The structure of the sun. The sun in astronomy The sun structure and characteristics

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 temperature of the surface 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 has a mass greater than even the largest 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 thermonuclear reactions occurring on its surface. 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 classic star: it is much larger and heavier than even the largest 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.

The distance to it on an astronomical scale is tiny: it takes 8 minutes to reach light from the Sun to the Earth, and 149.6 million km or 1 AU passes. (astronomical unit).

Radius of the Sun 109 times, and the mass is 330,000 times the radius and mass of the Earth. Mass of the Sun accounts for 99.86% of the total mass of the entire Solar system. And the average density of the star is small - 1.4 times the density of water.

Sun composed of hydrogen (≈ 73% by mass and ≈ 92% by volume), helium (≈ 25% by mass and ≈ 7% by volume) and other elements with lower content: gland, nickel, oxygen, nitrogen, silicon, sulfur, magnesium, carbon, neon, calcium and chromium.

From stars located in 50 adjacent star systems within 17 light years, Sun- the fourth brightest star (its absolute magnitude is + 4.83 m). Most of the energy produced by our star is obtained as a product helium fusion from hydrogen.

First time contact Sun recorded Galileo by the movement of spots on the surface. Different parts of the Sun have different periods when rotating around axes. Thus, a point on the equator has a period of approximately 25 days; at a latitude of 40°, the period of revolution will be 27 days, and near the poles - 30 days. This demonstrates that the Sun does not rotate as solid, the speed of rotation of points on the surface of the Sun decreases from the equator to the poles.

Solar surface temperature reaches 6000K. These explain the phenomenon that the Sun shines almost white light. And yet, the direct light of the Sun at the borders of the Earth takes on a yellow tint due to stronger scattering and absorption of the short-wavelength part spectrum atmosphere of the Earth. It should be noted that it has been shining quite steadily for millions of years, this was substantiated by modern biological analysis of the remains of blue-green algae. Theoretical modeling of a situation where the surface temperature of the Sun would change by only 10% demonstrated that life on Earth would end.

The sun emits evenly energy, so indispensable for life on Earth. The entire energy emitted by it is equal to L = 3.86.1033 erg/s = 3.86.1026 W. This amounts to 6.5 kW from every square centimeter of surface!

And only one two-billionth part of this energy takes Earth. This energy can be used in a variety of natural and artificial treatments. So, plants, using it in photosynthesis, produce organic compounds with the release of oxygen. Direct solar heating or energy transformation photocells found application in the creation electricity(solar power plants) or carrying out other necessary work. During photosynthesis, millions of years ago, the energy contained in oil and many other types of fossil fuel.

