Eclipses are among the most spectacular astronomical phenomena. However, no technical means can fully convey the sensations arising from the observer. And yet, due to the imperfection of the human eye, he does not see everything at once. The details of this wonderful picture, eluding the eye, can only be revealed and captured by a special technique of photographing and signal processing. The variety of eclipses is far from exhausted by the phenomena in the Sun-Earth-Moon system. Relatively close space bodies regularly cast shadows on each other (it is only necessary that there is some powerful source of light radiation nearby). Watching this cosmic shadow theater, astronomers get a lot of interesting information about the structure of the universe. Photo Vyacheslav Khondyrev

In the Bulgarian resort of Shabla, August 11, 1999 was the most ordinary summer day. Blue sky, golden sand, warm gentle sea. But no one went into the water on the beach - the public was preparing for observations. It was here that a hundred-kilometer spot of the lunar shadow should have crossed the Black Sea coast, and the duration of the full phase, according to calculations, reached 3 minutes 20 seconds. The excellent weather quite corresponded to long-term data, but everyone looked with alarm at the cloud hanging over the mountains.

In fact, the eclipse was already underway, just few people were interested in its partial phases. Another thing is the full phase, before the start of which there was still half an hour. A brand new digital SLR, specially bought for this occasion, was in full readiness. Everything is thought out to the smallest detail, each movement is rehearsed dozens of times. The weather would not have time to deteriorate, and yet, for some reason, anxiety was growing. Maybe the fact is that the light has noticeably diminished and it has become sharply colder? But this is how it should be with the approach of the full phase. However, the birds do not understand this - all the birds capable of flying rose into the air and shouted out circles above our heads. The wind blew from the sea. Every minute he grew stronger, and the heavy camera began to tremble on a tripod, which until recently seemed so reliable.

There is nothing to do - a few minutes before the calculated moment, at the risk of spoiling everything, I went down from the sandy hill to its foot, where the bushes extinguished the wind. A few movements, and literally at the last moment the technique is again set up. But what is this noise? Dogs bark and howl, sheep bleat. It seems that all animals capable of making sounds do it as if for the last time! The light is fading every second. Birds in the darkened sky are no longer visible. Everything subsides at once. The filamentous crescent of the sun illuminates the seashore no brighter than the full moon. Suddenly, he goes out. Who followed him in the last seconds without a dark filter, in the first moments, he probably does not see anything.

My fussy excitement was replaced by a real shock: the eclipse, which I dreamed of all my life, has already begun, precious seconds are flying, and I can’t even raise my head and enjoy the rarest spectacle - photography comes first! Each time the button is pressed, the camera automatically takes a series of nine shots (in “bracketing” mode). One more. More and more. While the camera clicks the shutter, I still dare to break away and look at the crown through binoculars. From the black moon, many long rays scattered in all directions, forming a pearly crown with a yellowish-cream tint, and bright pink prominences flash at the very edge of the disk. One of them flew unusually far from the edge of the moon. Diverging to the sides, the rays of the crown gradually turn pale and merge with the dark blue background of the sky. The effect of presence is such that I am not standing on the sand, but flying in the sky. And time seemed to disappear...

Suddenly, a bright light hit my eyes - it was the edge of the Sun that floated out from behind the Moon. How quickly it all ended! Prominences and rays of the corona are visible for a few more seconds, and the shooting continues until the last. The program is done! A few minutes later, the day flares up again. The birds immediately forgot the fright from the extraordinary fleeting night. But for many years my memory has kept a feeling of the absolute beauty and grandeur of the cosmos, a feeling of belonging to its mysteries.

How was the speed of light measured for the first time?

