Solar core. The central part of the Sun with a radius of approximately kilometers, in which thermonuclear reactions occur, is called the solar core. The density of the material in the core is approximately kg/m³ (150 times the density of water and ~6.6 times the density of the densest metal on Earth, osmium), and the temperature in the center of the core is more than 14 million degrees.
Convective zone of the Sun. Closer to the surface of the Sun, vortex mixing of the plasma occurs, and the transfer of energy to the surface is accomplished primarily by the movements of the substance itself. This method of energy transfer is called convection, and the subsurface layer of the Sun, approximately km thick, where it occurs is the convective zone. According to modern data, its role in the physics of solar processes is exceptionally great, since it is in it that various movements of solar matter and magnetic fields originate.
Photosphere of the Sun. The photosphere (the layer that emits light) forms the visible surface of the Sun, from which the size of the Sun, the distance from the surface of the Sun, etc. are determined. The temperature in the photosphere reaches an average of 5800 K. Here, the average gas density is less than 1/1000 of the density of the earth's air.
Chromosphere of the Sun. The chromosphere is the outer shell of the Sun, about km thick, surrounding the photosphere. The origin of the name of this part of the solar atmosphere is associated with its reddish color. The upper boundary of the chromosphere does not have a distinct smooth surface; hot emissions called spicules constantly occur from it. The temperature of the chromosphere increases with altitude from 4000 to degrees.
Crown of the Sun. The corona is the last outer shell of the Sun. Despite its very high temperature, from up to degrees, it is visible to the naked eye only during a total solar eclipse.
“Black Holes of the Universe” - The history of ideas about black holes. The question of the real existence of black holes. Detection of black holes. Collapsed stars. Dark matter. Difficulty. Black holes and dark matter. Supermassive black holes. Hot dark matter. Cold dark matter. Warm dark matter. Primitive black holes.
“The physical nature of stars” - Betelgeuse. The luminosities of other stars are determined in relative units, compared with the luminosity of the Sun. Comparative sizes of the Sun and dwarfs. Stars can differ in luminosity by a billion times. Thus, the masses of stars differ by only a few hundred times. Our Sun is a yellow star, the temperature of the photosphere of which is about 6000 K. Capella, whose temperature is also about 6000 K, is the same color.
"Evolution of the Stars"- Supernova explosion. Orion Nebula. Compression is a consequence of gravitational instability, Newton's idea. The Universe consists of 98% stars. As the density of the cloud increases, it becomes opaque to radiation. Astronomers are unable to trace the life of one star from beginning to end. Eagle Nebula.
"Stars in the Sky" - General characteristics stars Evolution of stars. "Burnout" of hydrogen. Chemical composition. There are many legends about Ursa Major and Ursa Minor. Temperature determines the color of a star and its spectrum. Star radius. The winter sky is richest in bright stars. What did the ancient Greeks say about bears?
"Distances to the Stars"- Stars differ from each other in color and shine. Even the naked eye can see that the world around us is extremely diverse. Hipparchus. 1 parsec = 3.26 light years = 206,265 astronomical units = 3.083,1015 m Using spectral lines, you can estimate the luminosity of a star and then find its distance.
"Starry Sky"- Late in the evening you see many stars in the sky. Constellations. Name the constellations that you know. Planet Earth. The earth is the habitat of man. Planets. Stars in the sky. Light from the Sun reaches the Earth in 8.5 minutes. A legend has come down to us from the ancient Greeks. In 1609, Galileo first looked at the moon through a telescope.