The study of the Sun was carried out by many spacecraft, numbering about two hundred (194), but there were also specialized ones, these are:
The first spacecraft designed to observe the Sun were NASA-built Pioneer series satellites numbered 5-9, launched between 1960 and 1968. These satellites orbited the Sun close to Earth's orbit and made the first detailed measurements of the solar wind.
Orbital Solar Observatory("OSO") - a series of American satellites launched between 1962 and 1975 for the purpose of studying the Sun, in particular, in the ultraviolet and X-ray wavelengths.
SC "Helios-1"- West German AMS was launched on December 10, 1974, designed to study the solar wind, interplanetary magnetic field, cosmic radiation, zodiacal light, meteor particles and radio noise in near-solar space, as well as to conduct experiments to record phenomena predicted by the general theory of relativity. 01/15/1976 West German spacecraft launched into orbit Helios-2". 04/17/1976 "Helios-2" (Helios) for the first time approached the Sun at a distance of 0.29 AU (43.432 million km). In particular, magnetic shock waves in the range of 100 - 2200 Hz have been recorded, as well as the appearance of light helium nuclei during solar flares, which indicates high-energy thermonuclear processes in the solar chromosphere. Another interesting observation made by this program is that the spatial density of small meteorites near the Sun is fifteen times higher than near the Earth. Record speed achieved for the first time at 66.7 km/s, moving at 12g.
In 1973, the space solar observatory (Apollo Telescope Mount) on the space station became operational. Skylab. Using this observatory, the first observations of the solar transition region and ultraviolet radiation of the solar corona were made in a dynamic mode. It also helped discover “coronal mass eruptions” and coronal holes, which are now known to be closely related to the solar wind.
Solar Maximum Study Satellite("SMM") - American satellite ( Solar Maximum Mission- SMM), launched on February 14, 1980 to observe ultraviolet, x-ray and gamma radiation from solar flares during periods of high solar activity. However, just a few months after launch, due to an electronics malfunction, the probe went into passive mode. In 1984, space mission STS-41C on the Challenger shuttle fixed a problem with the probe and launched it back into orbit. After that, before its entry into the atmosphere in June 1989, the device took thousands of images of the solar corona. His measurements also helped to find out that the power of the total radiation of the Sun over a year and a half of observations changed only by 0.01% during the period of maximum solar activity.
Japanese spacecraft Yohkoh(Yoko, "Sunlight"), launched in 1991, made observations of solar radiation in the X-ray range. His findings helped scientists identify several different types of solar flares and showed that the corona, even far from areas of maximum activity, is much more dynamic than commonly thought. Yohkoh operated for a full solar cycle and went dormant during the 2001 solar eclipse when it lost its alignment with the Sun. In 2005, the satellite entered the atmosphere and was destroyed.
Solar probe "Ulysses" - The European automatic station was launched on October 6, 1990 to measure the parameters of the solar wind, the magnetic field outside the ecliptic plane, and study the polar regions of the heliosphere. Conducted a scan of the equatorial plane of the Sun up to the Earth's orbit. For the first time he recorded in the radio wave range the spiral shape of the solar magnetic field, diverging like a fan. He found that the strength of the Sun's magnetic field increases with time and has increased 2.3 times over the past 100 years. This is the only spacecraft moving perpendicular to the ecliptic plane in a heliocentric orbit. In mid-1995 it flew over the south pole of the Sun at its minimum activity, and on November 27, 2000 it flew for the second time, reaching a maximum latitude in the southern hemisphere of -80.1 degrees. 04/17/1998 AC " Ulysses " completed its first orbit around the Sun. February 7, 2007 The Ulysses probe "passed" an important milestone during its mission - for the third time during its flight, it passed above 80 degrees south latitude on the surface of the Sun. This trajectory passage over the polar region of our star began in November 2006 and became the third in the sixteen-year history of the probe’s operation. Once every 6.2 years it makes a revolution around our star and during each revolution it passes over the polar regions of the Sun. During the flight, scientists received a lot of new scientific information. During such flybys, the satellite first circles the south pole of the Sun, and then the north pole. Ulysses confirmed the existence of a fast solar wind from the solar poles of approximately 750 km/s, which is less than expected.
Solar Wind Study Satellite Wind" - American research vehicle, launched on November 1, 1994 into orbit with the following parameters: orbital inclination - 28.76º; T=20673.75 min.; P=187 km; A=486099 km. On August 19, 2000, he made his 32nd flyby of the Moon. Using the WIND spacecraft, researchers were able to make rare direct observations of magnetic reconnection, which allows the Sun's magnetic field, conducted by the solar wind, to couple with Earth's magnetic field, allowing plasma and energy from the Sun to flow into Earth's space, causing auroras and magnetic storms.