Eclipses occur not only in the Sun-Earth-Moon system. For example, the four largest moons of Jupiter, discovered by Galileo Galilei in 1610, played an important role in the development of navigation. In that era, when there were no accurate marine chronometers, it was possible to find out the Greenwich time, which was necessary to determine the longitude of the ship, far from their native shores. Eclipses of satellites in the Jupiter system occur almost every night, when one or the other satellite enters the shadow cast by Jupiter, or hides from our view behind the disk of the planet itself. Knowing the pre-calculated moments of these phenomena from the marine almanac and comparing them with the local time obtained from elementary astronomical observations, one can determine one's longitude. In 1676, the Danish astronomer Ole Christensen Römer noticed that the eclipses of Jupiter's moons deviated slightly from the predicted moments. The Jupiter clock either went ahead by a little over eight minutes, then, after about six months, it lagged behind by the same amount. Roemer compared these fluctuations with the position of Jupiter relative to the Earth and came to the conclusion that the whole point is in the delay in the propagation of light: when the Earth is closer to Jupiter, eclipses of its satellites are observed earlier, when further away, later. The difference, which was 16.6 minutes, corresponded to the time for which the light traveled the diameter of the earth's orbit. So Roemer measured the speed of light for the first time.

Encounters in Heavenly Knots

By an amazing coincidence, the apparent sizes of the Moon and the Sun are almost the same. Thanks to this, in rare minutes of total solar eclipses, you can see prominences and the solar corona - the outermost plasma structures of the solar atmosphere, constantly “flying away” into outer space. If the Earth had not had such a large satellite, for the time being, no one would have guessed about their existence.

The visible paths across the sky of the Sun and the Moon intersect at two points - the nodes through which the Sun passes about once every six months. It is at this time that eclipses become possible. When the Moon meets the Sun at one of the nodes, a solar eclipse occurs: the top of the cone of the lunar shadow, resting against the surface of the Earth, forms an oval shadow spot, which moves at high speed along the earth's surface. Only people who get into it will see the lunar disk, completely covering the sun. For an observer of the total phase band, the eclipse will be partial. Moreover, in the distance it may not even be noticed - after all, when less than 80-90% of the solar disk is covered, the decrease in illumination is almost imperceptible to the eye.

The width of the total phase band depends on the distance to the Moon, which, due to the ellipticity of its orbit, varies from 363 to 405 thousand kilometers. At the maximum distance, the cone of the lunar shadow does not reach the surface of the Earth a little. In this case, the visible dimensions of the Moon turn out to be slightly smaller than the Sun, and instead of a total eclipse, an annular eclipse occurs: even in the maximum phase, a bright rim of the solar photosphere remains around the Moon, preventing you from seeing the corona. Astronomers, of course, are primarily interested in total eclipses, in which the sky darkens so much that a radiant corona can be observed.

Lunar eclipses (from the point of view of a hypothetical observer on the Moon they would, of course, be solar) occur during a full moon when our natural satellite passes the node opposite to where the Sun is and enters the cone of shadow cast by the Earth. There is no direct sunlight inside the shadow, but the light refracted in the earth's atmosphere still hits the moon's surface. It usually paints it in a reddish (and sometimes brown-greenish) color due to the fact that in the air long-wave (red) radiation is absorbed less than short-wave (blue). One can imagine what horror the suddenly darkened, ominously red disk of the Moon inspired in primitive man! What can we say about solar eclipses, when the daylight, the main deity for many peoples, suddenly began to disappear from the sky?

It is not surprising that the search for patterns in the order of eclipses became one of the first difficult astronomical tasks. Assyrian cuneiform tablets dating back to 1400-900 BC. e., contain data on systematic observations of eclipses in the era of the Babylonian kings, as well as a mention of a remarkable period of 65851/3 days (saros), during which the sequence of lunar and solar eclipses is repeated. The Greeks went even further - according to the shape of the shadow creeping on the Moon, they concluded that the Earth is spherical and that the Sun is much larger than it.

How masses of other stars are determined

Alexander Sergeev

Six hundred "sources"

With distance from the Sun, the outer corona gradually fades. Where in the photographs it merges with the sky background, its brightness is a million times less than the brightness of the prominences and the inner corona surrounding them. At first glance, it is impossible to photograph the corona along its entire length from the edge of the solar disk to merging with the sky background, because it is well known that the dynamic range of photographic matrices and emulsions is thousands of times smaller. But the pictures that this article illustrates prove otherwise. The problem has a solution! Only you need to go to the result not straight ahead, but around: instead of one “ideal” frame, you need to take a series of shots with different exposures. Different images will reveal regions of the corona at different distances from the Sun.

