What is the sun? brief description. Description, composition and internal structure of the sun. Information about the sun as one of these stars
Sooner or later, every earthling asks this question, because the existence of our planet depends on the Sun, and it is its influence that determines all the most important processes on Earth. The sun is a star.
There are a number of criteria according to which a celestial body can be classified as a planet or star, and the Sun meets exactly those characteristics that are inherent in stars.
Main characteristics of stars
First of all, a star differs from a planet in its ability to emit heat and light. Planets only reflect light and are essentially dark celestial bodies. The surface temperature of any star is much higher than the surface temperature.
The average surface temperature of stars can range from 2 thousand to 40 thousand degrees, and the closer to the core of the star, the higher this temperature. Near the center of the star it can reach millions of degrees. The temperature on the surface of the Sun is 5.5 thousand degrees Celsius, and inside the core it reaches 15 million degrees.
Stars, unlike planets, do not have orbits, while any planet moves in its orbit relative to the star that forms the system. In the Solar System, all the planets, their satellites, meteorites, comets, asteroids and cosmic dust move around the Sun. The Sun is the only star in the Solar System. 
Any star with its mass exceeds even the most large planet. The Sun accounts for almost the entire mass of the entire solar system– the mass of the star is 99.86% of the total volume.
The diameter of the Sun at the equator is 1 million 392 thousand kilometers, which is 109 times greater than the equatorial diameter of the Earth. And the mass of the sun is approximately 332,950 times greater than the mass of our planet - it is 2x10 to the 27th power of tons.
Stars are made mostly of light elements, unlike planets, which are made of solid and light particles. The sun is 73% by mass and 92% by volume hydrogen, 25% by mass and 7% by volume - helium. A very small share (about 1%) is made up of an insignificant amount of other elements - nickel, iron, oxygen, nitrogen, sulfur, silicon, magnesium, calcium, carbon and chromium.
Another distinctive feature of a star is the nuclear or thermal energy occurring on its surface. nuclear reactions. These are the reactions that occur on the surface of the Sun: some substances are rapidly transformed into others, releasing large amounts of heat and light.
It is the products of thermonuclear reactions occurring in the Sun that provide the Earth with the necessary energy. But on the surface of planets such reactions are not observed.
Planets often have satellites, some celestial bodies even have several. A star cannot have satellites. Although there are also planets without satellites, therefore this sign can be considered indirect: the absence of a satellite is not yet an indicator that the celestial body is a star. To do this, the other listed signs must also be present.
The sun is a typical star
So, the center of our solar system - the Sun - is a classical star: it is much larger and heavier than even the most major planets, consists of 99% light elements, emits heat and light during thermonuclear reactions occurring on its surface. The sun has no orbit and no satellites, but eight planets and other celestial bodies that are part of the solar system revolve around it.
The Sun for a person observing it from Earth is not a small point, like other stars. We see the Sun as a large bright disk because it is located quite close to the Earth.
If the Sun, like other stars visible in the night sky, moved trillions of kilometers away from our planet, we would see it as the same tiny star as we see other stars now. On a cosmic scale, the distance between the Earth and the Sun - 149 million kilometers - is not considered large.
According to scientific classification, the Sun belongs to the category of yellow dwarfs. Its age is about five billion years, and it shines with a bright and even yellow light. Why the light of the Sun? This is due to its temperature. To understand how the color of stars is formed, we can recall the example of hot iron: first it turns red, then acquires an orange tone, then yellow. 
If iron could be heated further, it would turn white and then blue. Blue stars are the hottest: the temperature on their surface is more than 33 thousand degrees.
The Sun belongs to the category of yellow stars. Interestingly, within seventeen light years, where there are approximately fifty star systems, the Sun is the fourth brightest star.
Since ancient times, the Sun has delighted people all over the world. It is no coincidence that in various parts of our planet solar myths and cults existed, and in some places still exist, which to one degree or another are characterized by the veneration of the Sun. They played important role in the religions of the Egyptians, Indians, Indians, and also, according to some scientists, in the Slavic religions. Not yet having the equipment that modern scientists have, and not knowing what it’s like internal structure The sun, our ancestors understood that it is the source of life on Earth.
