Cognitive and research project in the senior group “What kind of sun is it? Project work on the topic: “The sun is a source of light and heat” Project on the topic of what the sun is made of.
About 4.5 billion years ago, no planets existed. A dark cloud of hot gas and dust seethed around the newly born Sun. Gradually the cloud cooled, and the gas condensed into millions of droplets. These drops were slowly attracted to each other under the influence of their own gravity - this is how the planets of the solar system gradually formed. The solar system includes 9 planets: Pluto, Neptune, Uranus, Saturn, Jupiter, Mars, Earth, Venus and Mercury.
The sun is an ordinary star, of which there are many in the Universe. It was formed from gas remaining after the explosion of a larger star at this site. Now, at the time of its maturity, the Sun emits a fairly even yellow light and constantly gives the Earth warmth. But it also emits deadly gamma, x-ray, infrared, ultraviolet rays, and radio waves. Fortunately, the Earth's atmosphere and magnetic field reliably protect people from these harmful radiations.
The Sun is a medium-sized star with a diameter of 1,392,000 km. It weighs a little less than 2000 trillion trillion tons. On the surface of the Sun, the temperature reaches an unimaginable value of 6000 degrees, at which any substance melts. But the core of the Sun is thousands of times hotter - more than 16 million degrees.
Solar heat is released as a result of nuclear reactions. Inside the Sun, enormous pressure forces the nuclei of hydrogen atoms to combine to form helium atoms. This releases gigantic amounts of nuclear energy.
The Sun is now in the middle of its life. Presumably it formed about 5 billion ice years ago. Apparently it will glow for another 5 billion years and then explode so brightly that it will burn the Earth to the ground.
Sometimes giant formations appear in the atmosphere of the Sun - eruptive prominences. They look like arches rising from the photosphere to a height of up to half the solar radius. Observations clearly indicate that the shape of prominences is determined by magnetic field lines. Another interesting and extremely active phenomenon is solar flares, powerful bursts of energy and particles lasting up to two hours. The flow of photons generated by such a solar flare reaches the Earth at the speed of light in 8 minutes, and the flow of electrons and protons - in several days. Solar flares occur in places where there is a sharp change in the direction of the magnetic field, caused by the movement of matter in sunspots.
The maximum of solar flare activity usually occurs a year before the maximum of the sunspot cycle. Such predictability is very important, because a barrage of charged particles generated by a powerful solar flare can damage even ground-based communications and energy networks, not to mention astronauts and space technology.
From the plasma corona of the Sun there is a constant outflow of charged particles emitted by the Sun at a speed of hundreds of kilometers per second, called the solar wind. The Earth's magnetic field protects people from it, but at the poles it interacts with the atmosphere, causing the northern lights and lightning.
Solar system, a system of celestial bodies (the Sun, planets, satellites of planets, comets, meteoroids, cosmic dust) moving in the region of the predominant gravitational influence of the Sun. The observed dimensions of the Solar System are determined by the orbit of Pluto. However, the sphere within which stable motion of celestial bodies around the Sun is possible extends almost to the nearest stars. Information about the distant outer region of the Solar System is obtained from observations of long-period comets approaching the Sun and from the study of cosmic dust filling the entire Solar System. General structure The solar system was discovered by N. Copernicus (mid-16th century), who substantiated the idea of the Earth’s movement, etc. planets around the Sun. Copernicus's heliocentric system made it possible for the first time to determine the relative distances of the planets from the Sun, and therefore from the Earth. J. Kepler discovered (early 17th century) the laws of planetary motion, and I. Newton formulated (late 17th century) the law of universal gravitation. These laws formed the basis of celestial mechanics, which studies the movement of bodies in the Solar System. The study of the physical characteristics of cosmic bodies included in the Solar System became possible only after the invention of the telescope by G. Galileo: in 1609 Galileo first directed the small telescope he had made to the Moon, Venus, Jupiter and Saturn made a number of discoveries that were amazing for his era. Observing sunspots, Galileo discovered the rotation of the Sun around its axis.
According to their physical characteristics, large planets are divided into internal (Mercury, Venus, Earth, Mars) and external giant planets (Jupiter, Saturn, Uranus, Neptune). The physical characteristics of Pluto are qualitatively different from the characteristics of the giant planets, and therefore it cannot be classified among them. An extensive observation program carried out in 1963 by the American astronomer C. Tombaugh to search for planets beyond the orbit of Pluto did not produce positive results. In table the osculating elements of the major planets are given (according to Osterwinter and Cohen, USA, 1972). The orbits of the major planets are slightly inclined to each other and to the fundamental plane of the Solar System (the so-called Laplace plane).
At the moment, the study of the solar system continues and it is unknown what surprises it will bring us in the future.
Municipal government agency:
"School-gymnasium No. 1 named after M. Gorky"
Project work on the topic:
"The sun is a source of light and heat"
Completed by a student of class 4 “A”: Nazarov D.
Head: Kenzhebekova L.T.
2016-2017 academic year
Project on the topic:
"A Star Called the Sun"
Performed:
Teacher of mathematics and physics:
Mekerova Fatima Magometovna
MCOU "Secondary School a. Psauchye-Dakhe
named after Hero of Russia O.M. Kardanova"
a.Psauchye-Dakhe
Page |
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I.1 Rationale for selection | |
I.2 Objectives of the work | |
I.3 Objectives of the work | |
I.4 Work steps | |
I.5 Required resources | |
I.6 Literature review | |
II.1 Introduction | |
II.2 General information about the Sun | |
III. Radiation from the Sun is the main source of energy on Earth | |
IV. Structure of the Sun | |
IV.1 Prominences | |
V. Visible part of the solar spectrum. | |
VI. Black body radiation. | |
VII. Position of the Sun in the Galaxy | |
VIII. Solar eclipse | |
VIII.1 Nature of a Solar Eclipse | |
VIII.2 Development of a Solar Eclipse | |
VIII.3 Features of observing a solar eclipse | |
VIII.4 Solar eclipses in the history of mankind | |
VIII.5 Astronomical classification of solar eclipses | |
IX. Origin and types of solar magnetic fields | |
X. | |
XI. Solar Neutrino Problem | |
XII. Corona heating problem | |
XIII. Observations of the Sun and danger to vision | |
XIV. Sun and Earth | |
XV. The sun in world religion | |
XVI. The sun in the languages of the world | |
XVII. Conclusion |
I .1 Justification for choice
The sun is the main source of life, heat and light on earth. In this regard, I became interested in this star, its properties and structure. I want to dedicate my project to a star named the Sun.
I .2 Objectives of the work
Find out as much information as possible about the Sun.
Draw appropriate conclusions.
I .3 Job objectives
Collect material.
Analyze the collected information.
Prepare the material.
Present research results.
I .4 Work steps
Stages of work |
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Planning |
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Collection of literature |
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Consultations with a physics teacher |
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Information analysis, design |
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Consultation with physics teachers on conducting |
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Development and delivery of classes |
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Analysis of collected material |
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Registration of work |
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Preparing a presentation for defense |
I .5 Required resources
Technical equipment: computer, Internet access, printer;
Software: publishing programs;
Internet resources: a list of web addresses needed to find information.
Other: who to invite, involve in work (Russian language teacher).
Methods used:
Literature analysis
I .6 Literature review
In the process of work, I studied a lot of interesting and useful literature. Using materials from books and articles, I became acquainted with the basic concepts of the Sun and its structure. Based on various films and video clips, I learned what the Sun is. Photos for the presentation were taken from various sites to help more clearly express the main ideas.
II.1. Introduction
Sun - the central and only star of the 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. The mass of the Sun is 99.8% of the total mass of the entire solar system. Solar radiation supports life on Earth (photons are necessary for the initial stages of the photosynthesis process) and determines climate. The sun consists of hydrogen (~73% of mass and ~92% of volume), helium (~25% of mass and ~7% of volume) and the following elements included in its composition in small concentrations: iron, nickel, oxygen , nitrogen, silicon, sulfur, magnesium, carbon, neon, calcium and chromium. According to the spectral classification, the Sun belongs to the G2V type (“yellow dwarf”). The surface temperature of the Sun reaches 6000 K, so the Sun shines with almost white light, but due to stronger scattering and absorption of the short-wave part of the spectrum by the Earth's atmosphere, the direct light of the Sun at the surface of our planet acquires a certain yellow tint.