Such images are first processed separately, and then combined with each other according to the details of the rays of the corona (images cannot be combined along the Moon, because it is moving rapidly relative to the Sun). Digital photo processing is not as easy as it seems. However, our experience shows that any images of one eclipse can be brought together. Wide-angle with telephoto, short and long exposure, professional and amateur. In these pictures, there are pieces of the work of twenty-five observers who photographed the eclipse of 2006 in Turkey, the Caucasus and Astrakhan.

Six hundred original images, having undergone many transformations, turned into just a few separate images, but what! Now they have all the smallest details of the corona and prominences, the chromosphere of the Sun and stars up to the ninth magnitude. Such stars, even at night, are only visible through good binoculars. The rays of the corona "worked" up to a record 13 radii of the solar disk. And more color! Everything that is visible in the final images has a real color that matches the visual sensations. And this was achieved not by artificial coloring in Photoshop, but by using strict mathematical procedures in the processing program. The size of each image approaches a gigabyte - you can make prints up to one and a half meters wide without any loss of detail.

How to refine the orbits of asteroids

Eclipsing variable stars are close binary systems in which two stars revolve around a common center of mass so that the orbit is turned edge-on towards us. Then the two stars regularly outshine each other, and the earthly observer sees periodic changes in their total brightness. The most famous eclipsing variable star is Algol (beta Perseus). The circulation period in this system is 2 days 20 hours and 49 minutes. During this time, two minima are observed on the light curve. One deep, when the small but hot white star Algol A is completely hidden behind the dim red giant Algol B. At this time, the total brightness of the binary star drops by almost 3 times. A less noticeable decrease in brightness, by 5–6%, is observed when Algol A passes against the background of Algol B and slightly weakens its brightness. A careful study of the light curve reveals a lot of important information about a star system: the size and luminosity of each of the two stars, the degree of elongation of their orbit, the deviation of the shape of stars from spherical under the influence of tidal forces, and most importantly, the masses of stars. Without this information, it would be difficult to create and test a modern theory of the structure and evolution of stars. Stars can be eclipsed not only by stars, but also by planets. When the planet Venus passed across the disk of the Sun on June 8, 2004, few people thought of talking about an eclipse, since the tiny dark speck of Venus had almost no effect on the brilliance of the Sun. But if a gas giant like Jupiter were to take its place, it would obscure about 1% of the area of ​​the solar disk and reduce its brightness by the same amount. This can already be registered with modern instruments, and today there are already cases of such observations. And some of them are made by amateur astronomers. In fact, "exoplanetary" eclipses are the only way available to amateurs to observe planets around other stars.

Alexander Sergeev

Panorama in the moonlight

The extraordinary beauty of a solar eclipse is not limited to the sparkling crown. After all, there is also a glowing ring along the entire horizon, which creates a unique illumination at the moment of the full phase, as if the sunset occurs from all sides of the world at once. But few people manage to take their eyes off the crown and look at the amazing colors of the sea and mountains. This is where panoramic photography comes in. Several shots joined together will show everything that escaped the eye or did not cut into memory.

The panoramic shot in this article is special. Its horizontal coverage is 340 degrees (almost a full circle), and vertically almost to the zenith. Only on it we later examined cirrus clouds, which almost spoiled our observations - they are always a change in the weather. And indeed, the rain began within an hour after the Moon descended from the disk of the Sun. The contrails of the two planes visible in the picture do not actually break off in the sky, but simply go into the moon's shadow and become invisible because of this. On the right side of the panorama, the eclipse is in full swing, and on the left side of the image, the full phase has just ended.