Solar and Heliospheric Observatory ("SOHO") - A research satellite (Solar and Heliospheric Observatory - SOHO), launched by the European Space Agency on December 2, 1995 with an expected operational life of about two years. It was launched into orbit around the Sun at one of the Lagrange points (L1), where the gravitational forces of the Earth and the Sun are balanced. Twelve instruments on board the satellite are designed to study the solar atmosphere (in particular, its heating), solar oscillations, processes of the removal of solar matter into space, the structure of the Sun, as well as processes in its interior. Conducts constant photography of the Sun. On 02/04/2000, the solar observatory "SOHO" celebrated a kind of anniversary. In one of the photographs taken by SOHO, a new comet was discovered, which became the 100th in the observatory's track record, and in June 2003 it discovered the 500th comet. On January 15, 2005, the 900th tailed wanderer was discovered. And the anniversary, 1000th, was opened on August 5, 2005. On June 25, 2008, using data obtained by the SOHO solar observatory, the “anniversary”, 1500th comet was discovered.
Ongoing observations with SOHO have shown that supergranules are moving across the solar surface faster than the Sun rotates. In January 2003, a group of scientists led by Laurent Gizon from Stanford University managed to explain this mysterious phenomenon. Supergranulation is a pattern of activity that moves in waves across the solar surface. This phenomenon can be compared to the “movement of a wave” in the stands of a stadium, when each of the fans sitting next to each other gets up from their seat for a short time and then sits down, but does not move either to the right or to the left, while creating an illusion for an observer from the side. a wave running across the stands. Similar waves are created by rising and falling supergranules. The waves propagate in all directions across the solar surface, but for some reason they are stronger (have greater amplitude) in the direction of the solar rotation. Since these waves are the most prominent, the illusion is created that they are moving faster than the speed of rotation of the Sun. It is quite difficult to make an assumption about the physical cause of this phenomenon, but probably the rotation itself is the source of supergranulation waves.
Videos made from new observations transmitted by TRACE allowed astronomers to see bright plasma streaks running up and down the coronal loops. Data obtained from SOHO confirmed that these inclusions are moving at enormous speed, and led to the conclusion that coronal loops are not static structures filled with plasma, but rather ultra-high-speed flows of plasma that are “shot” from the solar surface and “ splash" between structures in the corona.
Satellite for studying the solar corona "TRACE" (Transition Region & Coronal Explorer)" launched on April 2, 1998 into orbit with the following parameters: orbit - 97.8 degrees; T = 96.8 minutes; P = 602 km; A = 652 km.
The task is to explore the transition region between the corona and the photosphere using a 30-cm ultraviolet telescope. Study of the loops showed that they consist of a number of individual loops connected to each other. The gas loops heat up and rise along the magnetic field lines to a height of up to 480,000 km, then cool down and fall back at a speed of more than 100 km/s.
On July 31, 2001, the Russian-Ukrainian observatory was launched Coronas-F» to observe solar activity and study solar-terrestrial connections. The satellite is in low-Earth orbit with an altitude of about 500 km and an inclination of 83 degrees. Its scientific complex includes 15 instruments that observe the Sun in the entire range of the electromagnetic spectrum - from optics to gamma-ray.
During the observation period, the CORONAS-F instruments recorded the most powerful flares on the Sun and their impact on near-Earth space; a huge number of X-ray solar spectra and images of the Sun were obtained, as well as new data on the fluxes of solar cosmic rays and ultraviolet radiation from the Sun. /more news from September 17, 2004/.
Genesis satellite launched on August 8, 2001 to study the solar wind. Coming out at the L1 libration point, the American research probe began collecting solar wind on December 3, 2001. In total, Genesis collected from 10 to 20 micrograms of solar wind elements - the weight of several grains of salt - of interest to scientists. But the Genesis device landed very hard on September 08, 2004 (it crashed at a speed of 300 km/h) in the Utah desert (the parachutes did not open). However, scientists were able to extract remnants of the solar wind from the debris for study.
On September 22, 2006, the solar observatory HINODE (Solar-B, Hinode). The observatory was created at the Japanese Institute ISAS, where the Yohkoh Observatory (Solar-A) was developed, and is equipped with three instruments: SOT - solar optical telescope, XRT - X-ray telescope and EIS - ultraviolet imaging spectrometer. The main task of HINODE is to study active processes in the solar corona and establish their connection with the structure and dynamics of the solar magnetic field.
The solar observatory was launched in October 2006 STEREO. It consists of two identical spacecraft in such orbits that one of them will gradually lag behind the Earth, and the other will overtake it. This will make it possible to use them to obtain stereo images of the Sun and solar phenomena such as coronal mass eruptions.