There are a total of 17 presentations in the topic
Sources of energy from stars If the Sun consisted of coal and the source of its energy was combustion, then if the current level of energy radiation were maintained, the Sun would completely burn out in 5000 years. But the Sun has been shining for billions of years! If the Sun consisted of coal and the source of its energy was combustion, then if the current level of energy radiation were maintained, the Sun would completely burn out in 5000 years. But the Sun has been shining for billions of years! The question of the energy sources of stars was raised by Newton. He assumed that stars replenish their energy reserves due to falling comets. The question of the sources of energy of stars was raised by Newton. He assumed that stars replenish their energy reserves from falling comets. In 1845, German. Physicist Robert Meyer () tried to prove that the Sun shines due to the fall of interstellar matter on it. In 1845, German. Physicist Robert Meyer () tried to prove that the Sun shines due to the fall of interstellar matter onto it. Hermann Helmholtz suggested that the Sun emits part of the energy released during its slow compression. From simple calculations we can find out that the Sun would completely disappear in 23 million years, and this is too short. By the way, this source of energy, in principle, occurs before the stars enter the main sequence. Hermann Helmholtz suggested that the Sun emits part of the energy released during its slow compression. From simple calculations we can find out that the Sun would completely disappear in 23 million years, and this is too short. By the way, this source of energy, in principle, occurs before the stars reach the main sequence. Hermann Helmholtz (g.)
Internal structure of stars Sources of energy of stars At high temperatures and masses greater than 1.5 solar masses, the carbon cycle (CNO) dominates. Reaction (4) is the slowest - it takes about 1 million years. In this case, a little less energy is released, because more of it is carried away by neutrinos. At high temperatures and masses of more than 1.5 solar masses, the carbon cycle (CNO) dominates. Reaction (4) is the slowest - it takes about 1 million years. In this case, a little less energy is released, because more than it is carried away by neutrinos. This cycle was independently developed by Hans Bethe and Karl Friedrich von Weizsäcker in 1938. This cycle was independently developed by Hans Bethe and Karl Friedrich von Weizsäcker in 1938.
Internal structure of stars Sources of energy of stars When the combustion of helium in the interior of stars ends, at higher temperatures other reactions become possible in which heavier elements are synthesized, up to iron and nickel. These are a-reactions, carbon combustion, oxygen combustion, silicon combustion... When the combustion of helium in the bowels of stars ends, at higher temperatures other reactions become possible in which heavier elements are synthesized, up to iron and nickel. These are a-reactions, carbon combustion, oxygen combustion, silicon combustion... Thus, the Sun and planets were formed from the “ash” of supernovae that exploded long ago. Thus, the Sun and planets were formed from the “ash” of supernovae that exploded long ago.
Internal structure of stars Models of the structure of stars In 1926, Arthur Eddington’s book “The Internal Structure of Stars” was published, with which, one might say, the study of the internal structure of stars began. In 1926, Arthur Eddington’s book “The Internal Structure of Stars” was published, with which , one might say, the study of the internal structure of stars began. Eddington made an assumption about the equilibrium state of main sequence stars, i.e., the equality of the energy flux generated in the interior of the star and the energy emitted from its surface. Eddington made an assumption about the equilibrium state of main sequence stars, i.e., equality the flow of energy generated in the interior of a star and the energy emitted from its surface. Eddington did not imagine the source of this energy, but quite correctly placed this source in the hottest part of the star - its center and assumed that a long time of diffusion of energy (millions of years) would level out all changes except those that appear near the surface. Eddington did not imagine the source this energy, but quite correctly placed this source in the hottest part of the star - its center and assumed that a long time of energy diffusion (millions of years) would level out all changes except those that appear near the surface.
Internal structure of stars Models of the structure of stars Equilibrium imposes strict restrictions on a star, i.e., having reached a state of equilibrium, the star will have a strictly defined structure. At each point of the star, a balance of gravitational forces, thermal pressure, radiation pressure, etc. must be maintained. Also, the temperature gradient must be such that the heat flow outward strictly corresponds to the observed radiation flow from the surface. Equilibrium imposes strict restrictions on the star, i.e., when in a state of equilibrium, the star will have a strictly defined structure. At each point of the star, a balance of gravitational forces, thermal pressure, radiation pressure, etc. must be maintained. Also, the temperature gradient must be such that the heat flow outward strictly corresponds to the observed radiation flow from the surface. All these conditions can be written in the form mathematical equations(at least 7), the solution of which is possible only by numerical methods. All these conditions can be written in the form of mathematical equations (at least 7), the solution of which is possible only by numerical methods.