The Sun belongs to the first type of stellar population. One of the common theories of the origin of the solar system suggests that its formation was caused by the explosions of one or more supernovae. This assumption is based, in particular, on the fact that the matter of the Solar System contains an anomalously large proportion of gold and uranium, which could be the result of endothermic reactions caused by this explosion, or the nuclear transformation of elements by absorption of neutrons by the matter of a massive second-generation star.
The radius of the Sun is 109 times greater than the radius of the Earth. The size of the Sun is very large. Thus, the radius of the Sun is 109 times, and its mass is 330,000 times greater than the radius and mass of the Earth. But the average density of our star is small - only 1.4 times the density of water. For the first time, Galileo observed the rotation of the Sun from the movement of spots on the surface. Different zones of the Sun rotate around an axis with different periods. So points on the equator have a period of about 25 days, at a latitude of 40° the rotation period is 27 days, and near the poles - 30 days. This proves that the Sun does not rotate like a rigid body; the speed of rotation of points on the surface of the Sun decreases from the equator to the poles. The total amount of energy emitted by the Sun is L = 3.86∙1033 erg/s = 3.86∙1026 W. This corresponds to 6.5 kW from every square centimeter of its surface! Only one two-billionth of this energy is received by the Earth.
On 1 square meter of the surface of the site in the vicinity of the Earth facing the Sun, 1400 J of energy transferred by solar electromagnetic radiation are received every second. This value is called the solar constant. In other words, the solar radiation energy flux density is 1.4 kW/m2.
II.2 General information about the Sun:
Weight - 1.990 10 30 kg (332,958 times the mass of the Earth).
Radius - 696,000 km
Average density - 1,400 kg/m3
Average distance from Earth - 149.6 million km
Rotation period - 25.380 days
Apparent magnitude –26.75m
Spectral class - G2 V
Effective surface temperature - 5,780 K
Age - about 5 billion years
diameter - approximately 1,392,000 km (109 times the diameter of the Earth),
the average density of matter in the sun is 1.4 g/cm3,
average surface temperature - more than 5500 K,
The core temperature reaches 15 million K.
III. Radiation from the Sun is the main source of energy on Earth.
Its power is characterized by the solar constant - the amount of energy passing through a unit area area perpendicular to the sun's rays. At a distance of one astronomical unit (that is, in Earth's orbit), this constant is approximately 1370 W/m².
The sun emits energy equivalent to 517,000 trillion horsepower every second. The Sun emits this colossal energy for at least three billion years (the lifetime of the Earth). No matter how great this radiation from the Sun is, there are stars that emit even more energy.
The star 8 Dorado in the southern hemisphere (invisible to the naked eye) emits a million times more energy. The most important and difficult question is how these wasteful expenditures of energy can be replenished.
The source of energy cannot be the phenomena of combustion, nor the energy obtained from the fall of meteorites, nor the energy obtained from the compression of stars, nor radioactive energy - all these sources are too insignificant to replenish these expenses over a long time. Only the energy released during the formation of complex elements, so-called nuclear reactions inside the atom, can explain this radiation from stars over many billions of years. In particular, the energy of the Sun is generated due to the reaction of the transition of hydrogen into helium, this is the so-called carbon cycle, in which carbon is a catalyst.
Passing through the Earth's atmosphere, solar radiation loses approximately 370 W/m² in energy, and only 1000 W/m² reaches the earth's surface (in clear weather and when the Sun is at its zenith). This energy can be used in various natural and artificial processes. Thus, plants process it into chemical form (oxygen and organic compounds) using photosynthesis. Direct heating by the sun's rays or energy conversion using photocells can be used to generate electricity (solar power plants) or perform other useful work. In the distant past, energy stored in oil and other types of fossil fuels was also obtained through photosynthesis. Ultraviolet radiation from the sun has antiseptic properties, allowing it to be used to disinfect water and various objects.
It also causes tanning and has other biological effects, such as stimulating the body's production of vitamin D.
The effect of the ultraviolet part of the solar spectrum is greatly attenuated by the ozone layer in the Earth's atmosphere, so the intensity of ultraviolet radiation at the Earth's surface varies greatly with latitude. The angle at which the Sun stands above the horizon at noon affects many types of biological adaptation - for example, it affects the color of human skin in different regions of the globe.
The path of the Sun across the celestial sphere observed from Earth changes throughout the year. The path described during the year by the point occupied by the Sun in the sky at a certain given time is called analemma and has the shape of a number 8, elongated along the north-south axis. The most noticeable variation in the apparent position of the Sun in the sky is its oscillation along the north-south direction with an amplitude of 47° (caused by the inclination of the ecliptic plane to the plane of the celestial equator, equal to 23.5°). There is also another component of this variation, directed along the east-west axis and caused by an increase in the speed of the Earth's orbital motion as it approaches perihelion and a decrease as it approaches aphelion. The first of these movements (north - south) is the reason for the change of seasons. The Earth passes through the aphelion point in early July and moves away from the Sun at a distance of 152 million km, and through the perihelion point in early January and approaches the Sun at a distance of 147 million km . The apparent diameter of the Sun changes by 3% between these two dates. Since the difference in distance is approximately 5 million km, at aphelion the Earth receives approximately 7% less heat. Thus, winters in the northern hemisphere are slightly warmer than in the southern hemisphere, and summers are slightly cooler.
The Sun is a magnetically active star. It has a strong magnetic field, the strength of which varies over time and which changes direction approximately every 11 years during solar maximum. Variations in the magnetic field of the Sun cause a variety of effects, the totality of which is called solar activity and includes such phenomena as sunspots, solar flares, variations in the solar wind, etc., and on Earth causes auroras in high and middle latitudes and geomagnetic storms , which negatively affect the operation of communications, means of transmitting electricity, and also negatively affects living organisms (cause headaches and poor health in people sensitive to magnetic storms). It is assumed that solar activity played a large role in the formation and development of the Solar System. It also influences the structure of the earth's atmosphere.
IV. Structure of the Sun
Internal structure Sun layered, or shell-like, it consists of a number of spheres, or regions. In the center is the core, then the region of radial energy transfer, then the convective zone and, finally, the atmosphere. A number of researchers include three external regions: the photosphere, the chromosphere and the corona. True, other astronomers consider only the chromosphere and corona to be the solar atmosphere. Let us briefly dwell on the features of these areas.
Core
- the central part of the Sun with ultra-high pressure and temperature, ensuring the flow of nuclear reactions. They release enormous amounts of electromagnetic energy in extremely short wavelength ranges.
Region of radiative energy transfer-located above the nucleus. It is formed by practically motionless and invisible ultra-high-temperature gas. The energy generated in the core is transferred through it to the outer spheres of the Sun by beam method, without moving gas. This process should be imagined something like this.
From the core to the region of radiation transfer, energy enters in extremely short-wave ranges - gamma radiation, and leaves in longer-wave x-rays, which is associated with a decrease in gas temperature towards the peripheral zone.
Convective region
- located above the previous one. It is also formed by invisible hot gas in a state of convective mixing. Mixing is caused by the position of the region between two environments that differ sharply in the pressure and temperature prevailing in them. The transfer of heat from the solar interior to the surface occurs as a result of local uplifts of highly heated air masses under high pressure to the periphery of the star, where the temperature of the gas is lower and where the light range of the Sun's radiation begins. The thickness of the convective region is estimated to be approximately 1/10 of the solar radius.
Photosphere
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it is the lowest of the three layers of the Sun's atmosphere, located directly on a dense mass of invisible gas in the convective region. The photosphere is formed by hot ionized gas, the temperature of which at the base is close to 10,000 K (i.e. absolute temperature), and at the upper boundary, located approximately 300 km above, is about 5,000 K. The average temperature of the photosphere is taken to be 5,700 K. At this temperature hot gas emits electromagnetic energy predominantly in the optical wavelength range.