The sun is our everything! This is light, this is warmth and much more. Without the Sun, life would not have arisen on Earth. Therefore, I really want to dedicate this material to our luminary.

The Sun is the only star located at the center of our solar system and the Earth's climate and weather conditions depend on it.

By galactic standards, our star is barely noticeable, even in the nearest space. The Sun is just one of the stars of average size and mass, among the 100 billion stars found in our Galaxy, the Milky Way alone.

Our star is composed of 70% hydrogen and 28% helium. The remaining 2% is occupied by particles emitted into space and new elements synthesized by the star itself.

The hot gases that formed the Sun—mostly hydrogen and helium—exist in an incredibly hot, electrified state called plasma.

The energy power of the Sun is about 386 billion megawatts and is produced by the process of fusion of hydrogen nuclei, which is commonly called thermonuclear fusion.

In the distant, distant past, the Sun shone weaker than it does now. Continuous observations of radiation maxima over several decades allowed scientists to conclude that the increase in the luminosity of the Sun continues in our time. Thus, in just the last few cycles, the total luminosity of the Sun has increased by approximately 0.1%. Such changes have a huge impact on our lives.

In addition to thermal energy and the light we see, the Sun emits a giant stream of charged particles into space called the solar wind. It moves through the solar system at a speed of approximately 450 kilometers per second.

Age of the Sun According to scientists' calculations, it is about 4.6 billion years. This makes it highly likely that it will continue to exist in its current form for another 5 billion years. Eventually, the Sun will engulf the Earth. When all the hydrogen burns out, the Sun will exist for about 130 million more years, burning helium. During this period it will expand to such an extent that it will engulf Mercury, Venus and Earth. At this stage, it can be called a red giant.

Sunlight takes approximately 8 minutes to reach the Earth's surface. With an average distance of 150 million kilometers to Earth and light traveling at 300,000 kilometers per second, simply dividing one number by the other (distance by speed) gives us an approximate time of 500 seconds, or 8 minutes and 20 seconds. Particles that reach Earth within those few minutes take millions of years to travel from the Sun's core to its surface.

The Sun moves in its orbit at a speed of 220 kilometers per second. The Sun is located almost on the outskirts of the Milky Way, 24,000-26,000 light-years from the center of the galaxy, and therefore takes 225-250 million years to complete one orbit around the center of the Milky Way.

The distance from the Sun to the Earth varies throughout the year. Because the Earth moves in an elliptical orbit around the Sun, the distance between these celestial bodies varies from 147 to 152 million kilometers. The average distance between the Earth and the Sun is called an astronomical unit (AU).

The pressure at the Sun's core is 340 billion times greater than atmospheric pressure at the Earth's surface.

The diameter of the Sun is equivalent to 109 times the diameter of the Earth.

The surface area of ​​the Sun is equivalent to 11,990 times the surface of the Earth.

If the Sun were the size of a football, Jupiter would be the size of a golf ball, and the Earth would be the size of a pea.

The force of gravity on the surface of the Sun is 28 times greater than on Earth. Therefore, a person who weighs 60 kg on Earth will weigh 1680 kg on the Sun. Simply put, we will be crushed by our own weight.

Light from the Sun reaches Pluto's surface in 5.5 hours.

The Sun's closest neighbor is the star Proxima Centauri. It is located 4.3 light years away.

Approximately a trillion solar neutrinos are passing through your body as you read this sentence.

The brightness of the Sun is equivalent to the brightness of 4 trillion trillion 100-watt light bulbs.

An area of ​​the Sun's surface the size of a postage stamp has the light of 1.5 million candles.

The amount of energy reaching the surface of our planet is 6000 times greater than the energy demand of people around the world.

The Earth receives 94 billion megawatts of energy from the Sun. This is 40,000 times the annual requirement of the United States.

The total amount of fossil fuels on planet Earth is equivalent to 30 solar days.