The Sun is one of the stars of the Milky Way, the only star in the Solar System. According to the spectral classification, it belongs to the class of yellow dwarfs. The Sun is not a very hot and relatively small star, but relative to the Earth its size is enormous. At all points of the Sun, a balance of gravity and gas pressure is always maintained. These forces act in opposite directions to each other. Thus, thanks to their optimal ratio, the Sun remains a fairly stable astronomical body. Composition and internal structure of the Sun in this moment quite well studied.
Composition of the Sun
The Sun contains approximately 75% hydrogen and 25% helium by mass (92.1% hydrogen and 7.8% helium by number of atoms). Other elements (silicon, oxygen, nitrogen, sulfur, magnesium, calcium, chromium, iron, nickel, carbon and neon) make up only 0.1% of total mass.
Scientists have long tried to get an idea of the composition and internal structure of the Sun, using astronomy methods such as observation, spectroscopy, theoretical analysis, etc. As a result, they came to the conclusion that thanks to the explosion, a star was born, consisting mainly of helium and hydrogen. Their ratio varies because deep in the Sun, hydrogen is converted into helium due to the constant process of nuclear fusion. Starting this process is impossible without extremely high temperature and large mass celestial body.
Internal structure of the Sun
The sun is a spherical body in equilibrium. At equal distances from the center, the physical indicators are the same everywhere, but they change steadily as you move from the center to the conditional surface. The sun has several layers, and their temperature is higher the closer they are to the middle. It should be mentioned that helium and hydrogen in different layers have different characteristics.
solar core
The core is the central part of the Sun. It has been established experimentally that the size of the solar core is approximately 25% of the entire radius of the Sun and consists of highly compressed matter. The mass of the core is almost half of the total mass of the Sun. Conditions at the core of our star are extreme. Temperature and pressure reach their maximum there: the temperature of the core is approximately 14 million K, and the pressure in it reaches 250 billion atm. The gas in the solar core is more than 150 times denser than water. This is exactly the place where the thermonuclear reaction occurs, accompanied by the release of energy. Hydrogen turns into helium, and with it light and heat appear, which then reach our planet and give it life.
At a distance from the core of more than 30% of the radius, the temperature becomes less than 5 million degrees, so nuclear reactions almost no longer occur there.
Radiative transfer zone
The radiative transfer zone is located at the core boundary. Presumably, it occupies about 70% of the entire radius of the star and consists of hot matter through which thermal energy is transferred from the core to the outer layer.
As a result of the thermonuclear reaction occurring in the solar core, various radiation photons are produced. Having passed through the radiative transfer zone and all subsequent layers, they are thrown into space and wander around there along with the solar wind, which reaches the Earth from the Sun in just 8 minutes. Scientists have been able to establish that it takes photons approximately 200,000 years to overcome this zone.
Not only the Sun, but also other stars have a radiative transfer zone. Its magnitude and strength depend on the size of the star.
Convective zone
The convection zone is the last in the internal structure of the Sun and other stars similar to it. It is located outside the radiative transfer zone and occupies the last 20% of the Sun's radius (about a third of the star's volume). The energy in it is transferred by convection. Convection is the transfer of heat in jets and currents through active mixing. This process is similar to boiling water. Streams of hot gas move to the surface and give off heat outside, and the cooled gas rushes back into the depths of the Sun, due to which the nuclear fusion reaction continues. As it approaches the surface, the temperature of the material in the convective zone drops to 5800 K. Almost all stars have a convective zone, like a radiative transfer zone.
All of the above layers of the Sun are not observable.
Atmosphere of the Sun
Above the convective zone there are several observable layers of the Sun - the atmosphere. Her chemical composition determined by the method spectral analysis. The internal structure of the Sun's atmosphere includes three layers: the photosphere (translated from Greek as “sphere of light”), the chromosphere (“colored sphere”) and the corona. It is in the last two layers that magnetic flares occur.
Photosphere
The photosphere is the only layer of the Sun visible from our planet. The temperature of the photosphere is 6000 K. It glows with white-yellow light. It is the middle of this layer that is considered the conventional surface of the Sun and is used to calculate distances, that is, to measure height and depth.
The thickness of the photosphere is about 700 km, it consists of gas and emits solar radiation reaching the Earth. The upper layers of the photosphere are colder and more rarefied than the lower ones. Waves arising in the convective zone and photosphere transfer mechanical energy to the overlying regions and heat them. As a result, the upper part of the photosphere is the coldest - about 4500 K. On both sides of them the temperature rises rapidly.