It is this lower layer of the atmosphere, visible as a yellowish-bright disk, that is visually perceived by us as the Sun.
Through the transparent air of the photosphere, its base is clearly visible through the telescope - contact with the mass of opaque air of the convective region. The interface has a granular structure called granulation. Grains, or granules, have diameters from 700 to 2000 km.
The position, configuration and size of the granules change. Observations have shown that each granule individually is expressed only for a short time (about 5-10 minutes), and then disappears, being replaced by a new granule.
On the surface of the Sun, granules do not remain motionless, but make irregular movements at a speed of approximately 2 km/sec. Collectively, light grains (granules) occupy up to 40% of the surface of the solar disk.
The granulation process is represented as the presence in the lowest layer of the photosphere of opaque gas of the convective region - a complex system of vertical circulations.
A bright cell is a portion of gas arriving from the depths that is more heated than that already cooled on the surface, and therefore less bright, compensatingly sinking down. The brightness of the granules is 10-20% greater than the surrounding background, indicating a difference in their temperatures of 200-300° C.
Figuratively, granulation on the surface of the Sun can be compared to the boiling of a thick liquid such as molten tar, when air bubbles appear with light ascending jets, and darker and flatter areas characterize submerging portions of the liquid.
Studies of the mechanism of energy transfer in the solar gas ball from the central region to the surface and its radiation into outer space have shown that it is transferred by rays. Even in the convective zone, where energy is transferred by the movement of gases, most of the energy is transferred by radiation.
Thus, the surface of the Sun, emitting energy into outer space in the light range of the spectrum of electromagnetic waves, is a rarefied layer of gases of the photosphere and the granular upper surface of the layer of opaque gas of the convective region visible through it. In general, the granular structure, or granulation, is recognized as characteristic of the photosphere - the lower layer of the solar atmosphere.
Chromosphere.
During a total solar eclipse, a pink glow is visible at the very edge of the darkened disk of the Sun - this is the chromosphere. It does not have sharp boundaries, but is a combination of many bright protrusions or flames that are in continuous movement. The chromosphere is sometimes compared to a burning steppe. The tongues of the chromosphere are called spicules. They range from 200 to 2000 km in diameter (sometimes up to 10,000) and reach a height of several thousand kilometers.
They should be imagined as streams of plasma (hot ionized gas) escaping from the Sun.
It has been established that the transition from the photosphere to the chromosphere is accompanied by an abrupt increase in temperature from 5700 K to 8000 - 10000 K. To the upper boundary of the chromosphere, located approximately at an altitude of 14000 km from the surface of the sun, the temperature rises to 15000 - 20000 K. The density of matter at such altitudes is only 10-12 g/cm3, i.e. hundreds and even thousands of times less than the density of the lower layers of the chromosphere.
Solar corona
- the outer atmosphere of the Sun. Some astronomers call it the atmosphere of the Sun. It is formed by the most rarefied ionized gas. It extends approximately to a distance of 5 solar diameters, has a radiant structure, and glows faintly. It can only be observed during a total solar eclipse. The brightness of the corona is about the same as that of the Moon at full moon, which is only about 5/1,000,000th of the brightness of the Sun. Coronal gases are highly ionized, which determines their temperature to be approximately 1 million degrees. The outer layers of the corona emit coronal gas - the solar wind - into outer space. This is the second energy flow (after the radiant electromagnetic one) from the Sun received by the planets. The speed of removal of coronal gas from the Sun increases from several kilometers per second at the corona to 450 km/sec at the level of the Earth's orbit, which is associated with a decrease in the gravitational force of the Sun with increasing distance.
Gradually thinning out as it moves away from the Sun, coronal gas fills all interplanetary space. It affects the bodies of the solar system both directly and through the magnetic field that it carries with it. It interacts with the magnetic fields of the planets. It is the coronal gas (solar wind) that is the main cause of auroras on Earth and the activity of other processes in the magnetosphere.
IV. 1 Prominences- dense condensations of relatively cold (compared to the solar corona) matter that rise and are held above the surface of the Sun by a magnetic field.
Prominences are distinguished by a fibrous and clumpy structure of constantly moving filaments and plasma clots and a variety of forms, classified either by morphological or dynamic characteristics.
Based on the type of prominence, the speed and characteristics of the movement of matter in it, it can be classified into one of the following classes:
Calm - the movements of matter and the change in shape in them are slow; lifetime of weeks and even months; observed at all heliographic latitudes. They appear either far from groups of sunspots or close to them in the later stages of their development. Kinetic temperature - 15000°.
Active - in them there are fairly rapid movements of flows of matter from the prominence to the photosphere, from one prominence to another. Many quiet prominences also experience an active stage, lasting from tens of minutes to several days, ending with either complete disappearance or its transformation into an eruptive prominence. Kinetic temperature - 25000°.
Eruptive, or eruptive, resemble huge fountains in appearance, reaching heights of up to 1.7 million km above the surface of the Sun. The movements of clots of matter in them occur quickly; erupt at speeds of hundreds of km/sec and change their shape quite quickly. As the altitude increases, the prominence weakens and dissipates. In some prominences, sharp changes in the speed of movement of individual clumps were observed. Eruptive prominences are short-lived.
Coronal, or loop-shaped- appear above the chromosphere in the form of small clouds, which then merge into one cloud, from which streams of luminous matter descend in separate jets down to the chromosphere. The whole phenomenon lasts several hours. Large prominences and energetic coronal ejections are quite rare, occurring much more often near the maximum of the 11-year solar activity cycle, when many sunspots and other active phenomena are observed.
The following classification of prominences, taking into account the nature of the movement of matter in them and the shape of the prominences:
Type I (rare) has the form of a cloud or a stream of smoke. Development begins from the base and the substance rises in a spiral to great heights. The speed of matter can reach 700 km/sec. At an altitude of about 100 thousand km, pieces separate from the prominence, then fall back along trajectories resembling magnetic field lines.
Type II has the form of curved jets that begin and end on the surface of the Sun. Nodes and jets move as if along magnetic lines of force. The speed of movement of the clumps is from several tens to 100 km/sec. At altitudes of several hundred thousand km, the jets and clumps fade away.
Type III has the form of a bush or tree; reaches very large sizes. The movements of the clumps (up to tens of km/sec) are disordered.
V.Visible part of the solar spectrum.
The continuous spectrum has the highest intensity in the wavelength range 430–500 nm. In the visible and infrared regions, the spectrum of electromagnetic radiation from the Sun is close to the spectrum of radiation from an absolutely black body with a temperature of 6000 K. This temperature corresponds to the temperature of the visible surface of the Sun - the photosphere. In the visible region of the solar spectrum, the most intense are the H and K lines of ionized calcium, the lines of the Balmer series of hydrogen Hα, Hβ and Hγ. About 9% of the energy in the solar spectrum comes from ultraviolet radiation with wavelengths from 100 to 400 nm.
The remaining energy is divided approximately equally between the visible (400–760 nm) and infrared (760–5000 nm) regions of the spectrum.
For the first time, the method of measuring the heating effect of solar rays was used to determine solar energy (1837). Such a device is called pyrheliometer. The pyrheliometer contained water, the temperature of which was measured by an ordinary thermometer. Under the influence of sunlight, the water temperature increased.
The spectrum of the Sun is continuous, it contains many dark C:\Users\User\AppData\work\ÑолнÑе\DswMedia\ Fraunhofer lines. Fraunhofer was the first to describe dark lines against a continuous spectrum in 1814.
These lines in the solar spectrum are formed as a result of the absorption of light quanta in the colder layers of the solar atmosphere.