A total solar eclipse lasts a maximum of 7 minutes and 40 seconds.

There are about 4-5 solar eclipses per year.

Physical characteristics of the Sun

The beautiful symmetry of a total solar eclipse occurs because the Sun is 400 times larger than the Moon, but also 400 times farther from the Earth, making the 2 bodies the same across in size in the sky.

The full size of the Sun could accommodate 1.3 million Earth-sized planets.

99.86% of the total mass of the Solar System is concentrated in the Sun. The mass of the Sun is 1,989,100,000,000,000,000,000 billion kg, or 333,060 times the mass of the Earth.

The temperature inside the Sun can reach 15 million degrees Celsius. At the Sun's core, energy is generated by nuclear fusion as hydrogen turns into helium. Since hot objects tend to expand, the Sun would explode like a giant bomb if it weren't for its enormous gravitational force. The temperature on the surface of the Sun is closer to 5600 degrees Celsius.

The Earth's core is almost as hot as the surface of the Sun, which is approximately 5600 degrees Celsius. Colder are certain areas called sunspots (3,800°C).

Different parts of the Sun rotate at different speeds. Unlike regular planets, the Sun is a large ball of incredibly hot hydrogen gas. Due to its mobility, different parts of the Sun rotate at different speeds. To see how quickly a surface rotates, you need to observe the movement of sunspots relative to its surface. Spots at the equator take 25 Earth days to complete one rotation, while spots at the poles complete a rotation in 36 days.

The Sun's outer atmosphere is hotter than its surface. The surface of the Sun reaches a temperature of 6000 degrees Kelvin. But it's actually much smaller than the Sun's atmosphere. Above the surface of the Sun is a region of the atmosphere called the chromosphere, where temperatures can reach 100,000 Kelvin. But that doesn't mean anything. There's an even more distant region called the coronal region, which extends to a volume even larger than the Sun itself. Temperatures in the corona can reach 1 million Kelvin.

Inside the Sun, where thermonuclear reactions occur, the temperature reaches an incredible 15 million degrees.

The Sun is an almost perfect sphere with a difference of only 10 km in diameter between the poles and the equator. The average radius of the Sun is 695,508 km (109.2 x Earth's radius).

In terms of magnitude, it is classified as a yellow dwarf (G2V).

The diameter of the Sun is 1,392,684 kilometers.

The sun has a very strong magnetic field. Solar flares occur when energetic streams of charged particles are released by the Sun during magnetic storms, which we see as sunspots. In sunspots, the magnetic lines are twisted and they rotate, just like tornadoes on Earth.

Does water exist on the Sun? Quite a strange question... After all, we know that there is a lot of hydrogen in the Sun, the main element of water, but in order for there to be water, a chemical element such as oxygen is also needed. Not long ago, an international group of scientists discovered that the Sun is water (specifically, water vapor).

The sun in history

Ancient cultures built stone monuments or modified rocks to mark the movements of the Sun and Moon, the changing seasons, created calendars and calculated eclipses.

Despite the correct thinking of some ancient Greek thinkers, many believed that the Sun revolved around the Earth, starting with the ancient Greek scientist Ptolemy introducing the "geocentric" model in 150 BC.

It was not until 1543 that Nicolaus Copernicus described a heliocentric, sun-centered model of the solar system, and in 1610, Galileo Galilei's discovery of the moons of Jupiter showed that not all celestial bodies orbit the Earth.

Solar Research

In 1990, NASA and the European Space Agency launched the Ulysses probe to take the first images of the polar regions of the Sun. In 2004, NASA's Genesis spacecraft brought samples of solar wind back to Earth for study.

The most famous spacecraft (launched in December 1995) that observes the Sun is the Solar and Heliospheric Observatory SOHO, built by NASA and ESA, and continuously monitors the luminary, sending countless photographs back to Earth. It was created to study the solar wind, as well as the outer layers of the Sun and its internal structure. It has imaged the structure of sunspots below the surface, measured the acceleration of the solar wind, detected coronal waves and solar tornadoes, detected more than 1,000 comets, and enabled more accurate space weather predictions.

