Eclipses are among the most spectacular astronomical phenomena. However, no technical means can fully convey the sensations that arise in the observer. And yet, due to the imperfection of the human eye, it cannot see everything at once. The subtle details of this wonderful picture can only be revealed and captured by special photography and signal processing techniques. The variety of eclipses is far from being limited to phenomena in the Sun-Earth-Moon system. Relatively close located cosmic bodies regularly cast shadows on each other (it is only necessary that there be some powerful source of light radiation nearby). By observing this cosmic shadow theater, astronomers gain a lot of interesting information about the structure of the Universe. Photo by Vyacheslav Khondyrev

In the Bulgarian resort of Shabla, August 11, 1999 was an 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 was supposed to cross the Black Sea coast, and the duration of the full phase, according to calculations, reached 3 minutes 20 seconds. The excellent weather was consistent with long-term data, but everyone looked with alarm at the cloud hanging over the mountains.

In fact, the eclipse was already underway, it’s just that few people were interested in its partial phases. The full phase, which still had half an hour left before it started, was a different matter. A brand new digital SLR, specially purchased for this occasion, was in full readiness. Everything is thought out to the smallest detail, every movement is rehearsed dozens of times. The weather had no time to deteriorate, and yet for some reason anxiety grew. Maybe the fact is that the light has noticeably decreased and it has become sharply colder? But this is how it should be as the full phase approaches. However, the birds cannot understand this - all the birds capable of flying took to the air and, screaming, made circles above our heads. The wind blew from the sea. It grew stronger with every minute, and the heavy camera began to tremble on the tripod, which until recently had seemed so reliable.

There was nothing to do - a few minutes before the calculated moment, risking ruining everything, I went down the sandy hill to its foot, where the bushes extinguished the wind. A few movements, and literally at the last moment the technique was set up again. But what is this noise? Dogs bark and howl, sheep bleat. It seems that all animals capable of making sounds do so as if it were the last time! The light is dimming every second. The birds are no longer visible in the darkened sky. Everything calms down at once. The filamentous solar crescent illuminates the seashore no brighter than full moon. Suddenly it goes out too. Anyone who watched him in the last seconds without a dark filter probably saw nothing in the first moments.

My fussy excitement gave way to real shock: the eclipse that I had been dreaming about all my life has already begun, precious seconds are flying by, and I can’t even raise my head and enjoy the rarest spectacle - photography first of all! With each press of the button, the camera automatically takes a series of nine photographs (in bracketing mode). One more. Again and again. 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 pearl crown with a yellowish-cream tint, and bright pink prominences flashed 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 fade and merge with the dark blue background of the sky. The effect of presence is as if I was 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 floating out from behind the Moon. How quickly it was all over! The prominences and rays of the corona are visible for a few more seconds, and the shooting continues until the last. The program is completed! A few minutes later the day breaks out again. The birds immediately forgot their fright from the extraordinary short night. But for many years now my memory has retained a feeling of the absolute beauty and grandeur of the cosmos, a sense of participation in its secrets.

How the speed of light was first measured

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, they could be used to find out Greenwich time far from their native shores, which was necessary to determine the longitude of a ship. 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 nautical almanac and comparing them with local time obtained from elementary astronomical observations, you can determine your longitude. In 1676, Danish astronomer Ole Christensen Römer noticed that the eclipses of Jupiter's moons deviated slightly from the predicted times. The Jovian clock either went ahead by a little over eight minutes, then, after about six months, fell 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 a 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, 16.6 minutes, corresponded to the time it took the light to travel the diameter of the Earth's orbit. This is how Roemer measured the speed of light for the first time.