Internal structure of stars Models of the structure of stars Mechanical (hydrostatic) equilibrium The force caused by the pressure difference, directed from the center, must be equal to the gravitational force. d P/d r = M(r)G/r 2, where P is pressure, is density, M(r) is mass within a sphere of radius r. Energy equilibrium The increase in luminosity due to the energy source contained in a layer of thickness dr at a distance from the center r is calculated by the formula dL/dr = 4 r 2 (r), where L is luminosity, (r) is the specific energy release of nuclear reactions. Thermal equilibrium The temperature difference at the inner and outer boundaries of the layer must be constant, and the inner layers must be hotter.
Internal structure of stars 1. Star core (zone of thermonuclear reactions). 2. Zone of radiative transfer of energy released in the core to the outer layers of the star. 3. Convection zone (convective mixing of matter). 4. Helium isothermal core made of degenerate electron gas. 5. Shell of ideal gas.
Internal structure of stars The structure of stars up to solar mass Stars with a mass less than 0.3 solar are completely convective, which is due to their low temperatures and high absorption coefficients. Stars with a mass less than 0.3 solar are completely convective, which is due to their low temperatures and high absorption coefficients. Solar mass stars undergo radiative transport in the core, while convective transport occurs in the outer layers. Solar mass stars undergo radiative transport in the core, while convective transport occurs in the outer layers. Moreover, the mass of the convective shell quickly decreases when moving up the main sequence. Moreover, the mass of the convective shell quickly decreases when moving up the main sequence.
Internal structure of stars Structure of degenerate stars Pressure in white dwarfs reaches hundreds of kilograms per cubic centimeter, and in pulsars it is several orders of magnitude higher. Pressure in white dwarfs reaches hundreds of kilograms per cubic centimeter, and in pulsars it is several orders of magnitude higher. At such densities, the behavior differs sharply from that of an ideal gas. The Mendeleev-Clapeyron gas law ceases to apply - pressure no longer depends on temperature, but is determined only by density. This is a state of degenerate matter. At such densities, the behavior differs sharply from the behavior of an ideal gas. The Mendeleev-Clapeyron gas law ceases to apply - pressure no longer depends on temperature, but is determined only by density. This is a state of degenerate matter. The behavior of a degenerate gas consisting of electrons, protons and neutrons obeys quantum laws, in particular the Pauli exclusion principle. He argues that no more than two particles can be in the same state, and their spins are in opposite directions. The behavior of a degenerate gas consisting of electrons, protons and neutrons obeys quantum laws, in particular the Pauli exclusion principle. He claims that no more than two particles can be in the same state, and their spins are in opposite directions. For white dwarfs, the number of these possible states is limited; gravity tries to squeeze electrons into already occupied spaces. In this case, a specific counter-pressure force arises. In this case, p ~ 5/3. For white dwarfs, the number of these possible states is limited; gravity tries to squeeze electrons into already occupied spaces. In this case, a specific counter-pressure force arises. In this case, p ~ 5/3. At the same time, electrons have high speeds of movement, and the degenerate gas has high transparency due to the occupation of all possible energy levels and the impossibility of the absorption-re-emission process. At the same time, electrons have high speeds of movement, and the degenerate gas has high transparency due to the occupation of all possible energy levels and impossibility of the absorption-re-emission process.
Internal structure of stars The structure of a neutron star At densities above g/cm 3, the process of neutronization of matter occurs, the reaction + e n + At densities above g/cm 3, the process of neutronization of matter occurs, the reaction + e n + In 1934, Fritz Zwicky and Walter Baarde theoretically predicted the existence of neutron stars, the equilibrium of which is maintained by the pressure of the neutron gas. In 1934, Fritz Zwicky and Walter Baarde theoretically predicted the existence of neutron stars, the equilibrium of which is maintained by the pressure of the neutron gas. The mass of a neutron star cannot be less than 0.1M and more than 3M. The density in the center of a neutron star reaches values of g/cm 3. The temperature in the interior of such a star is measured in hundreds of millions of degrees. The sizes of neutron stars do not exceed tens of kilometers. The magnetic field on the surface of neutron stars (millions of times greater than the Earth's) is a source of radio emission. The mass of a neutron star cannot be less than 0.1M and more than 3M. The density in the center of a neutron star reaches values of g/cm 3. The temperature in the interior of such a star is measured in hundreds of millions of degrees. The sizes of neutron stars do not exceed tens of kilometers. The magnetic field on the surface of neutron stars (millions of times greater than the Earth's) is a source of radio emission. On the surface of a neutron star, matter should have the properties solid, i.e., neutron stars are surrounded by a solid crust several hundred meters thick. On the surface of a neutron star, the substance must have the properties of a solid body, i.e., neutron stars are surrounded by a solid crust several hundred meters thick.