VI. Black body radiation.
The sun is a powerful source of radio emission. Radio waves penetrate into interplanetary space and are emitted by the chromosphere (centimeter waves) and the corona (decimeter and meter waves). Radio emission from the Sun has two components - constant and variable. The constant component characterizes the radio emission of the quiet Sun. The solar corona emits radio waves as a completely black body with a temperature T = 106 K. The variable component of radio emission from the Sun manifests itself in the form of bursts and noise storms. Noise storms last from several hours to several days. 10 minutes after a strong solar flare, the radio emission from the Sun increases thousands and even millions of times compared to the radio emission from the quiet Sun; this state lasts from several minutes to several hours. This radio emission is non-thermal in nature.
The solar radiation flux density in the X-ray region (0.1–10 nm) is very small (~5∙10–4 W/m2) and varies greatly with changes in the level of solar activity. In the ultraviolet region at wavelengths from 200 to 400 nm, the spectrum of the Sun is also described by the laws of black body radiation.
In the ultraviolet region of the spectrum with wavelengths shorter than 200 nm, the intensity of the continuous spectrum drops sharply and emission lines appear. The most intense of them is the hydrogen line of the Lyman series (λ = 121.5 nm). With a width of this line of about 0.1 nm, it corresponds to a radiation flux density of about 5∙10–3 W/m2. The radiation intensity in the line is approximately 100 times less. Bright emission lines of various atoms are also noticeable; the most important lines belong to Si I (λ = 181 nm), Mg II and Mg I, O II, O III, C III and others. Short-wave ultraviolet radiation from the Sun occurs near the photosphere.
X-ray radiation comes from the chromosphere (T ~ 104 K), located above the photosphere, and the corona (T ~ 106 K), the outer shell of the Sun. Radio emission at meter waves occurs in the corona, and at centimeter waves - in the chromosphere.
VII. Position of the Sun in the Galaxy
The first person to notice that in the direction of the constellation Hercules the stars seem to diverge in different directions, and on the opposite side they seem to move, was William Herschel. He explained this by the movement of the Sun in space. The Sun (and the Solar System) is moving at a speed of 20 km/s towards the border of the constellations Lyra and Hercules. This is explained by local motion within nearby stars. This point is called the apex of the Sun's movement, its coordinates are α ≈ 18h, δ ≈ +30°. The point on the celestial sphere opposite the apex is called antiapex. At this point the directions of the natural velocities of the stars closest to the Sun intersect. The movements of the stars closest to the Sun occur at low speed; this does not prevent them from participating in orbit around the galactic center. The solar system is involved in rotation around the center of the Galaxy at a speed of about 220 km/s. This movement occurs in the direction of the constellation Cygnus. The period of revolution of the Sun around the galactic center is about 220 million years.
VIII.Solar eclipse
Solar eclipse- an astronomical phenomenon, which consists in the fact that the Moon covers (eclipses) completely or partially the Sun from an observer on Earth. A solar eclipse is only possible during a new moon, when the side of the Moon facing the Earth is not illuminated and the Moon itself is not visible. Eclipses are only possible if the new moon occurs near one of the two lunar nodes (the point where the visible orbits of the Moon and the Sun intersect), no more than about 12 degrees from one of them. A total solar eclipse cannot last more than 8 minutes.
VIII.1 Nature of the Solar Eclipse
The Sun and Moon are the only celestial bodies in the earth's sky that have dimensions visible to the naked eye.
The Sun is a star with a diameter of 1,392,000 kilometers and a mass of 332,946 Earth masses. The surface temperature is 5,500°C, the temperature in the center is 15,500,000°C, the rotation period is 25 Earth days at the equator, 34 Earth days at the poles.
The Moon is the only natural satellite of the Earth. Located at a distance of 384,401 kilometers from Earth. Its diameter is 3,476 kilometers, its mass is 1.2% of the Earth's mass, and there is no atmosphere. The length of a day (the number of Earth days) – both sidereal and solar – is 29.5. The areas of the Moon illuminated by the Sun heat up to 117°C, those in the shadow cool down to -153°C.
The Earth moves around the Sun in one plane, and the Moon around the Earth in another, these planes do not coincide. The plane of the lunar orbit is inclined to the plane of the ecliptic by 5.2°, and the diameters of the solar and lunar disks are close to 0.5°. Therefore, often during new moons the Moon passes either above or below the Sun. The apparent path of the Moon in the sky does not coincide with the path along which the Sun moves. These paths intersect at two opposite points, which are called the nodes of the lunar orbit. Near these points, the paths of the Sun and Moon come close to each other. And only when the new moon occurs near a node is it accompanied by an eclipse. If at the new moon the Sun and the Moon are almost exactly at the node, the eclipse will be total or annular, and if the Sun at the time of the new moon is at some distance from the node, then the centers of the lunar and solar disks will not coincide and the Moon will only partially cover the Sun. Such an eclipse is called a partial eclipse. Solar eclipses are only possible during the new moon. The degree of occlusion is called the eclipse phase in astronomy.
Around the spot of the lunar shadow there is a region of penumbra, where a partial eclipse occurs. The diameter of the penumbra region is about 6-7 thousand km. For an observer located near the edge of this region, only a small fraction of the solar disk will be covered by the Moon, and the eclipse may go unnoticed altogether.
The shadow of the Moon moves relative to the Earth at a speed of 1 km/sec. The small size of the shadow and the high speed of its movement lead to the fact that the shadow cannot cover any one place on the globe for a long time.
Scientists have long established that after 6585 days 8 hours, which is 18 years 11 days 8 hours, eclipses are repeated. It is after this period of time that the location in space of the Moon, Earth and Sun is repeated.
However, saros does not contain an integer number of days, but 6585 days and 8 hours.
In the same place on Earth, a total solar eclipse is observed once every 250 - 300 years. Nowadays, eclipses are predicted very accurately. The error in predicting the moment of occurrence does not exceed 2 - 4 seconds.
In the last century, the longest duration of eclipses was in 1955 and 1973 (no more than 7 minutes). A total solar eclipse of almost the longest possible duration (7 minutes 29 seconds) will occur only on July 16, 2186 in the equatorial belt of the Earth. In exceptional cases, the longest duration of the annular phase of a solar eclipse reaches 12.3 minutes, and a partial eclipse - up to 3.5 hours. The vast majority of eclipses last up to two and a half hours, and their total or annular phase is only 2-3 minutes. The total duration of a total eclipse on Earth from the moment the lunar shadow enters our planet until the shadow leaves it usually ranges from one to three and a half hours. During this period of time, the lunar shadow travels along the Earth from 6,000 to 12,000 km. A solar eclipse begins in the western regions of the earth's surface at sunrise and ends in the east at sunset. The total duration of all phases of a solar eclipse on Earth can reach six hours.
During a solar eclipse, astronauts in orbit can observe the shadow of the Moon on the Earth's surface. Those on Earth who fall into this shadow observe a solar eclipse.
VIII.2 Development of a Solar Eclipse
First, a barely noticeable dark stripe appears on the western side of the sun. It is impossible to catch it with the naked eye. Soon the strip takes the form of a notch on the surface of the sun, gradually the sunlight decreases and the landscape around the observer becomes steel-colored.
Literally fifteen minutes before the onset of a total eclipse, the sky relative to the location of the sun in the west is darker than in the east. The shadow of the moon appears. The sky takes on a bluish-gray or purple color.
Five minutes before total eclipse, the darkness in the west becomes apparent, gaining strength and smoothly moving along the horizon, leaving behind a yellowish-orange twilight.
When the Moon almost completely covers the Sun (in a total solar eclipse), bright spots of sunlight flash near the edge of the Moon. This effect, known as Bailey's rosary, is named after Francis Bailey, who first noticed this phenomenon in 1836. The number and brightness of Bailey's beads are not always unpredictable, but their main features are quite expected. When one spot dominates, the phenomenon is called the diamond ring effect and is usually observed just before the full phase.
The edge of the incandescent globe of the sun glows like a jewel, and the solar corona glows around the dark lunar disk.
The solar corona is a dimly glowing halo formed by hot gas around the solar disk. Since this glow is weaker than the glow of the Sun, the corona is clearly visible only during solar eclipses, when the disk of the luminary is covered by the Moon.