Meetings at the celestial nodes

By an amazing coincidence, the apparent sizes of the Moon and the Sun are almost the same. Thanks to this, in rare moments 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 did not have 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 Moon intersect at two points - nodes, through which the Sun passes approximately 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 on the surface of the Earth, forms an oval shadow spot, which moves at high speed along the Earth's surface. Only people caught in it will see the lunar disk completely covering the solar one. For an observer of the total phase band, the eclipse will be partial. Moreover, in the distance you may not even notice it - 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 full 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 its maximum distance, the lunar shadow cone falls slightly short of the Earth's surface. In this case, the apparent size of the Moon turns 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, making it difficult to see the corona. Astronomers, of course, are primarily interested in total eclipses, in which the sky darkens so much that the radiant corona can be observed.

Lunar eclipses (from the point of view of a hypothetical observer on the Moon they will, of course, be solar) occur during a full moon, when our natural satellite passes the node opposite to where the Sun is located and falls into the cone of the shadow cast by the Earth. There are no direct sun rays inside the shadow, but the light refracted into earth's atmosphere, still falls on the surface of the Moon. Usually it colors it reddish (and sometimes brownish-greenish) due to the fact that long-wave (red) radiation in the air is absorbed less than short-wave (blue) radiation. One can imagine what horror the suddenly darkened, ominously red disk of the Moon brought to 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 pattern 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 during the era of the Babylonian kings, as well as 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 - from the shape of the shadow creeping onto the Moon, they concluded that the Earth was spherical and that the Sun was much larger than it.

How are the masses of other stars determined?

Alexander Sergeev

Six hundred "sources"

As it moves away from the Sun, the outer corona gradually dims. Where in photographs it merges with the background of the sky, 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 illustrate this article prove the opposite. The problem has a solution! But you need to go to the result not straight ahead, but in a roundabout way: instead of one “ideal” frame, you need to take a series of pictures with different exposures. Different images will reveal regions of the corona located 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 on the Moon, because it moves quickly relative to the Sun). Digital photo processing is not as simple as it seems. However, our experience shows that it is possible to combine any images of one eclipse. Wide-angle with long-focus, with low and long exposure, professional and amateur. These images contain pieces of the work of twenty-five observers who photographed the 2006 eclipse in Turkey, the Caucasus and Astrakhan.

Six hundred original photographs, having undergone many transformations, turned into just a few separate images, but what kind! Now they have all the smallest details of the corona and prominences, the chromosphere of the Sun and stars up to the ninth magnitude. Even at night such stars are visible only 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 tinting 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 the orbits of asteroids are determined

Eclipsing variable stars are called 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 eclipse each other, and the earthly observer sees periodic changes in their total brightness. The most famous eclipsing variable star is Algol (beta Persei). The circulation period in this system is 2 days 20 hours and 49 minutes. During this time, two minima are observed in the light curve. One is deep, when the small but hot white star Algol A disappears completely 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. Careful study of the light curve reveals a lot important information about the stellar system: the size and luminosity of each of the two stars, the degree of elongation of their orbit, the deviation of the stars’ shape from spherical under the influence of tidal forces, and most importantly, the masses of the stars. Without this information it would be difficult to create and verify modern theory 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 in its place, it would obscure approximately 1% of the area of ​​the solar disk and would reduce its brightness by the same amount. This can already be recorded with modern instruments, and today there are already cases of such observations. Moreover, some of them were 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 moon shadow

Extraordinary beauty solar eclipse does not end with a sparkling crown. After all, there is also a glow ring along the entire horizon, which creates a unique illumination at the moment of the full phase, as if the sunset was happening from all directions at once. But few people manage to take their eyes off the crown and look at the amazing colors of the sea and mountains. And here panoramic photography comes to the rescue. Several photographs joined together will show everything that escaped the eye or was not etched into memory.

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

To the right and below the crown is Mercury - it never goes far from the Sun, and not everyone manages to see it. Venus sparkles even lower, and on the other side of the Sun is Mars. All planets are located along one line - the ecliptic - a projection onto the sky of the plane near which all the planets orbit. Only during an eclipse (and also from space) can you see our planetary system surrounding the Sun edge-on 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 under magnification). Hundreds of people who watched the eclipse in March 2006 now feel like they saw it all with their own eyes. But the panoramic photo helped them - it is already posted on the Internet.

How should you take photos?