To the right and below the crown is Mercury - it never goes far from the Sun, and not everyone can see it. Even lower sparkles Venus, and on the other side of the Sun - Mars. All the planets are located along one line - the ecliptic - the projection onto the sky of the plane, near which all the planets revolve. Only during an eclipse (and also from space) is it possible to see our planetary system surrounding the Sun from an edge like this. In the central part of the panorama, the constellations Orion and Auriga are visible. The bright stars Capella and Rigel are white, while the red supergiant Betelgeuse and Mars are orange (the color is visible when magnified). Hundreds of people who watched the eclipse in March 2006 now feel like they saw it all with their own eyes. But the panoramic shot helped them - it is already posted on the Internet.

How should you take pictures?

On March 29, 2006, in the village of Kemer on the Mediterranean coast of Turkey, in anticipation of the beginning of a total eclipse, experienced observers shared secrets with beginners. The most important thing at an eclipse is not to forget to open the lenses. This is not a joke, this really happens. And you should not duplicate each other, making the same frames. Let everyone shoot what exactly with his equipment can turn out better than others. For observers armed with wide-angle cameras, the main target is the outer corona. We must try to take a series of pictures of her with different shutter speeds. Telephoto owners can get detailed images of the middle corona. And if you have a telescope, then you need to photograph the area at the very edge of the lunar disk and not waste precious seconds working with other equipment. And the call was then heard. And immediately after the eclipse, observers began to freely exchange files with images in order to assemble a set for further processing. This later led to the creation of a bank of original images from the 2006 eclipse. Everyone now understood that from the original images to a detailed image of the entire crown is still very, very far away. The times when any sharp picture of an eclipse was considered a masterpiece and the final result of observations are irrevocably gone. Upon returning home, everyone was waiting for work at the computer.

active sun

The Sun, like other stars similar to it, is distinguished by periodically occurring states of activity, when many unstable structures arise in its atmosphere as a result of complex interactions of a moving plasma with magnetic fields. First of all, these are sunspots, where part of the thermal energy of the plasma is converted into the energy of the magnetic field and into the kinetic energy of the movement of individual plasma flows. Sunspots are cooler than their surroundings and appear darker against the background of the brighter photosphere, the layer of the Sun's atmosphere from which most of our visible light comes. Around the spots and throughout the active region, the atmosphere, additionally heated by the energy of damped magnetic fields, becomes brighter, and structures called torches (visible in white light) and flocculi (observed in monochromatic light of individual spectral lines, for example, hydrogen) appear.

Above the photosphere are more rarefied layers of the solar atmosphere 10-20 thousand kilometers thick, called the chromosphere, and above it the corona extends for many millions of kilometers. Above groups of sunspots, and sometimes even away from them, extended clouds often appear - prominences, clearly visible during the total phase of the eclipse on the edge of the solar disk in the form of bright pink arcs and emissions. The corona is the rarefied and very hot part of the Sun's atmosphere, which, as it were, evaporates into the surrounding space, forming a continuous stream of plasma moving away from the Sun, called the solar wind. It is he who gives the solar corona a radiant appearance that justifies its name.

From the motion of matter in the tails of comets, it turned out that the speed of the solar wind gradually increases with distance from the Sun. Moving away from the sun by one astronomical unit (the radius of the earth's orbit), the solar wind "flies" at a speed of 300-400 km / s at a particle concentration of 1-10 protons per cubic centimeter. Encountering obstacles in the form of planetary magnetospheres on its way, the solar wind flow forms shock waves that affect the atmospheres of planets and the interplanetary medium. By observing the solar corona, we obtain information about the state of space weather in outer space around us.

The most powerful manifestations of solar activity are plasma explosions called solar flares. They are accompanied by strong ionizing radiation, as well as powerful ejections of hot plasma. Passing through the corona, plasma flows noticeably affect its structure. For example, helmet-shaped formations are formed in it, turning into long rays. In fact, these are elongated tubes of magnetic fields, along which streams of charged particles propagate at high speeds (mainly energetic protons and electrons). In fact, the visible structure of the solar corona reflects the intensity, composition, structure, direction of movement and other characteristics of the solar wind, which constantly affects our Earth. During flashes, its speed can reach 600-700, and sometimes more than 1000 km/s.