Chromosphere
Chromosphere - next to the photosphere, very rarefied air envelope The sun, consisting primarily of hydrogen. Due to its extraordinary brightness, it can only be seen during a total solar eclipse. The word "chromosphere" is translated from Greek as "colored sphere". When the Moon obscures the Sun, the chromosphere becomes pinkish due to the presence of hydrogen. This layer is cooler than the previous one because its density is lower. The temperature of gases in the upper layers of the chromosphere is 50,000 K.
At an altitude of 12,000 km above the photosphere, the hydrogen spectrum line becomes indistinguishable. Traces of calcium were recorded slightly higher. Its spectrum line ends after another 2,000 km. The farther from the surface of the Sun, the hotter and more rarefied the gas is.
Crown
At an altitude of 14,000 km above the photosphere, the corona begins - the third outer shell of the Sun. The corona consists of energetic eruptions and prominences - special plasma formations. Its temperature varies from 1 to 20 million K, there are also coronal holes with a temperature of 600 thousand K, where the solar wind comes from. Starting from the bottom, the temperature increases, and at an altitude of 70,000 km from the surface of the Sun it begins to decrease.
The upper limit of the corona has not yet been determined, nor has the exact cause of the unusually high temperature. Like the chromosphere, the solar corona is also visible only during eclipses or when using special equipment. Solar corona is a powerful source of constant X-ray and ultraviolet radiation.
Today, humanity knows quite a lot about the internal structure of the Sun and the processes occurring in it. Technological progress has greatly contributed to the clarification of their nature. By gaining knowledge about the Sun, you can get an idea about other stars. But since the Sun can only be observed from afar, it still has many unsolved mysteries.
– the only star in the solar system: description and characteristics with photos, Interesting Facts, composition and structure, location in the galaxy, development.
The sun is the center and source of life for our solar system. The star belongs to the class of yellow dwarfs and occupies 99.86% of the total mass of our system, and its gravity prevails over all celestial bodies. In ancient times, people immediately understood the importance of the Sun for earthly life, which is why mention of a bright star is found in the very first texts and rock paintings. It was the central deity ruling over all.
Let's study the most interesting facts about the Sun - the only star in the solar system.
A million Earths can fit inside
- If we fill our star, the Sun, 960,000 Earths will fit inside. But if they are compressed and deprived of free space, the number will increase to 1,300,000. The surface area of the Sun is 11,990 times larger than that of the Earth.
Holds 99.86% of system weight
- Its mass is 330,000 times greater than that of Earth. Approximately ¾ is allocated to hydrogen, and the rest to helium.
Almost perfect sphere
- The difference between the equatorial and polar diameters of the Sun is only 10 km. This means that we have before us one of the celestial bodies closest to the sphere.
Temperatures in the center rise to 15 million °C
- In the core, heat is created due to the fusion process where hydrogen is transformed into helium. Hot objects usually expand, so our star might explode but is held together by powerful gravity. The surface temperature rises to 5600 °C.
One day the sun will engulf the earth
- When the Sun uses up its entire hydrogen supply (130 million years), it will switch to helium. This will cause it to increase in size and absorb the first three planets. This is the red giant stage.
One day it will reach earth size
- After the red giant, it will collapse and leave a compressed mass in an Earth-sized ball. This is the white dwarf stage.
A ray of sunshine reaches us in 8 minutes
- The Earth is 150 million km away from the Sun. The speed of light is 300,000 km/s, so the beam takes 8 minutes and 20 seconds to travel to us. But it is also important to understand that it took millions of years for the energy to move from the solar core to the surface.
The speed of the Sun is 220 km/s
- The Sun is 24,000-26,000 light years away from the galactic center. Therefore, it spends 225-250 million years on its orbital path.
The Earth-Sun distance changes throughout the year
- The Earth moves along an elliptical orbital path, so the distance is 147-152 million km (astronomical unit).
This is a middle aged star
- The Sun is 4.5 billion years old, which means it has already burned through about half of its hydrogen reserves. But the process will continue for another 5 billion years.
A powerful magnetic field is observed
- Solar flares occur during magnetic storms. We see this as the formation of sunspots, where magnetic lines twist and spin like terrestrial tornadoes.