On March 29, 2006, in the village of Kemer on the Mediterranean coast of Turkey, while waiting for the start of a total eclipse, experienced observers shared secrets with beginners. The most important thing during an eclipse is to remember to open your lenses. This is not a joke, this really happens. And you shouldn’t duplicate each other by taking the same shots. Let everyone shoot what their equipment can do better than others. For observers armed with wide-angle cameras, the outer corona is the main target. We should try to take a series of pictures of her at different shutter speeds. Telephoto lens owners can get detailed images of the middle crown. 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 then the call was 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 of the 2006 eclipse. Everyone now understood that there was still a very, very long way to go from the original photographs to a detailed image of the entire crown. The times when any sharp photograph of an eclipse was considered a masterpiece and the final result of observation are irrevocably gone. Upon returning home, everyone had to work on 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 moving plasma with magnetic fields. First of all, these are sunspots, where part of the thermal energy of the plasma is converted into energy magnetic field and into the kinetic energy of movement of individual plasma flows. Sunspots are colder environment and appear dark against the background of the brighter photosphere, the layer of the sun's atmosphere from which most visible light comes to us. Around the sunspots and throughout the active region, the atmosphere, further heated by the energy of the decaying magnetic fields, becomes brighter, and structures called faculae (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 to the side of them, extended clouds often appear - prominences, clearly visible during the total phase of an eclipse at the edge of the solar disk in the form of bright pink arcs and emissions. The corona is the thinnest and very hot part of the Sun's atmosphere, which seems to evaporate into the surrounding space, forming a continuous stream of plasma moving away from the Sun, called the solar wind. It is this that gives the solar corona the radiant appearance that justifies its name.

Based on the movement of matter in the tails of comets, it was revealed that the speed of the solar wind gradually increases with distance from the Sun. Having moved away from the star by one astronomical unit (the radius of the Earth's orbit), the solar wind “flies” at a speed of 300-400 km/s with a particle concentration of 1-10 protons per cubic centimeter. Encountering obstacles in the form of planetary magnetospheres on its way, the flow of solar wind 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 the 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 emissions 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. Essentially, these are elongated tubes of magnetic fields along which streams of charged particles (mainly energetic protons and electrons) propagate at high speeds. In fact, the visible structure of the solar corona reflects the intensity, composition, structure, direction of movement and other characteristics of the solar wind constantly affecting our Earth. During flares, 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 exclusively close to the Sun. In total, about an hour of observations accumulated. With the invention of the non-eclipse coronagraph (a special telescope in which an artificial eclipse is created), it became possible to constantly monitor the inner regions of the corona from the Earth. It is also always possible to detect radio emission from 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 Earth only during 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 Solar Orbiting Heliospheric Observatory SOHO, launched in late 1995 as a joint effort by the European Space Agency and NASA. In SOHO images, the rays of the corona are very long, and many stars are visible. However, in the middle, in the area of ​​the inner and middle crown, there is no image. The artificial “moon” in the coronagraph is large and obscures much more than the real one. But there is no other way - the Sun is shining too brightly. So satellite imagery does not replace observations from the ground. But space and terrestrial photographs of the solar corona perfectly complement each other.

SOHO also constantly observes the surface of the Sun, and eclipses do not interfere with 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 were 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 in the world is already being called “Russian”, since it will mainly be observed in our country. In the afternoon of August 1, 2008, the full phase strip 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, in Gorno-Altaisk this will be the second eclipse in just 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: this is enough for photographing the corona and ideal for panoramic photography. The weather in Siberia at this time is usually good. It's not too late to prepare a couple of cameras 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 USA in 2017 and 2024. In Russia, the break will last almost half a century - until April 20, 2061.

If you're ready, here you go good advice: observe in groups and exchange the resulting 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 staying at home, will, thanks to you, see the eclipse of the Sun - a crowned star.

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 or by God’s ingenious plan, 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, and druids revered our luminary as a deity (all pagan cults had 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 on about all this.