The shape of the corona depends on the period of solar activity. During the minimum activity, the corona looks small and round, and in the years of maximum activity, the spread of the “ruffled” corona reaches several radii of the solar disk. During the full phase, prominences are visible at the edge of the disk, which look like small curving pink emissions.
Gradually it becomes lighter in the west, while in the east the darkness thickens and decreases towards the horizon.
VIII.3 Features of observing a solar eclipse
It is important to remember that outside of an eclipse or during partial phases of an eclipse, looking at the Sun without protecting your eyes with dark filters is strictly prohibited. This warning especially applies to observations of the Sun with optical instruments. Failure to follow these guidelines may cause immediate and permanent eye damage. Therefore, in front of the lens (lenses) of an optical instrument (binoculars, telescope, telescope), it is necessary to attach a dark filter of sufficient density so that the eyes do not feel irritated by sunlight. Even with a solar eclipse phase of 0.9, when the Moon covers 90% of the visible diameter of the Sun, 0.125 (one eighth) of the solar disk remains open, and sunlight is weakened by only 810 times, which is still dangerous for vision, especially since the exposed part has unattenuated surface brightness.
Any mechanical or electronic wristwatch with a second hand (numbers) or a stopwatch is suitable for recording moments in time. Clocks must be adjusted twice to radio time signals or television clocks, once before the partial eclipse begins and again after it ends.
You can photograph an eclipse by attaching a camera at the direct focus of the telescope, removing the eyepiece from the telescope, and attaching a camera without a lens in its place. For focusing, it is advisable to use SLR cameras.
Prominences are best viewed through a telescope with high magnification and automatic guiding.
During a total eclipse, it is also worth paying attention to the surrounding area. The dark purple sky will be streaked with reddish-orange across the horizon. This phenomenon is called a glow ring. This is how the sky glows in places where there is a partial eclipse, because the shadow of the Moon covers an area of the Earth with an average diameter of 150 kilometers, and the high layers of the atmosphere are visible for hundreds of kilometers. The glow ring is observed exclusively during total eclipses. Eclipse observers should also pay attention to the behavior of animals, which are sensitive to celestial phenomena, especially eclipses. In addition, it is recommended to record air temperature, wind direction and strength, and atmospheric pressure.
VIII .4 Solar eclipses in human history
This phenomenon has been known for a very long time. In ancient times, in the fading of the Sun in broad daylight, people saw the manifestation of unknown, supernatural forces.
The eastern peoples believed that at this time the Heavenly Dragon was devouring the Sun. In ancient China, during solar eclipses, residents, in order to drive away the dragon and free the Sun, beat drums, greeted the eclipse with the sounds of a gong, ringing bells, and sang prayers. It is interesting that in Turkey in 1877, during an eclipse, frightened residents fired guns at the Sun, wanting to drive away Shaitan - an evil spirit who, in their opinion, was devouring the Sun.
By the beginning of the 6th century. BC e. Ancient astronomers were able to establish the cause of solar eclipses. They paid attention to the covering of stars by the Moon as it moved across the sky and to the disappearance of the Moon during solar eclipses and came to the conclusion that the Moon meets the Sun and obscures it. Herodotus describes the famous naval battle of Salamis between the Greek and Persian fleets, which took place in the Saronic Gulf off the southern coast of Greece. This battle is famous for the fact that the Persian fleet of 800 ships was completely defeated by the Greek fleet of 350 ships. On this day, a total eclipse of the Sun occurred on the southern coast of Greece and the date of the battle was calculated from it - October 2, 480 BC.
At the beginning of the Peloponnesian War between the ancient Greek city-states of Athens and Sparta, a solar eclipse nearly disrupted the Athenian naval expedition commanded by the eminent strategist Pericles (c. 490-429 BC). Pericles was a student of the famous philosopher Anaxagoras (circa 500-428 BC) and therefore knew well the cause of solar eclipses. When the Athenian fleet was ready to sail, an eclipse of the Sun began. The ensuing darkness terrified the sailors and soldiers and was perceived by them as a bad omen. Seeing that the ship's pilot was in great confusion and completely unable to steer the ship, Pericles took his cloak, covered the pilot's eyes with it and asked him if he saw anything terrible or some kind of bad omen in this cloak. Having received a negative answer from the pilot, Pericles said to him: “So what then is the difference between this cloak and the body that covered the Sun, except that it is larger than my cloak!” The actions and words of Pericles calmed not only the pilot, but also the soldiers who were observing this scene, after which the fleet left the harbor in proper formation.
VIII .5 Astronomical classification of solar eclipses
According to astronomical classification, if an eclipse at least somewhere on the Earth's surface can be observed as total, it is called complete. If an eclipse can only be observed as a partial eclipse (this happens when coneshadowsMoon passes close to the earth's surface, but does not touch it), the eclipse is classified as private. When an observer is in the shadow of the Moon, he is observing a total solar eclipse. When he is in the area penumbra, he can observe a partial solar eclipse. In addition to total and partial solar eclipses, there are annular eclipses. An annular eclipse occurs when, at the time of the eclipse, the Moon is further away from the Earth than during a total eclipse, and the cone of the shadow passes over the Earth's surface without reaching it. Visually, during an annular eclipse, the Moon passes across the disk of the Sun, but it turns out to be smaller in diameter than the Sun, and cannot hide it completely. In the maximum phase of the eclipse, the Sun is covered by the Moon, but around the Moon a bright ring of the uncovered part of the solar disk is visible. During an annular eclipse, the sky remains bright, stars do not appear, and it is impossible to observe the solar corona. The same eclipse can be visible in different parts of the eclipse band as total or annular. Such an eclipse sometimes called full ring-shaped (or hybrid).
IX. Origin and types of solar magnetic fields
Because it's sunny plasma has a fairly high electrical conductivity, it may contain electric currents and as a consequence, magnetic fields. Magnetic fields directly observed in the solar photosphere are usually divided into two types, according to their scale.
Large scale ( general or global ) a magnetic field with characteristic dimensions comparable to the size of the Sun, has an average intensity at the photosphere level of the order of several gauss. At the minimum of the solar activity cycle it has approximately dipole structure, while the field strength at the poles of the Sun is maximum. Then, as the solar activity cycle approaches the maximum, the field strengths at the poles gradually decrease and one to two years after the cycle maximum become zero (the so-called “solar magnetic field reversal”).
At this phase, the general magnetic field of the Sun does not disappear completely, but its structure is not dipole, but quadrupole character. After this, the intensity of the solar dipole increases again, but at the same time it has a different polarity. Thus, the full cycle of changes in the general magnetic field of the Sun, taking into account the change in sign, is equal to twice the duration of the 11-year cycle of solar activity - approximately 22 years (“Hale’s law”).
Medium and small scale ( local ) fields Suns have significantly higher field strengths and less regularity. The most powerful magnetic fields (up to several thousand gauss) are observed in groups sunspots at maximum solar cycle. In this case, a typical situation is when the magnetic field of spots in the western (“head”) part of a given group, including the largest spot (the so-called “group leader”) coincides with the polarity of the general magnetic field at the corresponding pole of the Sun (“p- polarity"), and in the eastern (“tail”) part it is opposite to it (“f-polarity”). Thus, the magnetic fields of sunspots have, as a rule, a bipolar or multipolar structure.
In the photosphere, unipolar regions of the magnetic field are also observed, which, unlike groups of sunspots, are located closer to the poles and have a significantly lower magnetic field strength (several gauss), but a larger area and lifespan (up to several solar revolutions).
According to modern ideas, shared by most researchers, the Sun's magnetic field is generated in the lower part convective zone by mechanism hydromagnetic convective dynamo, and then floats up into the photosphere under the influence magnetic buoyancy. The same mechanism explains the 22-year cyclicity of the solar magnetic field.
X. Solar activity and solar cycle
The complex of phenomena caused by the generation of strong magnetic fields on the Sun is called solar activity . These fields appear in the photosphere as sunspots and cause phenomena such as solar flares, the generation of streams of accelerated particles, changes in the levels of electromagnetic radiation from the Sun in various ranges, coronal mass ejections, solar wind disturbances, variations in galactic cosmic ray fluxes (Forbush effect) etc.