The star generates the solar wind
- The solar wind is a stream of charged particles passing through the entire solar system at an acceleration of 450 km/s. Wind appears where the Sun's magnetic field extends.
Name of the Sun
- The word itself comes from Old English, meaning “south.” There are also Gothic and Germanic roots. Before 700 AD Sunday was called "sunny day". Translation also played a role. The original Greek heméra helíou became the Latin dies solis.
Characteristics of the Sun
The Sun is a G-type main sequence star with an absolute magnitude of 4.83, which is brighter than about 85% of the other stars in the galaxy, many of which are red dwarfs. With a diameter of 696342 km and a mass of 1.988 x 10 30 kg, the Sun is 109 times larger than Earth and 333,000 times more massive.
It's a star, so the density varies depending on the layer. Average reaches 1.408 g/cm3. But closer to the core it increases to 162.2 g/cm 3, which is 12.4 times higher than on Earth.
It appears yellow in the sky, but the true color is white. Visibility is created by the atmosphere. The temperature increases with proximity to the center. The core is heated to 15.7 million K, the corona - 5 million K, and the visible surface - 5778 K.
| Average diameter | 1.392 10 9 m |
|---|---|
| Equatorial | 6.9551 10 8 m |
| Equator circumference | 4.370 10 9 m |
| Polar compression | 9 10 −6 |
| Surface area | 6.078 10 18 m² |
| Volume | 1.41 10 27 m³ |
| Weight | 1.99 10 30 kg |
| Average density | 1409 kg/m³ |
| Acceleration free falls at the equator |
274.0 m/s² |
| Second escape velocity (for surface) |
617.7 km/s |
| Effective temperature surfaces |
5778 K |
| Temperature crowns |
~1,500,000 K |
| Temperature kernels |
~13,500,000 K |
| Luminosity | 3.85 10 26 W (~3.75·10 28 Lm) |
| Brightness | 2.01 10 7 W/m²/sr |
The sun is made of plasma, therefore it is endowed with high magnetism. There is a north and a south magnetic poles, and the lines form the activity observed on surface layer. Dark spots mark cool spots and lend themselves to cyclicity.
Coronal mass ejections and flares occur when lines magnetic field are being reconfigured. The cycle takes 11 years, during which activity waxes and wanes. The greatest number of sunspots occurs at maximum activity.
The apparent magnitude reaches -26.74, which is 13 billion times brighter than Sirius (-1.46). The Earth is 150 million km away from the Sun = 1 AU. It takes 8 minutes and 19 seconds for a light beam to cover this distance.
Composition and structure of the Sun
The star is filled with hydrogen (74.9%) and helium (23.8%). Among more heavy elements oxygen (1%), carbon (0.3%), neon (0.2%) and iron (0.2%) are present. The inner part is divided into layers: core, radiation and convective zones, photosphere and atmosphere. The core has the highest density (150 g/cm 3) and occupies 20-25% of the total volume.
The star spends a month turning its axis, but this is an approximate estimate, because this is a plasma ball. Analysis shows that the core rotates faster than the outer layers. While the equatorial line spends 25.4 days per revolution, the poles take 36 days.
In the core of a celestial body, solar energy is formed due to nuclear fusion, transforming hydrogen into helium. Almost 99% of thermal energy is created in it.
Between the radiation and convective zones there is a transition layer - tacholine. There is a noticeable sharp change in the uniform rotation of the radiation zone and the differential rotation of the convection zone, which causes a serious shift. The convective zone is located 200,000 km below the surface, where the temperature and density are also lower.
The visible surface is called the photosphere. Above this ball, light can spread freely into space, releasing solar energy. The thickness covers hundreds of kilometers.
The upper part of the photosphere is inferior in heating to the lower part. The temperature rises to 5700 K, and the density is 0.2 g/cm3.
The atmosphere of the Sun is represented by three layers: the chromosphere, the transition part and the corona. The first extends over 2000 km. The transitional layer occupies 200 km and warms up to 20,000-100,000 K. The layer has no clear boundaries, but a halo with constant chaotic movement is noticeable. The corona warms up to 8-20 million K, which is influenced by the solar magnetic field.
The heliosphere is a magnetic sphere extending beyond the heliopause (50 AU from the star). It is also called the solar wind.