Location of the Sun in the galaxy

Despite its enormous size relative to our planet (and other planets), on a galactic scale, the Sun is far from the most big star, and even very small, there are stars much larger than the Sun. Therefore, astronomers classify our star 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 galaxy Milky Way, 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, we are not exactly on the outskirts of the galaxy, but we are also relatively far from the center - a kind of “sleeping galactic area”, 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 is a G-class star, brighter than 85% of other stars in the galaxy, many of which are red dwarfs. The diameter of the Sun is 696342 km, mass - 1.988 x 1030 kg. If we compare the Sun with the Earth, 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 real color is white. Visibility yellow created by the atmosphere of the star.

The temperature of the Sun is 5778 degrees Kelvin in 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 are reconfigured every 11 years. At the time of such restructuring, 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, there 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 Sun's core 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 generated through nuclear fusion, transforming hydrogen into helium. In fact, the core is a kind of solar motor, thanks to it, our luminary releases heat and warms us all.

Why does the sun shine

It is precisely the glow of the Sun that occurs due to the tireless work of the solar core, or more precisely, the thermonuclear reaction that constantly occurs 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 too. Sunspots are darker areas 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.

solar 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 because, 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 release 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 phenomenon in which the Moon is the Sun, in whole or in part.

Schematically, a solar eclipse looks like this.

Evolution of the Sun and its future

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

How was the Sun born? According to one hypothesis, the helium-hydrogen molecular cloud began to rotate due to 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 concentrated in the center and turned into the Sun itself. Strong pressure led to an increase in heat and nuclear fusion, thanks to which both the Sun and other stars work.

This is what the evolution of a star, including the Sun, looks like. According to this scheme in at the moment Our Sun is in a small star phase, 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 does survive, then life on it by that time will no longer be possible. 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 complete desert, the temperature on the earth’s surface will be 70 C and if life is possible, it will only be deep underground. Therefore, we still have about a billion or so years to find a new refuge for humanity in the very distant future.

But let's return to the Sun, having turned into a red giant, it will remain in this state for about 120 million years, then the process of decreasing 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, will most likely be destroyed by a solar explosion.

In another 500 million years, a white dwarf will form from the solar nebula, which will exist for trillions more years.

• You could fit a million Earths or planets the size of ours inside the Sun.
• The shape of the Sun forms an almost perfect sphere.
• 8 minutes and 20 seconds - this is the time it takes for a sunbeam to reach 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, no earlier than in 2 billion years.

Sun, video

And finally, an interesting scientific documentary from the Discovery Channel - “What the Sun Hides.”

When writing the article, I tried to make it as interesting, useful and high-quality as possible. I would be grateful for any feedback and constructive criticism in the form of comments on the article. You can also write your wish/question/suggestion to my email. [email protected] or on Facebook, sincerely the author.

Has high temperature. At the surface it is about 5500 degrees Celsius. The Sun has an atmosphere called the corona. This area consists of superheated gas - plasma. Its temperature reaches more than 3 million degrees. And scientists are trying to understand why the outer layer of the Sun is so much hotter than everything that lies underneath.

The problem that confuses scientists is quite simple. Since the source of energy is at the center of the Sun, its body should become progressively cooler as one moves away from the center. But observations suggest the opposite. And so far scientists cannot explain why the Sun's corona is hotter than its other layers.

Old secret

Despite its temperature, the solar corona is usually not visible to an observer on Earth. This is due to the intense brightness of the rest of the Sun. Even sophisticated instruments cannot study it without taking into account the light emanating from the surface of the Sun. But this does not mean that the existence of the solar corona is a recent discovery. It can be observed in rare but predictable events that have fascinated people for thousands of years. These are complete.

In 1869, astronomers took advantage of such an eclipse to study the outer layer of the Sun that suddenly became visible to observation. They pointed spectrometers at the Sun to study the elusive corona material. Researchers discovered an unfamiliar green line in the spectrum of the corona. The unknown substance was named coronium. However, seventy years later, scientists realized that it was a familiar element - iron. But heated to unprecedented millions of degrees.