A more recent NASA mission is the STEREO spacecraft. These are two spacecraft launched in October 2006. They were designed to view activity on the Sun simultaneously from two different vantage points to recreate a three-dimensional perspective of solar activity, allowing astronomers to better predict space weather.

The sun vibrates due to a set of acoustic waves, like a bell. If our vision were sharp enough, we could see the vibrations spreading along the surface of its disk, creating intricate patterns. Astronomers from Stanford University have carefully studied the movements on the surface of the Sun. Solar sound waves typically have a very low vibration frequency that cannot be detected by the human ear. In order to be able to hear, scientists amplified them 42,000 times and pressed for a few seconds of waves measured over 40 days.

Alexander Kosovichev, team leader and member of the Stanford solar oscillation team, has found a simple way to convert data from equipment that measures the vertical motion of the sun's surface into sound. Stephen Taylor, a professor of music at the University of Illinois, composed the music for this video and sounds.

The team used a new method to calculate the spectrum of water at sunspot temperatures. In their research since 1995, the team has documented the presence of water - not in liquid form, of course, but in a vapor state - in the dark areas of sunspots. Scientists compared the infrared spectrum of hot water with sunspots.

Water in sunspots causes something like a "stellar greenhouse effect" and affects the release of energy from the sunspots. Hot water molecules also absorb infrared radiation most strongly in the atmosphere of cold stars.

Sunspots and flares

Since 1610, Galileo Galilei was the first in Europe to observe the Sun using his telescope, thereby laying the foundation for regular studies of sunspots and the solar cycle, which have continued for over four centuries. 140 years later, in 1749, one of the oldest observatories in Europe, located in the Swiss city of Zurich, began making daily observations of sunspots, first by simply counting and sketching them, and later by taking photographs of the Sun. Currently, many solar stations continuously observe and record all changes on the surface of the Sun.

The most famous period of change of the Sun is the eleven-year solar cycle, during which the luminary passes through a minimum and maximum of its activity.

The solar cycle is most often determined by the number of sunspots on the photosphere, which is characterized by a special index - the Wolf number. This index is calculated as follows. First, the number of sunspot groups is counted, then this number is multiplied by 10 and the number of individual sunspots is added to it. A factor of 10 roughly corresponds to the average number of spots in one group; In this way, it is possible to fairly accurately estimate the number of sunspots even in cases where poor observing conditions do not allow direct counting of all small sunspots. Below are the results of such calculations over a huge period of time, starting in 1749. They clearly show that the number of sunspots on the Sun changes periodically, forming a cycle of solar activity with a period of about 11 years.

Currently, there are at least 2 organizations that independently of each other conduct continuous observations of the solar cycle and count the number of spots on the Sun. The first is the Sunspot Index Data Center in Belgium, where the so-called International Sunspot Number is determined. It is this number (and its standard deviation DEV) that is shown in the table already given above. In addition, the number of spots is counted by the US National Oceanic and Atmospheric Administration. The number of sunspots determined here is called the NOAA sunspot number.

The earliest observations of sunspots at the end of the 17th century, that is, at the dawn of the era of systematic research, showed that the Sun at that time was passing through a period of extremely low activity. This period was called the Maunder Minimum, which lasted almost a century, from 1645 to 1715. Although observations of those times were not carried out as carefully and systematically as modern ones, nevertheless, the passage of the solar cycle through a very deep minimum is considered reliably established by the scientific world. The period of extremely low solar activity corresponds to a special climatic period in the history of the Earth, which is called the “Little Ice Age”.