Evolution and future of the Sun
Scientists are convinced that the Sun appeared 4.57 billion years ago due to the collapse of part of a molecular cloud represented by hydrogen and helium. At the same time, it started rotation (due to angular momentum) and began to heat up with increasing pressure.
Most of the mass was concentrated in the center, and the rest turned into a disk that would later form the planets we know. Gravity and pressure led to increased heat and nuclear fusion. There was an explosion and the Sun appeared. In the figure you can trace the stages of evolution of stars.
The star is currently in the main sequence phase. Inside the core, more than 4 million tons of matter are transformed into energy. The temperature is constantly rising. Analysis shows that over the past 4.5 billion years, the Sun has become brighter by 30%, with an increase of 1% for every 100 million years.
It is believed that it will eventually begin to expand and become a red giant. Due to the increase in size, Mercury, Venus and possibly the Earth will die. It will remain in the giant phase for approximately 120 million years.
Then the process of decreasing size and temperature will begin. It will continue to burn the remaining helium in the core until the supply runs out. In 20 million years it will lose stability. The earth will be destroyed or heat up. After 500,000 years, only half the solar mass will remain, and the outer shell will create a nebula. As a result, we will get a white dwarf that will live for trillions of years and only then turn black.
Location of the Sun in the galaxy
The Sun is closer to the inner edge of the Orion Arm of the Milky Way. The distance from the galactic center is 7.5-8.5 thousand parsecs. Located inside the local bubble - a cavity in interstellar medium with hot gas.
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.
People understood long ago that without the Sun life on Earth would not exist, because he was exalted, he was worshiped, and when celebrating the day of the Sun, they often made human sacrifices. They watched it and, creating observatories, solved such simple at first glance questions about why the Sun shines during the day, what is the inherent nature of the luminary, when the Sun sets, where it rises, what objects are around the Sun, and planned their activities on based on the data obtained.
Scientists had no idea that on the only star in the solar system there are seasons very similar to the “rainy season” and the “dry season.” The activity of the Sun alternately increases in the northern and southern hemispheres, lasts eleven months, and decreases for the same amount of time. Along with the eleven-year cycle of its activity, the life of earthlings directly depends, since at this time powerful magnetic fields are emitted from the bowels of the star, causing solar disturbances that are dangerous for the planet.
Some may be surprised to learn that the Sun is not a planet. The sun is a huge, luminous ball of gases, inside of which thermonuclear reactions constantly occur, releasing energy that gives light and heat. It is interesting that such a star does not exist in the solar system, and therefore it attracts to itself all smaller objects that are in the zone of its gravity, as a result of which they begin to rotate around the Sun along a trajectory.
Naturally, in space the Solar System is not located on its own, but is part of milky way, galaxies, which is a huge star system. The Sun is separated from the center of the Milky Way by 26 thousand light years, so the movement of the Sun around it is one revolution every 200 million years. But the star rotates around its axis in a month - and even then, these data are approximate: it is a plasma ball, the components of which rotate at different speeds, and therefore it is difficult to say exactly how much time it takes for a full rotation. So, for example, in the equator region this happens in 25 days, at the poles - 11 days more.
Of all the stars known today, our Sun is in fourth place in terms of brightness (when a star exhibits solar activity, it shines brighter than when it subsides). By itself, this huge gaseous ball is white, but due to the fact that our atmosphere absorbs short-spectrum waves and the Sun’s ray at the Earth’s surface is scattered, the light of the Sun becomes yellowish, and the white color can only be seen on a clear, fine day against the background blue sky
Being the only star in the Solar System, the Sun is also the only source of its light (not counting very distant stars). Despite the fact that the Sun and Moon are the largest and brightest objects in the sky of our planet, the difference between them is huge. While the Sun itself emits light, the Earth's satellite, being a completely dark object, simply reflects it (we can say that we also see the Sun at night when the Moon illuminated by it is in the sky).
The Sun was shining - a young star, its age, according to scientists, is more than four and a half billion years. Therefore, it refers to a third generation star, which was formed from the remains of previously existing stars. It is rightfully considered the largest object in the solar system, since its weight is 743 times greater than the mass of all the planets revolving around the Sun (our planet is 333 thousand times lighter than the Sun and 109 times smaller than it).