An early theory said that acoustic waves (think of the Sun's material compressing and expanding like an accordion) could be responsible for the temperature of the corona. In many ways, this is similar to how a wave throws drops of water at high speed onto the shore. But solar probes have been unable to find waves with the power to explain the observed coronal temperature.

For almost 150 years, this mystery has been one of the small but interesting mysteries of science. At the same time, scientists are confident that their knowledge of the temperature both on the surface and in the corona is quite correct.

The Sun's magnetic field: how does it work?

Part of the problem is that we don't understand many of the small events that happen on the Sun. We know how it does its job of warming our planet. But models of the materials and forces involved in this process simply do not exist yet. We cannot yet get close enough to the Sun to study it in detail.

The answer to most questions about the Sun these days is that the Sun is a very complex magnet. The earth also has a magnetic field. But, despite the oceans and underground magma, it is still much denser than the Sun. Which is simply a large clump of gas and plasma. The earth is a harder object.

The sun also rotates. But since it is not solid, its poles and equator rotate with at different speeds. Matter moves up and down the layers of the Sun, like in a pan of boiling water. This effect causes disorder in the magnetic field lines. The charged particles that make up the outer layers of the Sun travel along lines such as high-speed trains. railways. These lines break and reconnect, releasing enormous amounts of energy (solar flares). Or they produce vortices full of charged particles, which can be freely thrown from these rails into space at colossal speed (coronal mass ejection).

We have many satellites that are already tracking the Sun. Solarer Pro, launched this year, is just beginning its observations. It will continue its work until 2025. Scientists hope that the mission will provide answers to many mysterious questions about the Sun.

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We became familiar with the rotation of the Sun and the solar-terrestrial intercentric motion.
Now let's turn our gaze to the Moon!

How does the Moon rotate, how does it move around the planet Earth and in the system of mutual centrism between the Sun and the Earth?
We know from our school astronomy course that the Moon rotates around the Earth in the same direction as the Earth around its axis. The time of a complete revolution (rotation period) of the Moon around the Earth relative to the stars is called sidereal or sidereal month (lat. sidus - star). It amounts to 27,32 days.
Synodic month, or lunation (Greek sinodos - conjunction) is the time interval between two successive identical phases of the Moon or the period of time between successive new moons - averages 29.53 days (709 hours). The synodic month is longer than the sidereal month. The reason for this is the rotation of the Earth (together with the Moon) around the Sun. In 27.32 days, the Moon makes a complete revolution around the Earth, which during this time passes an arc of approximately 27° in its orbit. More than two days are needed for the Moon to again take the appropriate place relative to the Sun and Earth, i.e. so that this phase (new moon) begins again.
Moon path (the trajectory of the Moon on the celestial sphere), like the solar ecliptic, passes through the 12 zodiac constellations. The reason for this is the actual rotation of the Moon around the Earth in a plane almost coinciding with the plane of our planet’s orbit. The angle between the planes of the ecliptic and the monthly lunar path is only 5°9".
The moon rotates on its axis , but it always faces the Earth with the same side, that is, the Moon’s revolution around the Earth and rotation around its own axis are synchronized.

How to practically confirm official statements?