Solar flare- an explosive process of energy release (light, heat and kinetic) in the solar atmosphere. Flares in one way or another cover all layers of the solar atmosphere: the photosphere, chromosphere and corona of the sun. It should be noted that solar flares and coronal mass ejections are different and independent phenomena of solar activity.
The duration of the pulse phase of solar flares usually does not exceed several minutes, and the amount of energy released during this time can reach billions of megatons of TNT equivalent. The flare energy is traditionally determined in the visible range of electromagnetic waves by the product of the glow area in the hydrogen emission line H α, which characterizes the heating of the lower chromosphere, and the brightness of this glow, associated with the power of the source. Solar flares tend to occur at interaction sites sunspots opposite magnetic polarity or, more precisely, near the neutral magnetic field line separating the regions of north and south polarity. The frequency and power of solar flares depend on the phase solar cycle.
Solar activity is also associated with variations in geomagnetic activity (including magnetic storms), which are a consequence of disturbances in the interplanetary medium reaching the Earth, caused, in turn, by active phenomena on the Sun.
One of the most common indicators of the level of solar activity is the Wolf number, which is associated with the number of sunspots on the visible hemisphere of the Sun.
The overall level of solar activity varies with a characteristic period of approximately 11 years (the so-called “solar activity cycle” or “eleven-year cycle”). This period is not precisely maintained and in the 20th century was closer to 10 years, and over the last 300 years it has varied from approximately 7 to 17 years. It is customary to assign sequential numbers to cycles of solar activity, starting from the conventionally selected first cycle, the maximum of which was in 1761. In 2000, the maximum of the 23rd cycle of solar activity was observed.
There are also variations in solar activity of longer duration. Thus, in the second half of the 17th century, solar activity and, in particular, its eleven-year cycle were greatly weakened (Maunder minimum). During the same era, a decrease in average annual temperatures was observed in Europe (the so-called Little Ice Age), which was possibly caused by the impact of solar activity on the Earth's climate. There is also a view that global warming is to some extent caused by an increase in global solar activity in the second half of the 20th century. However, the mechanisms of such an effect are not yet clear enough.
The largest group of sunspots on record occurred in April 1947 in the southern hemisphere of the Sun. Its maximum length was 300,000 km, its maximum width was 145,000 km, and its maximum area exceeded 6,000 parts per million of the hemispherical area (MPA) of the Sun, which is about 36 times the surface area of the Earth. The group was easily visible to the naked eye in the pre-sunset hours. According to the catalog of the Pulkovo Observatory, this group (No. 87 for 1947) passed through the hemisphere of the Sun visible from the Earth from March 31 to April 14, 1947, its maximum area was 6761 msh, and the maximum area of the largest spot in the group was 5055 msh; the number of spots in the group reached 172.
XI.Solar Neutrino Problem
Nuclear reactions occurring in the core of the Sun lead to the formation of a large number of electron neutrinos. At the same time, measurements of the neutrino flux on Earth, which have been continuously carried out since the late 1960s, have shown that the number of detected solar electron neutrinos is approximately two to three times less than predicted by the standard solar model, which describes processes in the Sun. This discrepancy between experiment and theory is called "solar neutrino problem" and for more than 30 years it was one of the mysteries of solar physics. The situation is complicated by the fact that neutrinos interact extremely weakly with matter, and the creation of a neutrino detector that can accurately measure the neutrino flux even of such power as that coming from the Sun is a technically complex and expensive task (see Neutrino astronomy).
Two main ways to solve the problem of solar neutrinos have been proposed. First, it was possible to modify the model of the Sun in such a way as to reduce the estimated thermonuclear activity (and, therefore, the temperature) in its core and, consequently, the flux of neutrinos emitted by the Sun. Secondly, it could be assumed that part of the electron neutrinos emitted by the solar core, when moving towards the Earth, turns into neutrinos of other generations (muon and tau neutrinos) that are not detected by conventional detectors. Today it is clear that the second path is most likely correct.
In order for a transition from one type of neutrino to another to take place - that is, so-called neutrino oscillations occur - the neutrino must have a non-zero mass. It has now been established that this is indeed the case. In 2001, at the Sudbury Neutrino Observatory ( English) all three types of solar neutrinos were directly detected, and their total flux was shown to be consistent with the standard solar model. At the same time, only about a third of neutrinos reaching the Earth turn out to be electrons. This quantity is consistent with the theory, which predicts the transition of electron neutrinos into neutrinos of another generation both in vacuum (actually “neutrino oscillations”) and in solar matter (“Mikheev-Smirnov-Wolfenstein effect”). Thus, the problem of solar neutrinos is now apparently solved.
XII. Corona heating problem
Above the visible surface of the Sun ( photosphere), having a temperature of about 6000 K, there is a solar corona with a temperature of more than 1,000,000 K. It can be shown that the direct flow of heat from the photosphere is not enough to lead to such a high temperature of the corona.
It is assumed that the energy for heating the corona is supplied by turbulent movements of the subphotospheric convective zone. In this case, two mechanisms have been proposed for energy transfer to the corona. Firstly, this is wave heating - sound and magnetohydrodynamic waves generated in the turbulent convective zone propagate into the corona and are dissipated there, while their energy is converted into the thermal energy of the coronal plasma. An alternative mechanism is magnetic heating, in which magnetic energy continuously generated by photospheric motions is released by magnetic field reconnection in the form of large solar flares or a large number of small flares.
It is currently unclear what type of waves provides an effective mechanism for heating the corona. It can be shown that all waves, except magnetohydrodynamic Alfvén waves, are scattered or reflected before reaching the corona, while the dissipation of Alfvén waves in the corona is difficult. Therefore, modern researchers have focused their attention on the heating mechanism through solar flares.
One of the possible candidates for the sources of heating of the corona is continuously occurring small-scale flares, although final clarity on this issue has not yet been achieved.
XIII. Observations of the Sun and danger to vision
To effectively observe the Sun, there are special, so-called solar telescopes, which are installed in many observatories around the world. Observations of the Sun have the peculiarity that the brightness of the Sun is high, and therefore, the aperture ratio of solar telescopes can be small. It is much more important to obtain the largest possible image scale, and to achieve this goal, solar telescopes have very long focal lengths (meters and tens of meters). It is not easy to rotate such a structure, but this is not required. The position of the Sun in the sky is limited by a relatively narrow belt, its maximum width is 46 degrees. Therefore, sunlight is directed using mirrors into a permanently installed telescope, and then projected onto a screen or viewed using dark filters.
The Sun is far from the most powerful star in existence, but it is relatively close to Earth and therefore shines very brightly - 400,000 times brighter than the full Moon. Therefore, looking at the Sun during the day with the naked eye, and even more so through binoculars or a telescope, is extremely dangerous - it causes irreversible damage to vision. Observations of the Sun with the naked eye without damage to vision are possible only at sunrise or sunset (then the Sun's brilliance weakens several thousand times), or during the day with the use of light filters. When making amateur observations through binoculars or a telescope, you should also use a darkening filter placed in front of the lens. However, it is better to use another method - projecting a solar image through a telescope onto a white screen. Even with a small amateur telescope, you can study sunspots in this way, and in good weather you can see granulations and faculae on the surface of the Sun.
XIV. Sun and Earth
For people, animals and plants, sunlight is very important. For a significant proportion of them, light causes a change in the circadian rhythm. Thus, according to some studies, a person is influenced by light with an intensity of more than 1000 lux, and its color matters.
Areas of the Earth that receive little sunlight on average each year, such as the tundra, experience low temperatures (down to −35°C in winter), a short growing season, little biodiversity, and stunted vegetation.
Green plant leaves contain the green pigment chlorophyll. This pigment plays an important role as a recipient of light energy in the process of photosynthesis. With the help of chlorophyll, the reaction of carbon dioxide and water occurs - photosynthesis, and one of the products of this reaction is the element oxygen. The reaction of water and carbon dioxide occurs with the absorption of energy, so in the dark the first phase of photosynthesis does not occur. Photosynthesis, converting solar energy and producing oxygen, gave rise to all life on Earth. This reaction produces glucose, which is the most important raw material for the synthesis of cellulose, which all plants are made of. By eating plants, in which energy has been accumulated due to the Sun, animals also exist.