In the past, the corona was observed only during total solar eclipses and only near the Sun. In total, about an hour of observations accumulated. With the invention of the non-eclipsing coronograph (a special telescope in which an artificial eclipse is arranged), it became possible to constantly monitor the inner regions of the corona from the Earth. It is also always possible to register the radio emission of the corona, even through clouds and at great distances from the Sun. But in the optical range, the outer regions of the corona are still visible from the Earth only in the total phase of a solar eclipse.

With the development of extra-atmospheric research methods, it became possible to directly image the entire corona in ultraviolet and X-rays. The most impressive images regularly come from the space-based SOHO Solar Orbital Heliospheric Observatory, launched in late 1995 by the joint efforts of the European Space Agency and NASA. In the SOHO images, the rays of the corona are very long, and many stars are visible. However, in the middle, in the region of the inner and middle crown, the image is missing. The artificial "moon" in the coronograph is too big and obscures much more than the real one. But it is impossible otherwise - the Sun shines too brightly. So satellite imagery does not replace observations from Earth. But space and terrestrial images of the solar corona complement each other perfectly.

SOHO also constantly monitors the surface of the Sun, and eclipses are not a hindrance to it, because the observatory is located outside the Earth-Moon system. Several ultraviolet images taken by SOHO around the total phase of the 2006 eclipse have been pieced together and placed in place of the image of the Moon. Now we can see which active regions in the atmosphere of the star closest to us are associated with certain features in its corona. It may seem that some "domes" and zones of turbulence in the corona are not caused by anything, but in reality their sources are simply hidden from observation on the other side of the star.

"Russian" eclipse

The next total solar eclipse is already being called “Russian” in the world, since it will be mainly observed in our country. On the afternoon of August 1, 2008, the full phase band will stretch from the Arctic Ocean almost along the meridian to Altai, passing exactly through Nizhnevartovsk, Novosibirsk, Barnaul, Biysk and Gorno-Altaisk - right along the federal highway M52. By the way, this will be the second eclipse in Gorno-Altaisk in a little over two years - it is in this city that the eclipse bands of 2006 and 2008 intersect. During the eclipse, the Sun's height above the horizon will be 30 degrees, which is enough to photograph the corona and ideal for panoramic shooting. The weather in Siberia at this time is usually good. It's not too late to get a couple of cameras ready and buy a plane ticket.

This eclipse is not to be missed. The next total eclipse will be visible in China in 2009, and then good conditions for observations will develop only in the United States in 2017 and 2024. In Russia, the break will last almost half a century - until April 20, 2061.

If you get together, then here's a good piece of advice for you: observe in groups and share the received images, send them for joint processing to the Flower Observatory: www.skygarden.ru. Then someone will definitely be lucky with the processing, and then everyone, even those who stay at home, thanks to you, will see the eclipse of the Sun - a star crowned with a crown.

Under the influence of gravity, S., like any star, tends to shrink. This compression is counteracted by the pressure drop resulting from the high temperature and density of the internal. layers C. In the center of C. temperature T ≈ 1.6. 10 7 K, density ≈ 160 gcm -3 . Such a high temperature in the central regions of S. can be maintained for a long time only by the synthesis of helium from hydrogen. These reactions and yavl. main source of energy C.

At temperatures ~10 4 K (chromosphere) and ~10 6 (corona), as well as in the transition layer with intermediate temperatures, ions of various elements appear. The emission lines corresponding to these ions are quite numerous in the short-wavelength region of the spectrum (λ< 1800 . Спектр в этой области состоит из отдельных эмиссионных линий, самые яркие из к-рых - линия водорода L a (1216 ) и линия нейтрального (584 ) и ионизованного (304 ) гелия. Излучение в этих линиях выходит из области эмиссии практически не поглощаясь. Излучение в радио- и рентг. областях сильно зависит от степени солнечной активности, увеличиваясь или уменьшаясь в несколько раз в течение 11-летнего и заметно возрастая при вспышках на Солнце.