M. Dagaev and others. Astronomy - M.: Education, 1983 M. Dagaev and others. Astronomy - M.: Education, 1983 P.G. Kulikovsky. Handbook for an Astronomy Amateur - M.URSS, 2002 P.G. Kulikovsky. Handbook for an Astronomy Amateur - M.URSS, 2002 M.M.Dagaev, V.M.Charugin Astrophysics. Reading book on astronomy - M.: Prosveshchenie, 1988. M.M. Dagaev, V.M. Charugin Astrophysics. Reading book on astronomy - M.: Prosveshchenie, 1988. A.I. Eremeeva, F.A. Tsitsin “History of Astronomy” - M.: Moscow State University, 1989 A.I. Eremeeva, F.A. Tsitsin “History of Astronomy” - M.: MSU, 1989 W. Cooper, E. Walker “Measuring the light of stars” - M.: Mir, 1994 W. Cooper, E. Walker “Measuring the light of stars” - M. :World, 1994. R. Kippenhan. 100 billion suns. Birth, life and death of stars. M.: Mir, 1990 R. Kippenhan. 100 billion suns. Birth, life and death of stars. M.:Mir, 1990. Internal structure of stars References
Presentation on the topic: “Internal structure of the sun” Completed by a student of class 11 “a” GBOU secondary school 1924 Governors Anton
Internal structure of the Sun.
The sun is the only star solar system, around which other objects of this system revolve: planets and their satellites, dwarf planets and their satellites, asteroids, meteoroids, comets and cosmic dust.
Structure of the Sun: -Solar core. -Zone of radiative transfer. - Convective zone of the Sun.
Solar core. The central part of the Sun with a radius of approximately 150,000 kilometers, in which thermonuclear reactions occur, is called the solar core. The density of the substance in the core is approximately 150,000 kg/m³ (150 times higher than the density of water and ~6.6 times higher than the density of the densest metal on Earth - osmium), and the temperature in the center of the core is more than 14 million degrees.
Radiative transfer zone. Above the core, at distances of about 0.2-0.7 solar radii from its center, there is a radiative transfer zone in which there are no macroscopic movements; energy is transferred using photon re-emission.
Convective zone of the Sun. Closer to the surface of the Sun, vortex mixing of the plasma occurs, and the transfer of energy to the surface is accomplished primarily by the movements of the substance itself. This method of energy transfer is called convection, and the subsurface layer of the Sun, approximately 200,000 km thick, where it occurs is called the convective zone. According to modern data, its role in the physics of solar processes is exceptionally great, since it is in it that various movements of solar matter and magnetic fields originate.
Atmosphere of the Sun: -Photosphere. -Chromosphere. -Crown. -Solar wind.
Photosphere of the Sun. The photosphere (the layer that emits light) forms the visible surface of the Sun, from which the size of the Sun, the distance from the surface of the Sun, etc. are determined. The temperature in the photosphere reaches an average of 5800 K. Here, the average gas density is less than 1/1000 of the density of the earth's air.
Chromosphere of the Sun. The chromosphere is the outer shell of the Sun, about 10,000 km thick, surrounding the photosphere. The origin of the name of this part of the solar atmosphere is associated with its reddish color. The upper boundary of the chromosphere does not have a distinct smooth surface; hot emissions called spicules constantly occur from it. The temperature of the chromosphere increases with altitude from 4000 to 15,000 degrees.
Crown of the Sun. The corona is the last outer shell of the Sun. Despite its very high temperature, from 600,000 to 5,000,000 degrees, it is visible to the naked eye only during a total solar eclipse.
Solar Wind. Many natural phenomena on Earth are associated with disturbances in the solar wind, including geomagnetic storms and auroras.