The daily path of the sun. Every day, rising from the horizon in the eastern side of the sky, the sun passes through the sky and is hiding again in the West. For residents of the northern hemisphere, this movement occurs from left to right, for the South - right to left. At noon, the sun reaches the greatest height, or, as Astronomers say, cultures. Noon is the upper climax, and it also happens the bottom - at midnight. In our mid-latitudes, the lower climax of the sun is not visible, as it occurs under the horizon. But for the polar circle, where the sun sometimes does not enter the summer, you can observe the upper and lower climax. On the geographical pole, the daily path of the Sun is almost parallel to the horizon. Appearing on the day of the spring equinox, the sun rises all above and above, while describing circles above the horizon. On the day of summer solstice, it reaches a maximum height (23,5?).

The next quarter of the year, until the autumn equinox, the sun goes down. This is a polar day. Then the polar night comes half a year. In medium latitudes throughout the year, the visible daily path of the Sun is reduced, it increases. The smallest it turns out to be on the day of the winter solstice, the greatest - on the day of the summer solstice. In the days of equinoxy, the Sun is in the heavenly equator. At the same time, it goes back at the point of the East and comes at the West point. In the period from the spring equinox to the summer solstice, the sunrise place is slightly shifted from the point of sunrise to the left, north. And the location is removed from the point of the West to the right, although too north. On the day of the summer solstice, the sun appears in the northeast, and at noon it cultures at the maximum height per year. Sun comes in northwest. Then the places of sunrise and navigate are shifted back to the south. On the day of the winter solstice, the sun rises in the southeast, crosses the heavenly meridian at the minimum height and comes in the south-west. It should be borne in mind that due to refraction (that is, the refraction of light rays in the earth's atmosphere) the visible height of the shine is always more true. Therefore, the sunrise takes place earlier, and the occasion is later than it would be in the absence of an atmosphere. So, the daily path of the sun is a small circle of heaven sphere, parallel to the celestial equator. At the same time, during the year, the Sun moves relative to the heavenly equator to the north, then to the south. The day and night of its way of unequal. They are equal only in the days of equinox, when the sun is in the heavenly equator.

The annual way of the Sun expression "The Way of Sun Among Stars" will seem strange to someone. After all, the day of the stars is not visible. Therefore, it is not easy to see that the sun is slow, about 1? During the day, moving among the stars to the right left. But you can trace how the star sky is changing during the year. All this is a consequence of the appeal of the Earth around the Sun. The path of visible annual movement of the sun on the background of the stars is referred to as Ecliptic (from the Greek "Eclipse" - "Eclipse"), and the period of turnover by ecliptic - the Starry Year. It is equal to 265 days 6 o'clock 9 minutes 10 seconds, or 365, 2564 average sunny day. Ecliptic and heavenly equator intersect at an angle of 23? 26 "at the points of spring and autumnal equinox. In the first of these points, the sun is usually March 21, when it moves from the southern hemisphere of the sky to the North. In the second - September 23, when moving their northern hemisphere. In the South. In the most remote to the north-point Ecliptic, the sun is June 22 (summer solstice), and to the south - December 22 (winter solstice). In the leap year, these dates are shifted for one day. Of the four points of ecliptic, the main point is the point of spring equinox. It is from her that one of the celestial coordinates is counted - direct climb. It also serves to refer to the stellar time and tropical year - the time interval between the two consecutive passing of the center of the Sun through the spring equinox. The tropical year determines the change of the seasons of the year on our planet. Since the spring of the spring Equinoxies slowly moves among the stars due to the precession of the earth's axis, the duration of the tropical About the year less than the duration of the star. It is 365,2422 medium sunny day. About 2 thousand years ago, when Hipparh made his star catalog (the first ending with the whole), the point of spring equinox was in the constellation of Aries. To our time, she moved almost 30?, In the constellation of fish, and the point of autumn equinox - from the constellation of scales in the constellation of the Virgin.