Everything that happens on the Sun greatly affects our planet and people, but there are two explosive solar events that affect us the most. One of them is solar flares, where radiation waves of tens of millions of degrees suddenly burst through a small area on the surface of the Sun, which can damage telecommunications and satellites. Another type of phenomenon is a coronal mass ejection, where billions of tons of charged particles of energy are ejected from the solar corona at speeds of millions of kilometers per hour. When these massive clouds enter Earth's protective magnetosphere, they compress magnetic field lines and dump millions of trillions of watts of power into the upper atmosphere. This leads to overloads on power lines, resulting in blackouts and damage to all sensitive equipment and all objects in orbit around the Earth.

Often these two phenomena occur together, as was the case in October 2003. Thanks to modern measuring instruments, such an event can be detected at an early stage and allows the necessary measures to be taken.

Analysis of SOHO and Yohkoh data showed that giant X-ray loops in the hot solar corona provide important magnetic connections between sunspots and the Sun's magnetic poles. These giant loops are approximately 500,000 miles long and are filled with 3.5 million F of hot, electrified gas. They appear in the growth phase of the 11-year sunspot cycle and are associated with the release of energy from the spots, which occurs every 1-1.5 years and causes a cyclic reversal of the magnetic poles of the Sun. These compounds are thought to play an important role in the "solar dynamo" - a process that produces the Sun's strong magnetic fields and is the source of sunspots, solar flares and mass ejections that impact Earth.

Spot activity increases from a minimum to a maximum for about 11 years. Those. after 22 years a new cycle begins. During this time, the entire magnetic field of the Sun changes - the north pole becomes the south and vice versa; then switch places again in the next cycle.

The sun's surface is covered in bubbles the size of Texas. Granules are parts of plasma with a short lifetime of heat transferred by convection to the surface, like water bubbles in a boiling water surface. The rise and fall of the bubbles produces sound waves that cause sounds to be emitted every 5 minutes.

The most powerful geomagnetic storm in the entire history of observations was the geomagnetic storm of 1859. A complex of events, including both the geomagnetic storm and the powerful active phenomena on the Sun that caused it, is sometimes called the “Carrington Event”, which in the literature is called the “Solar Superstorm”.

The most powerful magnetic storm observed by mankind was in August 1972. It was fast, intense and large, but the most important thing that turned it into a historical phenomenon was the polarization of its magnetic field - opposite to the Earth. When its magnetic field hits the Earth's magnetic field, the two fields combine and send a huge stream into the upper atmosphere. Electrical equipment, telegraphs, and telecommunications were disabled in large parts of Europe and America.

The proton storm was strongest in 1989. It was especially saturated with high acceleration protons, covered with 100 million electron volts of energy. Such protons can penetrate an 11 cm hole in water.

Other facts about the Sun

Only 55% of all American adults know that the Sun is a star.

Exercising in the sun increases energy and calorie expenditure.

According to the proverb, those born at dawn will be smart, but those born at sunset will be lazy.

Heliotherapy is one of the oldest and most accessible methods of treating human ailments. No wonder they say that where the sun comes, diseases go away.

According to research, the sun's rays act on specific receptors in the human retina, which sends a signal to the brain to produce more serotonin. And, as we all know, this is the hormone of happiness.

Just 15 minutes of daily sun exposure is enough to force the body to produce the required amount of vitamin E, which is vital for our body.

Skin pigmentation protects the deeper layers of the body from exposure to ultraviolet rays.

The color of the sky depends primarily on layers of air pollution, such as smoke or dust. The normal color of the sky is blue due to the refraction of sunlight by atmospheric hydrogen.

Red sunsets are caused by heavy pollution in the atmosphere. When sunlight passes through the atmosphere, the layers of rays with shorter wavelengths retain and absorb only the rays with longer wavelengths that pass through the atmosphere, which are red, orange and yellow rays. Large amounts of dust and dirt even stop the yellow light and only the red cross.

The red sky is observed especially well during volcanic eruptions.

The Sun is the only star in the Solar System; all the planets of the system, as well as their satellites and other objects, including cosmic dust, move around it. If we compare the mass of the Sun with the mass of the entire solar system, it will be about 99.866 percent.