Atmosphere of the Sun
Since the temperature of the upper layers of the Sun exceeds 6 thousand degrees Celsius, it solid body is not: with such high temperature any stone or metal is transformed into gas. Scientists came to such conclusions recently, since previously astronomers had suggested that the light and heat emitted by a star are the result of combustion.
The more astronomers observed the Sun, the clearer it became: its surface has been heated to the limit for several billion years, and nothing can burn for that long. According to one of the modern hypotheses, the same processes occur inside the Sun as in atomic bomb– matter is converted into energy, and as a result of thermonuclear reactions, hydrogen (its share in the composition of the star is about 73.5%) is transformed into helium (almost 25%).
Rumors that the Sun on Earth will sooner or later go out are not without foundation: the amount of hydrogen in the core is not unlimited. As it burns, the outer layer of the star will expand, while the core, on the contrary, will shrink, as a result of which the life of the Sun will end and it will transform into a nebula. This process will not begin soon. According to scientists, this will happen no earlier than in five to six billion years.
As for the internal structure, since a star is a gaseous ball, the only thing it has in common with a planet is the presence of a core.
Core
It is here that all thermonuclear reactions occur, generating heat and energy, which, bypassing all subsequent layers of the Sun, leave it in the form sunlight and kinetic energy. The solar core extends from the center of the Sun to a distance of 173,000 km (approximately 0.2 solar radii). Interestingly, in the core the star rotates around its axis much faster than in the upper layers.
Radiative transfer zone
Photons leaving the nucleus in the radiative transfer zone collide with plasma particles (ionized gas formed from neutral atoms and charged particles, ions and electrons) and exchange energy with them. There are so many collisions that it sometimes takes about a million years for a photon to pass through this layer, and this despite the fact that the plasma density and its temperature at the outer boundary decrease.
Tachocline
Between the radiative transfer zone and the convective zone there is a very thin layer where the magnetic field is formed - power lines The electromagnetic field is stretched by plasma flows, increasing its intensity. There is every reason to believe that here the plasma significantly changes its structure.
Convective zone
Near the solar surface, the temperature and density of matter becomes insufficient for the solar energy to be transferred only through re-radiation. Therefore, here the plasma begins to rotate, forming vortices, transferring energy to the surface, while the closer to the outer edge of the zone, the more it cools, and the gas density decreases. At the same time, the particles of the photosphere located above it, cooled on the surface, go into the convective zone.
Photosphere
The photosphere is the brightest part of the Sun that can be seen from Earth in the form of the solar surface (it is called so conventionally, since a body consisting of gas does not have a surface, so it is classified as part of the atmosphere).
Compared to the radius of the star (700 thousand km), the photosphere is a very thin layer with a thickness of 100 to 400 km.
It is here that, during solar activity, light, kinetic and thermal energy is released. Since the plasma temperature in the photosphere is lower than in other places, and there is a strong magnetic radiation, sunspots form in it, giving rise to the well-known phenomenon of solar flares.
Although solar flares do not last long, an extremely large amount of energy is released during this period. And it manifests itself in the form of charged particles, ultraviolet, optical, x-ray or gamma radiation, as well as plasma flows (on our planet they cause magnetic storms negatively affecting people's health).
The gas in this part of the star is relatively thin and rotates very unevenly: its rotation in the equator region is 24 days, at the poles - thirty. In the upper layers of the photosphere, minimum temperatures are recorded, due to which out of 10 thousand hydrogen atoms only one has a charged ion (despite this, even in this region the plasma is quite ionized).
Chromosphere
The chromosphere is the upper shell of the Sun, 2 thousand km thick. In this layer, the temperature rises sharply, and hydrogen and other substances begin to actively ionize. The density of this part of the Sun is usually low, and therefore is difficult to distinguish from the Earth, and it can only be seen in the event of a solar eclipse, when the Moon covers the brighter layer of the photosphere (the chromosphere glows red at this time).
Crown
The corona is the last outer, very hot shell of the Sun, which is visible from our planet during full solar eclipse: It resembles a radiant halo. At other times it is impossible to see it due to its very low density and brightness.
It consists of prominences, fountains of hot gas up to 40 thousand km high, and energetic eruptions that go into space at great speed, forming the solar wind, consisting of a stream of charged particles. It is interesting that many natural phenomena on our planet are associated with the solar wind, for example, northern lights. It should be noted that the solar wind itself is extremely dangerous, and if our planet was not protected by the atmosphere, it would destroy all living things.