For this purpose, let us turn to such a phenomenon as an eclipse of the Sun, in which it is the Moon that plays a key role.
Solar eclipse - an astronomical phenomenon, which consists in the fact that the Moon covers (eclipses) completely or partially the Sun from an observer on Earth. A solar eclipse is possible only on a new moon, when the side of the Moon facing the Earth is not illuminated and the Moon itself is not visible. Eclipses are only possible if the new moon occurs near one of two lunar nodes (the point of intersection of the apparent orbits of the Moon and the Sun), no more than about 12 degrees from one of them.
The Moon's shadow on the earth's surface does not exceed 270 km in diameter, so a solar eclipse is observed only in a narrow strip along the path of the shadow. Since the Moon revolves in an elliptical orbit, the distance between the Earth and the Moon at the time of an eclipse can be different; accordingly, the diameter of the lunar shadow spot on the Earth’s surface can vary widely from maximum to zero (when the top of the lunar shadow cone does not reach the Earth’s surface). If the observer is in the shadow, he sees a total solar eclipse, in which the Moon completely hides the Sun, the sky darkens, and planets and bright stars may appear on it. Around the solar disk hidden by the Moon you can observe solar corona , which is not visible in the normal bright light of the Sun. Because the temperature of the corona is much higher than that of the photosphere, it has a faded bluish color, unexpected for those who see it for the first time, and very different from the expected color of the Sun. When an eclipse is observed by a stationary ground-based observer, the total phase lasts no more than a few minutes. The minimum speed of movement of the lunar shadow on the earth's surface is just over 1 km/s. During a total solar eclipse, astronauts in orbit can observe the running shadow of the Moon on the Earth's surface.

Let's look at the video of how Wikipedia presents the passage of the Moon through the disk of the sun at a great distance from the Earth.

https://upload.wikimedia.org/wikipedia/commons/transcoded/2/29/Moon_transit_of_sun_large.ogv/Moon_transit_of_sun_large.ogv.480p.vp9.webm
Video 1.

Step by step it looks like this:


Fig 1. The passage of the Moon through the disk of the sun at a great distance from the Earth 02/25/2007 .
The moon passes across the solar disk in the videofrom left to right. Surely this is a telescope shot from a satellite.

How does the Moon's shadow pass across the Earth during an eclipse?

Consider a recent real-life total solar eclipse!
Total solar eclipse on August 21, 2017.
Total solar eclipse on August 21st 2017 - this is the 22nd eclipse one hundred and forty-fifth of Saros.
The area of ​​its best visibility falls in the middle and subtropical latitudes of the northern hemisphere.

Video 2. Animation SZ 08/21/2017
This animation shows that moon shadow moves across the Western Hemisphere of the Earth, North America from left to right or from west to east.

The eclipse reaches its maximum at the point with coordinates 37°N, 87.7°W, lasts a maximum of 2 minutes 40 seconds, and the width of the lunar shadow on the earth's surface is 115 kilometers. At the moment and at the point of greatest eclipse, the direction to the sun (azimuth) is 198°, and the height of the sun above the horizon is 64°.
Dynamic world time at the moment of greatest eclipse: 18:26:40, dynamic time correction: 70 seconds.
The axis of the shadow runs between the center of the Earth and the north pole; the minimum distance from the center of the Earth to the axis of the lunar shadow cone is 2785 kilometers. Thus, the Gamma of the eclipse is 0.4367, and the maximum phase reaches 1.0306.

Total solar eclipse - a solar eclipse in which the cone of the lunar shadow crosses the earth's surface (the Moon is close enough to the Earth to completely cover the Sun). The average length of the lunar shadow is 373,320 km, and the distance from the Earth to the Moon on August 21, 2017 is 362235 km. Moreover, the apparent diameter of the Moon is 1.0306 times greater than the apparent diameter of the solar disk. During a total eclipse, the solar corona, stars and planets located near the Sun are visible.

Figure 2. The passage of the lunar shadow across the western hemisphere of the Earth.

Look at NW in the original, through the eyes of observers in the USA.

https://youtu.be/lzJD7eT2pUE
Video 3.

Fig 3. Phases of a solar eclipse.
(above), gradually covers the Sun, forming its left crescent. Closes completely, then opens the right crescent of the Sun.
We see a picture opposite to that shown in Video and Fig. 1.

2017 total solar eclipse from Idaho Falls, State Idaho, August 21, 2017.

Video 4. NW in Idaho.

Rice. 4,5,6. NW in Idaho.
Interesting burst of sunlight after a total eclipse?

2017 Total Solar Eclipse from Beatrice, Nebraska on August 21, 2017
https://youtu.be/gE3rmKISGu4
Video 5. NW in Nebraska.
Also in these videos, the Moon passes through the Sun from the top right, goes down to the left, revealing the Sun.