The earth's surface and lower layers of air - the troposphere, where clouds form and other meteorological phenomena occur, directly receive energy from the Sun. The main influx of energy into the atmosphere-Earth system is provided by solar radiation in the spectral range from 0.1 to 4 microns. Moreover, in the range of 0.3 microns to 1.5-2 microns, the Earth’s atmosphere is almost completely transparent to solar radiation. In the ultraviolet region of the spectrum (for waves shorter than 0.3 microns), radiation is absorbed mainly by the ozone layer located at altitudes of 20-60 km. X-ray and gamma radiation practically do not reach the Earth's surface. The energy flux density from the Sun at a distance of 1 astronomical unit is about 1367 W/m² (solar constant). According to data for 2000-2004, averaged over time and over the Earth's surface, this flux is 341 W/m² or 1.74 10 17 W calculated on the total surface of the Earth (the total radiation of the Sun is approximately 2.21 10 9 times more).
In addition, a stream of ionized particles (mainly helium-hydrogen plasma) penetrates into the Earth’s atmosphere, flowing from the solar corona at a speed of 300-1200 km/s into the surrounding outer space (solar wind), visible in many areas near the poles of the planet, like “ northern lights" (polar lights). Also, many other natural phenomena are associated with the solar wind, in particular magnetic storms. Magnetic storms, in turn, can affect terrestrial organisms. The branch of biophysics that studies such influences is called heliobiology.
Also important is solar radiation in the ultraviolet range. Thus, under the influence of ultraviolet radiation, vital vitamin D is formed. With its deficiency, a serious disease occurs - rickets. Due to the lack of ultraviolet rays, the normal supply of calcium may be disrupted, as a result of which the fragility of small blood vessels increases and tissue permeability increases. However, prolonged exposure to ultraviolet radiation promotes the development of melanoma, various types of skin cancer, and accelerates aging and the appearance of wrinkles. The Earth is protected from excess radiation by the ozone layer, without which it is believed that life would not be able to escape from the oceans at all.
XV. The sun in world religion
Like many other natural phenomena, throughout the history of human civilization, the Sun has been an object of worship in many cultures. The cult of the Sun existed in Ancient Egypt, where Ra was the solar deity. The Greek god of the Sun was Helios, who, according to legend, rode across the sky every day in his chariot. In the ancient Russian pagan pantheon there were two solar deities - Khors (the actual personified sun) and Dazhdbog. In addition, the annual festive and ritual cycle of the Slavs, like other peoples, was closely connected with the annual solar cycle, and its key moments (solstices) were personified by such characters as Kolyada (Ovsen) and Kupala.
For most peoples, the solar deity was male (for example, in English, in relation to the Sun, the personal pronoun “he” - “he”) is used, but in Scandinavian mythology, the Sun (Sul) is a female deity.
In East Asia, particularly Vietnam, the Sun is represented by the symbol 日 (Chinese pinyin rì), although there is also another symbol, 太阳 (tai yang). In these indigenous Vietnamese words, the words nhật and thái dương indicate that in East Asia, the Moon and the Sun were considered two opposites - yin and yang. Both the Vietnamese and the Chinese in ancient times considered them to be the two primary forces of nature, with the Moon being considered associated with yin and the Sun with yang.
XVI. The sun in the languages of the world
In many Indo-European languages, the Sun is denoted by a word with the root sol. Yes, word sol means "Sun" in Latin and in modern Portuguese, Spanish, Icelandic, Danish, Norwegian, Swedish, Catalan and Galician. In English the word Sol also sometimes (mainly in scientific contexts) used to refer to the Sun, but the main meaning of this word is the name of a Roman god. In Persian sol means "solar year".
From the same root the Old Russian word sun, modern Russian Sun, as well as corresponding words in many other Slavic languages.
The currency of the state of Peru (new sol), formerly called inti(this was the name of the sun god of the Incas, who occupied a key place in their astronomy and mythology), which translated from the Quechua language means Sun.
XVII.Conclusion
The Sun is the only star in the Solar System. It is a huge ball of hot gas, consisting mainly of hydrogen and helium. The source of energy in the Sun is the thermonuclear reaction of converting hydrogen into helium, which occurs in the core of the star.
For people, animals and plants, the Sun is the main source of life, light and heat. And I am very glad that in our Cosmic Galaxy there is such a star named the Sun.
XIX.Bibliography
http://science.grimuar.info
http://ru.wikipedia.org
http://space.rin.ru
http://www.walkinspace.ru
Research project: “A star called the Sun. What will happen if the Sun goes out? Author of the project: 2nd grade student Author of the project: 2nd grade student of MBOU Efremovskaya secondary school MBOU Efremovskaya secondary school Dobrovolsky Alexander Dobrovolsky Alexander Project leader: Project leader: primary school teacher Gorelik Nadezhda Nikolaevna s.Efremovka 2014 s.Efremovka 2014
INTRODUCTION One day, looking through a telescope with my dad at the starry sky, I realized that this was very interesting to me. One day, looking through a telescope with my dad at the starry sky, I realized that this was very interesting to me. But the daylight attracts me no less. The brightest star - the source of light and heat - is a mystery to me.
Without the sun, life on Earth is impossible. The sun plays a big role in our lives: we are happy when the weather is clear outside - warm, light, and not in a bad mood. We see this in the example of spring and summer, when nature “comes to life”, birds fly in, insects and animals wake up.
Abstract We do not study the subject “Astronomy” at school yet. But since I am interested in the mysteries of the Universe, I decided to study it on my own with my mother. I’ll say right away that this is not only very interesting, but also educational. The solar system “swallowed” me entirely. I have been interested for a very long time: How old is the Sun, how long will it illuminate our planet, how did the Sun appear, etc. I assume that the Sun is the most ancient, burning star, without which not a single living creature on Earth can live. I shared my knowledge with my peers and friends. At school, for class time, I prepared a report on the topic: “Mysteries of the Universe.” I told my grandparents about my work.
Research objectives 1. Get acquainted with the term “Sun”. 2. Study the structure of the Sun, research scientific material about the significance of the Sun for people, animals, plants (on cacti) and the entire surrounding world. 3. Conduct a test survey about the Sun and its influence, check and compare the answers, draw a conclusion. 4. Conduct an experiment with cacti.
Conducting research The Sun is a giant flaming ball of gas with a radius of about km. Nine planets revolve around the sun, including the Earth, which together with our star make up the solar system. The distance from the Sun to the Earth is about 150 million km.
Test survey Below is a test survey: 1. Will the Sun always shine? a) yes there were 5 answers a) yes there were 5 answers b) no - 9 answers b) no - 9 answers c) probably - 8 answers c) probably - 8 answers 2. What will happen if the Sun goes out? a) everything will die - 22 answers a) everything will die - 22 answers b) animals will die -0 answers b) animals will die -0 answers c) plants will die - 0 c) plants will die - 0 d) people will die - 0 d) people will die – 0 3. For whom is the Sun more important? a) for people - 0 answer a) for people - 0 answer b) for animals - 0 b) for animals - 0 c) for plants - 1 c) for plants - 1 d) for everyone - 21 answers d) for everyone - 21 answers 4. What is more important: the Sun or the Earth? a) Sun - 1 answer a) Sun - 1 answer b) Earth - 1 answer b) Earth - 1 answer c) all - 20 c) all Can the Sun explode? a) yes - 3 people answered a) yes - 3 people answered b) no - 2 answers b) no - 2 answers c) possible - 17 answers c) possible - 17 answers The purpose of the survey was to identify the meaning of the Sun in life for each of them participating. in life for everyone involved. A total of 22 people took part in the survey.
