards short waves. During the observations of the starry sky, they could see that the color (the property of the light cause a certain visual sensation) of stars was bottled. The color and range of stars is associated with their temperature. The light of different wavelengths excites different color sensations. The eye is sensitive to the wavelength carrier of the maximum energy λmamy \u003d B / T (the law of wine, 1896). Like the precious stones of the stars of scattered cluster NGC 290 are overflowed with various colors. Photo CT them. Hubble, April 2006

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Tempera temperature is directly related to color and spectrum. The first measurement of the temperature of the stars was produced in 1909 by the German Astronomer Julius Sheiner (1858-1913), having spent an absolute photometry of 109 stars. The temperature is determined by the spectra using the law of λmax.t \u003d b, where B \u003d 0.289782.107Å.k is constant wine. Bethelgei (a picture of the telescope named after Habble). In such cold stars with T \u003d 3000k, radiation in the red region of the spectrum predominate. In the spectra of such stars there are many lines of metals and molecules. Most stars have temperatures 2500K<Т< 50000К Звезда HD 93129A (созв. Корма) самая горячая – Т= 220000 К! Самые холодные - Гранатовая звезда (m Цефея), Мира (o Кита) – Т= 2300К e Возничего А - 1600 К.

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Spectral classification in 1866, Angelo Ski (1818-1878, Italy) gave the first spectral classic stars in color: white, yellowish, red. Harvard spectral classification was first presented in the star spectra catalog Henry Draper (1837-1882, USA), prepared under the leadership of E. Picering (1846-1919) by 1884. All spectra were placed on the intensity of the lines (later in the temperature sequence) and marked in alphabetical order from hot to cold stars: Obafgk M. By 1924, Anna Cannon was finally established (1863-1941, USA) and published catalog in 9 volumes at 225330 Star-directory HD.

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Modern spectral classification The most accurate spectral classification represents the MK system created by W. Murgan and F. Kinan in the Yerk Observatory in 1943, where the spectra are arranged both in temperature and the luminosity of stars. The luminosity classes marked by Roman numerals were additionally introduced: IA, IB, II, III, IV, V and VI, respectively indicating the size of stars. Additional classes R, N and S are indicated by the spectra similar to K and M, but with a different chemical composition. Between each two classes, subclasses were introduced marked with numbers from 0 to 9. For example, a spectrum of type A5 is in the middle between A0 and F0. Additional letters sometimes noted the features of the stars: "D" - dwarf, "D" - white dwarf, "p" - a pectile (unusual) spectrum. Our sun refers to the spectral class G2 V

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The luminosity of stars in 1856 Norman Pogson (1829-1891, England) establishes a formula for luminosities through absolute m. Star quantities (i.e., from a distance of 10 pcs). L1 / L2 \u003d 2.512 M2-M1. The scattered accumulation of "Pleiads" contains a lot of hot and bright stars that were formed at the same time from a gas-pepped cloud. Blue haze, accompanying "Pleiads", - scattered dust, reflecting the light of stars. Some stars are shining brighter, others are weaker. The luminosity of the star radiation is the total energy emitted by the star in 1 second. [J / C \u003d W] Stars Emit energy in the entire wavelength range L \u003d 3.846.1026W / with comparing the star with the Sun, we get L / L \u003d 2,512 M M, or LGL \u003d 0.4 (M -M ) Lighting stars: 1.3.10-5L

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The size of the stars determine: 1) direct measurement of the angular diameter of the star (for bright ≥2.5m, close stars,\u003e 50 is measured) using the Michelson interferometer. For the first time, on December 3, 1920, the corner diameter of the star Bethelgeuse (α Orion) \u003d A. Maykelson (1852-1931, USA) and F. Piz (1881-1938, USA). 2) through the luminosity of the star L \u003d 4πr2σt4 in comparison with the Sun. Stars over the rarest exception are observed as point light sources. Even in the biggest telescopes can not see their discs. According to its size, the stars are divided from 1953 to: supergiant (i) Bright giants (II) Giants (III) Subgigans (IV) Dwarfs of the main sequence (V) Subcarliki (VI) White Dwarfs (VII) Dwarf's names, giants and supergianta introduced Henry Resess in 1913, and opened them in 1905 Einar Herzshprung, introducing the name "White Dwarf". Sizes of stars 10 km

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The mass of stars is one of the most important characteristics of stars pointing to its evolution - determining the life of the star. Methods for determining: 1. Dependence Mass-luminosity L≈M3.9 2. 3rd Refined Capler Law in Physically Double Systems Theoretically Mass Stars 0.005m

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Nearby stars stars that cannot be seen with the naked eye are marked with gray designation spectrum. Class Star Limitability Temp, K radius mass paral. Star Star System View. abs. Sun G2V -26,58 4.84 1 5780 1.0 1 α Centavel proxim M5.5VE 11.05 15,53 0,000055 2900 0,145 0,12 0,772 "Centaurus A G2V -0.01 4.38 1.56 5790 1,227 0,907 0,747 "Centaur b K0V 1.33 5.71 0,453 5260 0,865 1,095 star barnard (ß snakesz) m4.0ve 9,54 13,22 0,0,0549 3200 0,161 0,166 0,547" Wolf 359 (CN Lion) M6.0V 13,53 16.55 0,000019 0.15 0.092 0.419 "LANDA 21185 (B.MEDVEDITA) M5.5E 7.50 10,448 0,00555 3500 0,448 0,393" Sirius (α large PSA) Sirius A A1V -1, 46 1.47 23.55 10400 1.7-1.9 2,14 0.380 "Sirius B DA2 8,68 11.34 0,00207 8000 0.92 1.03 LUYTEN 726-8 UV Whale M5.5E 13, 02 15.40 0.000042 2800 0.14 0,102 0.374 "BL whale M6.0E 12.52 15,85 0.000068 2800 0.14 0,109 Ross 154 (V1216 SHOP) M3.5VE 10.6 13.07 0, 000417 0,24 0,171 0,337 "Ross 248 (HH Andromeda) M5.5VE 12,29 14,79 0,000108 0.17 0,121 0,316" ε Eridan K2V 3,73 6,19 0,305 5100 0,84 0,850 0,310 "Lakail 9352 (CD-36 ° 15693) M1.5VE 9.75 0.52 0.529 0,304 "Ross 128 (FI VIA) M4.0VN 13,51 0.00054 0.16 0,156 0.299"

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Comparative characteristics of stars in size classes of stars mass M¤ dimensions R¤ Density g / cm3 Luminatibility L¤ lifetime, years% of the total number of stars The brightest supergigances up to 100 103-104<0,000001 >105 105 <0,000001 Сверхгиганты 50–100 102–103 0,000001 104–105 106 0,001 Яркие гиганты 10–100 > 100 0.00001\u003e 1000 107 0.01 Normal giants up to 50\u003e 10 0.0001\u003e 100 107-108 0,1 - 1 subgigances up to 10 to 10 0.001 to 100 108-109 Normal stars 0.005-5 0.1-5 0.1-10 0,0001-10 109-1011 to 90 - white to 5 3-5 0.1 10 109 - yellow 1 1 1,5 1 1010 - red 0.005 0,1 10 0.0001 1011-1013 White Dwarfs 0.01-1.5 to 0.007 103 0.0001 to 1017 to 10 neutron stars 1.5-3 (up to 10) 8-15 km (up to 50 km) 1013-1014 0.000001 to 1019 0,01- 0.001.