Now let's see how telescopes installed on artificial earth satellites record a solar eclipse.
Solar Eclipse 2017 as seen by Hinode JAXA on August 21, 2017.

Video 6.
The Hinode solar observing satellite captured a partial solar eclipse on August 21, 2017. The images were taken by the X-ray telescope (XRT) aboard Hinode as it flew over the Pacific Ocean (off the west coast of the United States). at an altitude of 680 km.

From satellite too The Moon is moving towards the Sun from the right, only from below.

Now let's look at the movement of the moon's shadow across the globe.

2017 total solar eclipse observed by DSCOVR EPIC (4K)

Video 7.

NASA's Earth Polychromatic Imaging Camera (EPIC) aboard NOAA's Deep Space Observatory (DSCOVR) captured the August 21, 2017 Total Solar Eclipse from space.
We see the movement of some shadow across the surface of the western hemisphere. It moves from west to east, ahead of the earth's own rotation in the same direction!
Still, the picture is not perceived by a living planet; as if the “simulator” is reproducing some programmed fragment of movement. The clouds rotate synchronously with the Earth. Several questions arise: Why do clouds remain the same when the earth rotates? How fast and why does the lunar shadow move in a given direction? How long did it take for this shadow to cross America?

Let's look at good animation this solar eclipse.

Video 8. Total solar eclipse 2017.

Rice. 7,8,9. Movement of the lunar shadow across the globe during NW on August 21, 2017.

Ecliptic line - plane of motion, clearly visible in the eclipse of the Moon and the Sun. We are taught that the phenomenon of an eclipse occurs only along the described line.
We also know well that the ecliptic line does not rise above the Tropic of Cancer (23.5° above the celestial equator) and does not fall below the Tropic of Capricorn (-23.5° below the celestial equator).
The sun is at the zenith (the point of the celestial sphere located above the observer's head) only in the region of the globe lying between the tropics of Cancer and Capricorn. The tropics are imaginary parallel circles on the surface of the globe, located 23 degrees and 27 minutes from the equator to the north and south. To the north of the equator is the Northern Tropic (also known as the Tropic of Cancer), to the south is the Southern Tropic (Tropic of Capricorn). In the tropics, once a year (June 22 on the Tropic of Cancer and December 22 on the Tropic of Capricorn), the center of the Sun passes through the zenith at noon. Between the tropics lies a region at each point of which the Sun is at its zenith twice a year. North of the Tropic of Cancer and south of the Tropic of Capricorn, the Sun never rises to its zenith.

When projected onto the globe, the ecliptic passes between 23.5° north latitude and south latitude, between the Tropics of Cancer and Capricorn.

Rice. 10. Globe, the equator and tropics of Cancer and Capricorn are indicated.

The question arises: Why do eclipses occur above the Tropic of Cancer and below the Tropic of Capricorn if the Sun's ecliptic is not projected onto these areas?

Let's look carefully at Fig 6,7,8- SZ animation, on the displacement of the point - the center of the total eclipse of the Sun over North America. This point runs from left to right, west to east, from the 50th to the 30th parallel north. So the projection of a total eclipse is shadow point movement(total phase of the eclipse) passes above the Tropic of Cancer, above 23.5° north latitude.
Consequently, the statement that eclipses occur only along the line of the solar ecliptic is refuted!

According to the animation credits:
To the staff Oregon in the northwest the shadow of the total eclipse was entering 10.15.50 am , 44°53"N, 125°88"W. (Fig. 7)
Out of state South Carolina (Charleston) in the southeast the shadow came into 02.48.50 pm (14.48.50) , 32°49"N, 79°03"W. (Fig. 9)
Between these points of order 4000 km. The shadow point passed in 4 hours 33 minutes ( 16380 sec). So the shadow passed with speed 0.244 km/sec.
According to the data obtained, complete SZ occurred on a trajectory line much higher than the ecliptic, at latitude 32° - 44 ° and above the Tropic of Cancer (23.5°). Moreover, we do not take the movement of penumbra, but only the movement of the point of total eclipse, when the Moon completely covers the Sun. What does it mean? Are the Sun and Moon not currently in the ecliptic when projected at 44 degrees north latitude on Earth? And the declination of the Sun in the sky at this moment is +12° (see below) above the celestial equator and does not go beyond the boundaries of the tropics. And astronomers know that the declination completely corresponds to the Earth’s latitude. Are they lying? So, the celestial equator does not coincide with the earth's? Why does this happen?