But according to the tradition of the point of equinoxies, they are designated by the previous signs of the former "equinocal" constellations - Aries and scales. The same happened with the points of solstice: the summer in the constellation the Taurus is celebrated by the sign of cancer, and the winter in the constellation Sagittarius is a sign of Capricorn. Finally, the last, which is associated with the visible annual movement of the sun. Half of the ecliptic from the spring equinox to the autumn (from March 21 to September 23) the sun passes for 186 days. The second half, from the autumn equinox and the Spring, - for 179 days (180 in the leap year). But after all, the half of the ecliptic are equal: each 180?. Consequently, the sun moves by ecliptic unevenly. This unevenness is explained by changing the speed of the Earth's movement along the elliptical orbit around the Sun. The unevenness of the Sun movement by ecliptic leads to different times of the time of the year. For residents of the northern hemisphere, for example, spring and summer for six days longer than autumn and winter. The Earth on June 2-4 is located 5 million kilometers longer than January 2-3, and moves in its orbit slower in accordance with the second law of Kepler. In summer, the Earth receives less heat from the Sun, but the summer in the northern hemisphere is longer than winter. Therefore, in the northern hemisphere of the earth, warmer than in South.

§ 52. The visible annual movement of the Sun and its explanation

Watching the daily movement of the Sun during the year, it can be easily noted in its movement a number of features different from the daily movement of stars. The most characteristic of them are as follows.

1. The place of sunrise and sunset, and therefore, and its azimuth is changed from day to day. Starting from March 21 (when the sun rises at the point of the East, and comes at the West point) On September 23, the sunrise is observed in a nord-e-quarters, and an approach is in Nord-Vestova. At the beginning of this time, the points of sunrise and sunset are moved to the north, and then in the opposite direction. September 23, just like on March 21, the sun rises at the point of the East and comes at the West point. Starting from September 23 to March 21, this phenomenon will repeat in the Sünd-Este and Southwest quarters. Moving the points of sunrise and sunset has a one-year period.

Stars are always upgrading and entering the same horizon points.

2. The meridional height of the sun varies with each day. For example, in Odessa (cf \u003d 46 °, 5 n) on June 22, it will be the highest and equal to 67 °, then it will begin to decrease and will reach the smallest value of 20 °. After December 22, the meridional height of the Sun will begin to increase. This phenomenon is also a one-year period. The meridional height of the stars is always constant. 3. The duration of the time between the climax of some stars and the sun is continuously changing, while the duration of the time between the two climax of the same stars remains constant. So, at midnight we see the cultures of the constellations that are currently on the opposite side of the sphere from the Sun. Then some constellations are inferior to the other, and during the year at midnight alternately, all constellations are prohibited.

4. Duration of the day (or night) is inconvenient during the year. This is especially noticeable if you compare the duration of summer and winter days in big latitudes, for example, in Leningrad, this is because the time of staying over the horizon is different during the year. Stars above the horizon are always the same amount of time.

Thus, the sun, in addition to the daily movement, performed jointly with the stars, has another visible movement on the sphere with the annual period. This move is called visible annual sun movement in heavenly sphere.

The most visual idea of \u200b\u200bthis movement of the Sun is obtained if we daily define its equatorial coordinates - direct ascent a and the declination of it, then at the found values \u200b\u200bof the coordinates we will apply points to the auxiliary celestial sphere and connect their smooth curve. As a result, we get a large circle on the sphere, which will indicate the path of the visible annual movement of the sun. The circle on the celestial sphere, according to which the sun moves, is called Eclipti Ko. The plane of the ecliptic is tilted to the equator plane at a permanent angle G \u003d 23 ° 27, which is called an angle of inclination ecliptic to Equator (Fig. 82).

Fig. 82.

The visible annual movement of the sun on ecliptic occurs in the direction opposite to the rotation of the heavenly sphere, i.e. from the west to the east. Ecliptic intersects with heavenly equator at two points, which are called the points of equinox. The point in which the sun moves from the southern hemisphere to the North, and therefore changes the name of declining from the southern to the north (i.e. with BS on the BN), called a point spring equinox And indicated by the Ya icon. This badge denotes the constellation of Aries, in which this point was once located. Therefore, sometimes it is called the point of the Aries. Currently, the point T is in the constellation of fish.

The opposite point in which the sun passes from the northern hemisphere to the southern and changes the name of his declination with b n on b s, called point of autumn equinox. It is denoted by the icon of the constellation of scales O, in which she once was. Currently, the point of autumn equinox is in the constellation of the Virgin.