Phys. characteristics of different layers are shown in fig. 5 (the lower chromosphere with a thickness of ≈ 1500 km, where the gas is more homogeneous, is conventionally distinguished). The heating of the upper atmosphere of S. - the chromosphere and the corona - may be due to mechanical. the energy carried by the waves arising in the upper part of the convective zone, as well as the dissipation (absorption) of electrical energy. currents generated by the magnet. fields moving along with convective currents.

The existence of a surface convective zone in the north is responsible for a number of other phenomena. Cells of the uppermost tier of the convective zone are observed on the surface of S. in the form of granules (see). Deeper large-scale motions in the second tier of the zone appear as supergranulation cells and a chromospheric network. There are reasons to believe that convection in an even deeper layer is observed in the form of giant structures - cells with larger dimensions than supergranulation.

Large local magnets. fields in the zone ± 30 o from the equator lead to the development of the so-called. active regions with spots included in them. The number of active regions, their position on the disk, and the polarities of sunspots in groups change with a period of ≈ 11.2 years. During the period of an unusually high maximum in 1957-58. activity affected almost the entire solar disk. In addition to strong local fields, there is a weaker large-scale magnetic field in the north. field. This field changes sign with a period of approx. 22 years and near the poles vanishes at maximum solar activity.

With a large flash, enormous energy is released, ~10 31 -10 32 erg (power ~10 29 erg/s). It is drawn from the energy of the magnet. hotspot fields. According to ideas, to-rye have been successfully developing since the 1960s. in the USSR, the interaction of magnetic fluxes gives rise to current sheets. Development in the current sheet can lead to acceleration of particles, and there are trigger (starting) mechanisms that lead to the sudden development of the process.

Rice. 13. Types of impact of a solar flare on the Earth (according to D. X. Menzel).

X-ray radiation and solar cosmic rays coming from the flare (Fig. 13) cause additional ionization of the earth's ionosphere, which affects the propagation conditions of radio waves. The flow of particles ejected during the flare reaches the Earth's orbit in about a day and causes a magnetic storm and auroras on Earth (see , ).

In addition to corpuscular flows generated by flares, there is continuous corpuscular radiation C. It is associated with the outflow of rarefied plasma from the external. areas of the solar corona into interplanetary space - the solar wind. Losses of matter due to the solar wind are small, ≈ 3 . 10 -14 per year, but it represents the main. component of the interplanetary medium.

The solar wind carries a large-scale magnetic field into interplanetary space. field C. The rotation of C. twists the lines of the interplanetary magnetic field. field (IMF) into the Archimedean spiral, which is clearly observed in the plane of the ecliptic. Since the main a feature of a large-scale magnet. fields of S. yavl. two circumpolar regions of opposite polarity and fields adjacent to them, with calm S. the northern hemisphere of interplanetary space is filled with a field of one sign, the southern - of another (Fig. 14). Near the maximum activity, due to a change in the sign of the large-scale solar field, this regular magnetic field is reversed. fields of interplanetary space. Magn. the flows of both hemispheres are separated by a current sheet. With the rotation of S. the Earth is several. days, now above, now below the curved "corrugated" surface of the current sheet, i.e., it enters the IMF, directed now towards the north, now away from it. This phenomenon is called interplanetary magnetic field.

Near the activity maximum, the particle fluxes accelerated during flares have the most effective effect on the Earth's atmosphere and magnetosphere. At the activity decline phase, by the end of the 11-year activity cycle, with a decrease in the number of flares and the development of an interplanetary current sheet, the stationary streams of the enhanced solar wind become more significant. Rotating together with S., they cause geomagnets repeating every 27 days. indignation. This recurrent (repetitive) activity is especially high for even-numbered cycle ends when the magnetic direction is the fields of the solar "dipole" are antiparallel to the earth's.