Let's compare with the Astrocalculator data.


Screen 1. 08/21/2017 observation point 37°N, 87.7°W

The angle between the planes of the ecliptic and the monthly path of the Moon is small, maximum 5°9".
The ecliptic is indicated by one white line, and the trajectory of the Moon is indicated by multiple lines.
We see that eclipse occurs at the ascending lunar node.

Screen 2,3,4. Phases of a solar eclipse. The Moon “collides” with the Sun from the west (right).

The astro calculator reproduces the sky through the eyes of an observer who faces south. East is on the left, west is on the right. We see that the moon is moving from the right (west), “running over” the sun, we see its left crescent. After a total eclipse we see the right solar crescent. Everything is exactly as in Rice. 3. For the observer, the Moon and the Sun move from left to right, from east to west - sunrise, sunset (visibility due to the earth's rotation).

On the frames (screenshots) of the calculator it is noticeable that the Sun and the Moon are on 10 o'clock meridian(right ascension) in the zodiac constellation Leo, almost next to the star Regulus.

Screen 5. SZ occurs in constellation Leo, next to the star Regul.
Sun declination +11°52".

The earth rotates counterclockwise (from West to East) at a speed 0.465 km/sec.
The moon rotates around the Earth counterclockwise(from West to East)at orbital speed 1,023 km/sec ( divide the orbital length 2x3.14xR (R=384000 km) by the rotation period of 27.32 days).
On Wiki we read: Minimum speed of the lunar shadow on the earth's surface is slightly more than 1 km/s. It turns out that the speed of the Moon in orbit is equal to the speed of movement of the lunar shadow on the Earth. There is also more linear speed of rotation of the earth around its axis.
Is this true? Above we have already calculated the speed of movement of the lunar shadow - 0.244 km/sec. Speed ​​calculated from the official eclipse animation.
Let's continue the research.

Rice. 5. Solar eclipse.

Let's look carefully at this general education picture of the origin of a solar eclipse.

The direction of movement of the Earth is counterclockwise, from west to east indicated red arrow.
If the Moon were static, then the shadow of the Moon during the rotation of the Earth would shift in the opposite direction, to the west, along black arrows.
However, the Moon moves in the direction of the Earth's rotation ( follow the red arrow), its orbital speed is more than twice the speed of its rotation. This is why the lunar shadow moves across the earth's surface from west to east. But at what speed should the shadow move away from the observer on the ground to the left, i.e. towards the east (observer facing south) - is the question open? ... open for discussion!

So, let's summarize some results in our study of the movement of the Moon.

The Moon moves to the left of the stationary stellar sphere (for an observer on earth facing south), from west to east, in the direction of the rotation of the Earth itself, but faster, at a speed of one revolution in 27.3 days, 13.2° per day or 1,023 km/sec. D overtakes the Sun and “runs into” it from the right during a solar eclipse. This happens because the Sun also moves to the east according to the signs of the zodiac, making a full circle in 365.24 days, slower than 1° per day.

The Moon's shadow moves to the left, overtakes the Earth's rotation, and passes along the earth's surface from west to east.

For the observer from Earth (in the northern hemisphere), the picture of the eclipse itself, the shift of the luminaries of the Sun and Moon will occur to the right, to the west, i.e. from sunrise to sunset. This movement is associated with the rotation of the Earth around its axis from west to east.

Some questions raised in the topic remain open, I would be glad to hear answers and justifications.

In the next part I will try to clarify these issues myself, based on the actual rotation of the Moon.
To be continued…