The Sun is one of the 100,000,000,000 stars in our Galaxy and is the fourth largest among them. The closest star to the Sun, Proxima Centauri, is located four light years from Earth. The distance from the Sun to planet Earth is 149.6 million km; light from a star reaches in eight minutes. The star is located at a distance of 26 thousand light years from the center of the Milky Way, while it rotates around it at a speed of 1 revolution every 200 million years.

Presentation: Sun

According to the spectral classification, the star is a “yellow dwarf” type; according to rough calculations, its age is just over 4.5 billion years, it is in the middle of its life cycle.

The sun, consisting of 92% hydrogen and 7% helium, has a very complex structure. At its center there is a core with a radius of approximately 150,000-175,000 km, which is up to 25% of the total radius of the star; at its center the temperature approaches 14,000,000 K.

The core rotates around its axis at high speed, and this speed significantly exceeds the outer shells of the star. Here, the reaction of helium formation from four protons occurs, resulting in a large amount of energy passing through all layers and emitted from the photosphere in the form of kinetic energy and light. Above the core there is a zone of radiative transfer, where temperatures are in the range of 2-7 million K. This is followed by a convective zone approximately 200,000 km thick, where there is no longer re-radiation for energy transfer, but plasma mixing. At the surface of the layer the temperature is approximately 5800 K.

The atmosphere of the Sun consists of the photosphere, which forms the visible surface of the star, the chromosphere, which is about 2000 km thick, and the corona, the last outer shell of the sun, the temperature of which is in the range of 1,000,000-20,000,000 K. From the outer part of the corona, ionized particles called the solar wind emerge. .

When the Sun reaches an age of approximately 7.5 - 8 billion years (that is, in 4-5 billion years), the star will turn into a “red giant”, its outer shells will expand and reach the Earth’s orbit, possibly pushing the planet further away.

Under the influence of high temperatures, life as we understand it today will simply become impossible. The Sun will spend the final cycle of its life in the “white dwarf” state.

The sun is the source of life on Earth

The sun is the most important source of heat and energy, thanks to which, with the assistance of other favorable factors, there is life on Earth. Our planet Earth rotates around its axis, so every day, being on the sunny side of the planet, we can watch the dawn and the amazingly beautiful phenomenon of sunset, and at night, when part of the planet falls into the shadow side, we can watch the stars in the night sky.

The sun has a huge impact on the life of the Earth; it participates in photosynthesis and helps in the formation of vitamin D in the human body. The solar wind causes geomagnetic storms and it is its penetration into the layers of the earth's atmosphere that causes such a beautiful natural phenomenon as the northern lights, also called the polar lights. Solar activity changes towards decreasing or increasing approximately every 11 years.

Since the beginning of the space age, researchers have been interested in the Sun. For professional observation, special telescopes with two mirrors are used, international programs have been developed, but the most accurate data can be obtained outside the layers of the Earth’s atmosphere, so most often research is carried out from satellites and spacecraft. The first such studies were carried out back in 1957 in several spectral ranges.

Today, satellites are launched into orbit, which are observatories in miniature, making it possible to obtain very interesting materials for studying the star. Even during the years of the first human space exploration, several spacecraft were developed and launched aimed at studying the Sun. The first of these were a series of American satellites, launched in 1962. In 1976, the West German Helios-2 apparatus was launched, which for the first time in history approached the luminary at a minimum distance of 0.29 AU. At the same time, the appearance of light helium nuclei during solar flares was recorded, as well as magnetic shock waves covering the range of 100 Hz-2.2 kHz.

Another interesting device is the Ulysses solar probe, launched in 1990. It is launched into a near-solar orbit and moves perpendicular to the ecliptic strip. 8 years after launch, the device completed its first orbit around the Sun. He recorded the spiral shape of the luminary's magnetic field, as well as its constant increase.

In 2018, NASA plans to launch the Solar Probe+ apparatus, which will approach the Sun at the closest possible distance - 6 million km (this is 7 times less than the distance reached by Helius-2) and will occupy a circular orbit. To protect against extreme temperatures, it is equipped with a carbon fiber shield.