Lit.:
Martynov D. Ya., Course of General Astrophysics, 3rd ed., M., 1978;
Menzel D. G., Our Sun, trans. from English, M., 1963; Solar and solar-terrestrial physics. Illustrated dictionary of terms, trans. from English, M., 1980;
Shklovsky I. S., Physics of the solar corona, 2nd ed., M., 1962;
Severny A. B., Magnetic fields of the Sun and stars, "UFN", 1966, v. 88, c. 1, p. 3-50; - Solar corona - granulation

Earthly life owes its origin to the heavenly body. It warms and illuminates everything on the surface of our planet. No wonder the worship of the Sun and its representation as a great heavenly god was reflected in the cults of the primitive peoples who inhabited the Earth.

Centuries, millennia have passed, but its importance in human life has only increased. We are all children of the Sun.

What is the Sun?

A star from the Milky Way Galaxy, with its geometric shape, representing a huge, hot, gaseous ball, constantly radiating energy flows. The only source of light and heat in our star-planetary system. Now the Sun is in the age of a yellow dwarf, according to the generally accepted classification of the types of stars in the universe.

Characteristics of the Sun

The sun has the following properties:

• Age -4.57 billion years;
• Distance to Earth: 149,600,000 km
• Mass: 332,982 Earth masses (1.9891 10³⁰ kg);
• The average density is 1.41 g / cm³ (it increases 100 times from the periphery to the center);
• The orbital speed of the Sun is 217 km/s;
• Rotation speed: 1.997 km/s
• Radius: 695-696 thousand km;
• Temperature: from 5,778 K on the surface to 15,700,000 K in the core;
• Corona temperature: ~1,500,000 K;
• The sun is stable in its brightness, it is located in 15% of the brightest stars in our Galaxy. It emits less ultraviolet rays, but has a greater mass compared to similar stars.

What is the sun made of?

In terms of its chemical composition, our luminary is no different from other stars and contains: 74.5% hydrogen (by mass), 24.6% helium, less than 1% other substances (nitrogen, oxygen, carbon, nickel, iron, silicon, chromium, magnesium and other substances). Inside the nucleus, there are continuous nuclear reactions that turn hydrogen into helium. The vast majority of the mass of the solar system - 99.87% belongs to the sun.

Our Sun is truly a unique star, if only because its glow made it possible to create conditions suitable for life on our planet Earth, which, either by an amazing coincidence of circumstances, or by God's ingenious design, is at an ideal distance from the Sun. Since ancient times, the Sun has been under the close attention of man, and if in ancient times priests, shamans, druids revered our luminary as a deity (in all pagan cults there were solar gods), now the Sun is actively studied by scientists: astronomers, physicists, astrophysicists. What is the structure of the Sun, what are its characteristics, its age and location in our galaxy, read about all this further.

Location of the sun in the galaxy

Despite its huge size relative to our planet (and other planets), on a galactic scale, the Sun is far from the largest star, but very small, there are stars much larger than the Sun. Therefore, astronomers classify our luminary as a yellow dwarf.

As for the location of the Sun in the galaxy (as well as our entire solar system), it is located in the Milky Way galaxy, closer to the edge of the Orion arm. The distance from the center of the galaxy is 7.5-8.5 thousand parsecs. In simple terms, you and I are not exactly at the outskirts of the galaxy, but we are also relatively far from the center - a kind of “sleeping galactic region”, not on the outskirts, but not in the center either.

This is what the location of the Sun looks like on a galactic map.

Characteristics of the Sun

According to the astronomical classification of celestial objects, the Sun belongs to a G-class star, it is brighter than 85% of other stars in the galaxy, many of which are red dwarfs. The diameter of the Sun is 696342 km, the mass is 1.988 x 1030 kg. If we compare the Sun with the Earth, then it is 109 times larger than our planet and 333,000 times more massive.

Comparative sizes of the Sun and planets.

Although the Sun appears yellow to us, its true color is white. The visibility of yellow is created by the atmosphere of the star.

The temperature of the Sun is 5778 degrees Kelvin in the upper layers, but as it approaches the core, it increases even more and the core of the Sun is incredibly hot - 15.7 million degrees Kelvin

The Sun also has strong magnetism, on its surface there are north and south magnetic poles, and magnetic lines that reconfigure with a frequency of 11 years. At the time of such rearrangements, intense solar emissions occur. Also, the magnetic field of the Sun affects the magnetic field of the Earth.