Test survey The purpose of the survey was to identify the meaning of the Sun in life for each participant. CONCLUSION: children from a young age understand that the Sun is important for everyone. The Earth and the Sun are necessary for man. It is impossible to imagine life without the Sun. Perhaps our Sun was born from interstellar matter that remained from a supernova explosion in the distant past.
Conclusion Astronomer is not a profession, but a vocation. Studying space, the structure of planets, stars is a very interesting and necessary thing. I know when I have my own telescope, I will make my first discovery. I will find the constellation Taurus in the sky, open it and give the star to my sister.
Bright sunlight is a source of excellent mood and vigor. In cloudy weather, many people feel depressed and succumb to depression. Despite this, everyone knows that the bad weather will soon end and the sun will appear in the sky. It has been familiar to people since childhood, and few people think about what this luminary represents. The most known information about the Sun is that it is a star. However, there are still many interesting facts that may be of interest to both children and adults.
What is the Sun?
Now everyone knows that the Sun is a star, and not a huge one resembling a planet. It is a cloud of gases with a core inside. The main component of this star is hydrogen, which occupies about 92% of its total volume. About 7% is helium, and the remaining percentage is divided among other elements. These include iron, oxygen, nickel, silicon, sulfur and others.
Most of the star's energy is generated by thermonuclear fusion of helium from hydrogen. Information about the Sun collected by scientists allows us to classify it as type G2V according to spectral classification. This type is called a "yellow dwarf". At the same time, the sun, contrary to popular belief, shines with white light. The yellow glow appears as a result of the scattering and absorption of the short-wave part of the spectrum of its rays by the atmosphere of our planet. Our luminary - the Sun - is an integral part of the galaxy. From its center, the star is located at a distance of 26,000 light years, and one revolution around it takes 225-250 million years.
Solar radiation
The Sun and Earth are separated by a distance of 149,600 thousand km. Despite this, solar radiation is the main source of energy on the planet. Not all of its volume passes through the Earth's atmosphere. The energy of the sun is used by plants in the processes of photosynthesis. In this way, various organic compounds are formed and oxygen is released. Solar radiation is also used to generate electricity. Even the energy of peat reserves and other minerals appeared in ancient times under the influence of the rays of this bright star. Ultraviolet radiation from the sun deserves special attention. It has antiseptic properties and can be used to disinfect water. Ultraviolet radiation also affects biological processes in the human body, causing tanning on the skin, as well as the production of vitamin D.
Life cycle of the Sun
Our luminary, the Sun, is a young star belonging to the third generation. It contains a large amount of metals, which indicates that it was formed from other stars of previous generations. According to scientists, the Sun is about 4.57 billion years old. Considering that is 10 billion years, she is now in the middle of it. At this stage, thermonuclear fusion of helium from hydrogen occurs in the solar core. Gradually, the amount of hydrogen will decrease, the star will become hotter, and its luminosity will be higher. Then the hydrogen reserves in the core will run out completely, part of it will go into the outer shell of the Sun, and helium will begin to become denser. The processes of star extinction will continue for billions of years, but will still lead to its transformation first into a red giant, then into a white dwarf.
Sun and Earth
Life on our planet will depend on the degree of solar radiation. In about 1 billion years, it will be so strong that the surface of the Earth will heat up significantly and become uninhabitable for most forms of life, they will be able to remain only in the depths of the oceans and in the polar latitudes. By the age of the Sun, at about 8 billion years, conditions on the planet will be close to those that currently exist on Venus. There will be no water left at all; it will all evaporate into space. This will lead to the complete disappearance of various forms of life. As the Sun's core contracts and its outer shell expands, the likelihood of our planet being absorbed by the outer layers of the star's plasma will increase. This will not happen only if the Earth revolves around the Sun at a greater distance as a result of a transition to another orbit.
A magnetic field
Information about the Sun collected by researchers indicates that it is a magnetically active star. what he creates changes its direction every 11 years. Its intensity also varies over time. All these transformations are called solar activity, which is characterized by special phenomena, such as wind and flares. They are the cause and negatively affect the operation of some devices on Earth and the well-being of people.
Solar eclipses
Information about the Sun, collected by our ancestors and surviving to this day, contains references to its eclipses since antiquity. A large number of them were also described during the Middle Ages. A solar eclipse is the result of a star being obscured by the Moon from an observer on Earth. It can be complete when the solar disk is completely hidden from at least one point on our planet, or partial. There are usually between two and five eclipses in a year. At a certain point on the Earth they arise with a time difference of 200-300 years. Those who like to look at the sky and the Sun can also see an annular eclipse. The moon covers the disk of the star, but due to its smaller diameter it cannot completely eclipse it. As a result, the “ring of fire” remains visible.
It is worth remembering that observing the Sun with the naked eye, especially through binoculars or a telescope, is very dangerous. This can lead to permanent visual impairment. The sun is relatively close to the surface of our planet and shines very brightly. Without endangering your eye health, you can only look at it during sunrises and sunsets. The rest of the time you need to use special darkening filters or project an image obtained using a telescope onto a white screen. This method is the most acceptable.
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Research project: A star named the Sun Project author: 1st grade student of the Municipal Educational Institution "Tyunevskaya Secondary School" Khnychev Denis Project leader: teacher of the highest category Plastinina O. A. Tyunevo - 2009Slide 2
INTRODUCTION One day, looking through a telescope with my dad at the starry sky, I realized that this was very interesting to me. But the daylight attracts me no less. The brightest star - the source of light and heat - is a mystery to me.Slide 3
Abstract We do not study the subject “Astronomy” at school yet. But since I am interested in the mysteries of the Universe, I decided to study it on my own with my mother. I’ll say right away that this is not only very interesting, but also educational. The solar system “swallowed” me entirely. I have been interested for a very long time: How old is the Sun, how long will it illuminate our planet, how did the Sun appear, etc. I assume that the Sun is the most ancient, burning star, without which not a single living creature on Earth can live. I shared my knowledge with my peers and friends. During class time at school I prepared a report on the topic: “Mysteries of the Universe.” I told my grandparents about my work.Slide 4
Contents Introduction. Annotation. Purpose of the study. Research objectives. My suggestion. Research methods. Conducting research.Slide 5
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Research objectives: Study the literature on this topic. Get acquainted with the structure of the solar system. Find out what the Sun and the Solar Galaxy are. Provide information about the effect of sunlight on all living things.Slide 7
My assumption I assume that the sun is not only the largest and brightest star - it is the source for all life on our planet. Research work will help me figure this out.Slide 8
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Conducting research I once wondered why the Sun is not visible at night? When I was very little, my mother told me that at night the Sun sleeps with us, that’s why he is invisible. But one day we read the book “In the World of Interesting” by K.I. Mukhin, and then my mother introduced me to the encyclopedia on astronomy and then I understood everything... It turns out that our Sun is an asterisk, and quite ordinary and of the most average size. Like all stars, the Sun is a ball of luminous gas that emits light and heat.Slide 10
But if this is a star, then why don’t the other stars shine so brightly? We also found the answer to this question. The Sun and the planets in its orbit form the Solar System, which includes the rest of the stars. But they seem tiny to us, and this is because they are very far from us. In fact, some of them are many times the size of the Sun in diameter. While studying our Galaxy, which is called the Milky Way, I noticed that everything is interconnected. All planets are strictly in their own orbit, each planet has its own satellites. So our planet Earth has one satellite - the Moon. Sunlight reaches our planet in 8 minutes and 20 seconds. The surface temperature of the Sun is approximately 6000 degrees Celsius.Slide 11
The Sun is almost 5 thousand million years old, and, according to astronomers, it will exist for the same amount of time, and then it will begin to slowly die. When I read about this, I was happy at first. And I was glad that it would not go out while I lived. But then I got scared, because other people will live after me and they cannot do without sunlight, just as they cannot do without water and oxygen. The sun is a single star, but many others are binary, that is, they consist of 2 stars revolving around each other. As an example, I will say that one of the largest stars is the star Antares; its diameter is 350 times the diameter of the Sun. Our Galaxy consists of approximately 100,000 million stars, and its width is about 100,000 light years.Slide 12
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