Earth year
Our planet moves around the Sun at a speed of about 30 km/s and the period of its complete revolution is equal to one year (the length of the orbit is more than 930 million km). At the point where the solar disk is closest to the Earth, our planet is separated from the star by 147 million km, and at the most distant point - 152 million km.
The “movement of the Sun” visible from the Earth changes throughout the whole year, and its trajectory resembles a figure eight, stretched along the Earth’s axis from north to south with a slope of forty-seven degrees.
This happens due to the fact that the angle of deviation of the Earth’s axis from the perpendicular to the orbital plane is about 23.5 degrees, and since our planet revolves around the Sun, the Sun’s rays change their angle every day and hourly (not counting the equator, where day is equal to night). falls at the same point.
In the summer in the northern hemisphere, our planet is tilted towards the Sun, and therefore the rays of the Sun illuminate earth's surface as intensely as possible. But in winter, since the path of the solar disk across the sky is very low, the sun's ray falls on our planet at a steeper angle, and therefore the earth warms up weakly.
The average temperature is established when autumn or spring arrives and the Sun is located at the same distance in relation to the poles. At this time, nights and days are approximately the same length - and climatic conditions are created on Earth, which represent a transitional stage between winter and summer.
Such changes begin to take place in winter, after the winter solstice, when the trajectory of the Sun across the sky changes and it begins to rise.
Therefore, when spring comes, the Sun approaches the day spring equinox, the length of day and night becomes the same. In the summer, June 21, the day of the summer solstice, the solar disk reaches its highest point above the horizon.
Earth day
If you look at the sky from the point of view of an earthling in search of an answer to the question of why the Sun shines during the day and where it rises, then you can soon be convinced that the Sun rises in the east, and its setting can be seen in the west.
This happens due to the fact that our planet not only moves around the Sun, but also rotates around its axis, making a full revolution in 24 hours. If you look at the Earth from space, you can see that it, like most of the planets of the Sun, turns counterclockwise, from west to east. Standing on Earth and observing where the Sun appears in the morning, everything is seen in a mirror image, and therefore the Sun rises in the east.
At the same time, an interesting picture is observed: a person, observing where the Sun is, standing on one point, moves together with the Earth in an easterly direction. At the same time, parts of the planet that are located on the western side, one after another, gradually begin to be illuminated by the light of the Sun. So. for example, the sunrise on the east coast of the United States can be seen three hours earlier before the sun rises on the west coast.
The Sun in the Life of the Earth
The Sun and Earth are so connected with each other that the role of the largest star in the sky can hardly be overestimated. First of all, our planet formed around the Sun and life appeared. Also, the energy of the Sun warms the Earth, the Sun's ray illuminates it, forming a climate, cooling it at night, and after the Sun rises, warms it again. What can I say, even the air with its help acquired the properties necessary for life (if not a ray of the Sun, it would have been a liquid ocean of nitrogen surrounding blocks of ice and frozen land).
The Sun and Moon, being largest objects in the sky, actively interacting with each other, not only illuminate the Earth, but also directly influence the movement of our planet - a shining example This action ebbs and flows. They are influenced by the Moon, the Sun plays a secondary role in this process, but they cannot do without its influence either.
The Sun and the Moon, the Earth and the Sun, air and water flows, the biomass surrounding us are accessible, constantly renewable energy raw materials that can be easily used (it lies on the surface, it does not need to be extracted from the bowels of the planet, it does not generate radioactive and toxic waste ).
To draw public attention to the possibility of using renewable energy sources, since the mid-90s. last century, it was decided to celebrate International Sun Day. Thus, every year, on May 3, on the day of the Sun, seminars, exhibitions, and conferences are held throughout Europe aimed at showing people how to use the ray of the luminary for good, how to determine the time when sunset or dawn of the Sun occurs.
For example, on the day of the Sun you can attend special multimedia programs, see huge areas of magnetic disturbances and various manifestations of solar activity through a telescope. On the day of the Sun, you can look at various physical experiments and demonstrations that clearly demonstrate how powerful a source of energy our Sun is. Often on the Day of the Sun, visitors have the opportunity to create a sundial and test it in action.