Structure and composition of the Sun

Our Sun is mainly composed of two elements: (74.9%) and helium (23.8%). In addition to them, it is present in small quantities: (1%), carbon (0.3%), neon (0.2%) and iron (0.2%). Inside the Sun is divided into layers:

• core,
• radiation and convection zones,
• photosphere,
• atmosphere.

The core of the Sun has the highest density and occupies approximately 25% of the total solar volume.

The structure of the Sun is schematic.

It is in the solar core that thermal energy is formed through nuclear fusion, which transforms hydrogen into helium. In fact, the core is a kind of solar motor, thanks to it, our luminary emits heat and warms all of us.

Why does the sun shine

Just the same, the glow of the Sun occurs due to the tireless work of the solar core, more precisely, the thermonuclear reaction that constantly takes place in it. The burning of the Sun occurs due to the conversion of hydrogen into helium, this is the eternal thermonuclear reaction that constantly feeds our luminary.

sunspots

Yes, there are spots on the Sun. Sunspots are darker regions on the solar surface, and they are darker because their temperature is lower than the temperature of the surrounding photosphere of the Sun. Sunspots themselves are formed under the influence of magnetic lines and their reconfiguration.

sunny wind

The solar wind is a continuous stream of plasma coming from the solar atmosphere and filling the entire solar system. The solar wind is formed due to the fact that due to the high temperature in the solar corona, the overlying layers cannot balance with the pressure in the corona itself. Therefore, there is a periodic ejection of solar plasma into the surrounding space. There is a whole separate article about the phenomenon on our website.

A solar eclipse is a rare astronomical event in which the Moon is the Sun, in whole or in part.

Schematically, a solar eclipse looks like this.

The evolution of the Sun and its future

Scientists believe that the age of our star is 4.57 billion years. At that distant time, it was formed from a part of a molecular cloud represented by helium and hydrogen.

How was the Sun born? According to one of the hypotheses, the helium-hydrogen molecular cloud started rotating due to the angular momentum and at the same time began to heat up intensely as the internal pressure increased. At the same time, most of the mass was concentrated in the center, and turned into the Sun itself. Strong and pressure led to an increase in heat and nuclear fusion, thanks to which both the Sun and other stars work.

This is how the evolution of a star, including the Sun, looks like. According to this scheme, our Sun is currently in the phase of a small star, and the current solar age is in the middle of this phase. In about 4 billion years, the Sun will turn into a red giant, expand even more and destroy Venus, and possibly our Earth. If the Earth as a planet still survives, then life on it by that time will still be impossible. Since in 2 billion years the glow of the Sun will increase so much that all the earth's oceans will simply boil away, the Earth will be incinerated and turn into a continuous desert, the temperature on the earth's surface will be 70 C, and if life is possible, then only deep underground. Therefore, we still have about a billion-plus years to find a new refuge for humanity in the very distant future.

But back to the Sun, turning into a red giant, it will stay in this state for about 120 million years, then the process of reducing its size and temperature will begin. And when the remaining helium in its core is burned in a constant furnace of thermonuclear reactions, the Sun will lose its stability and explode, turning into a planetary nebula. The earth at this stage, as well as the neighboring one, is very likely to be destroyed by a solar explosion.

After another 500 million years, a white dwarf will form from the solar nebula, which will last for another trillions of years.

• Inside the Sun, you can put a million Earths or planets, the size of ours.
• In shape, the Sun forms an almost perfect sphere.
• 8 minutes and 20 seconds - it is during this time that a sunbeam reaches us from its source, despite the fact that the Earth is 150 million km away from the Sun.
• The word "Sun" itself comes from the Old English word for "south" - "South".
• And we have bad news for you, in the future the Sun will incinerate the Earth, and then completely destroy it. This will happen, however, not earlier than in 2 billion years.

Sun, video

And in conclusion, an interesting scientific documentary from the Discovery Channel - "What the Sun is hiding."

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