Point l called summer point A point L "- point winter solstice.

Let's follow the visible movement of the Sun on Ecliptic during the year.

At the point of spring equinox, the sun comes March 21. Direct climb a and the decline of the Sun B are equal to zero. On the whole globe, the Sun goes back at the point O ST and enters the point W, and the day is equal to the night. From March 21, the sun moves along the ecliptic in the direction of the point of summer solstice. Direct climbing and the decline of the sun is continuously increasing. In the northern hemisphere, astronomical spring comes, and in South - autumn.

June 22, about 3 months, the sun comes to the point of summer solstice L. Direct climb of the sun A \u003d 90 °, and the declination of B \u003d 23 ° 27 "n. Astronomical summer comes in the northern hemisphere (the longest days and short nights), and In South-Winter (the longest nights and short days). With a further movement of the Sun, its northern declination begins to decrease, and the direct climb is still increasing.

Approximately three months later, September 23, the sun comes to the point of autumnal equinox Q. Direct climb of the sun A \u003d 180 °, the alastion B \u003d 0 °. Since B \u003d 0 ° (as well as March 21), for all points of the earth's surface, the Sun goes back at the point O ST and enters the point W. The day will be equal to the night. The name of the decline of the Sun is changing from the North 8n to the South - BS. Astronomical autumn comes in the northern hemisphere, and in South-Spring. With the further movement of the Sun on the ecliptic to the Winter Solstice point U declination 6 and the direct climb of AO increases.

On December 22, the Sun comes to the Winter Solstice point L ". Direct climb a \u003d 270 ° and decline B \u003d 23 ° 27" s. Astronomical winter comes in the northern hemisphere, and in South - summer.

After December 22, the sun moves to the point T. The name of its declination remains southern, but decreases, and the direct climb increases. After about 3 months, March 21, the sun, making a complete turn on the ecliptic, returns to the dot point.

Changes to direct ascent and decline in the sun during the year do not remain constant. For approximate calculations, the daily change in the direct climbing of the Sun is taken equal to 1 °. The change in decoration per day is taken equal to 0 °, 4 for one month to the equinox and one month after, and the change of 0 °, 1 for one month to the solstice and one month after the solcesta; The rest of the time the change in the decline of the Sun is taken equal to 0 °, 3.

The peculiarity of the change in the direct climbing of the Sun plays an important role when choosing basic units to measure time.

The point of spring equinox moves along the ecliptic to towards the annual movement of the sun. Annual movement of it is 50 ", 27 or rounded 50", 3 (for 1950). Consequently, the sun does not reach the original place relative to fixed stars by 50 ", 3. To pass the Sun of the specified path, you will need 20 m M 24 C. For this reason, spring

It comes earlier than the sun graduates and its visible annual movement is 360 ° relative to fixed stars. The displacement of the moment of spring onset was discovered by Hpápuch in II century. BC e. According to the observations of the stars he produced on the island of Rhodes. This phenomenon he called the presence of equinoxies, or precession.

The phenomenon of moving the point of spring equinox caused the need to introduce the concepts of tropical and starry years. The tropical year is called a period of time during which the sun makes a complete turn on the heavenly sphere relative to the point of spring equinox T. "The duration of the tropical year is equal to 365,2422 days. The tropical year is consistent with natural phenomena and accurately contains a full cycle of the season: Spring, Summer, autumn and winter.

Starry year call a period of time during which the sun makes a complete turn around the heavenly sphere relative to the stars. The duration of the starry year is equal to 365,2561 days. Starry year longer tropical.

In his visible annual movement on the heavenly sphere, the Sun passes among various stars located along the ecliptic. Even in ancient times, these stars were divided into 12 constellations, most of which were given animal names. The sky strip along the ecliptic, formed by these constellations, was called the zodiac (animal circle), and the constellations are zodiacal.

By season, the Sun passes the following constellations:

From the joint movement of the sun-annual on ecliptic and daily due to the rotation of the heavenly sphere, the overall movement of the sun on a spiral line is created. The extreme parallels of this line are removed along both sides of the equator at distances B \u003d 23 °, 5.

June 22, when the Sun describes the extreme daily parallel on the northern heavenly hemisphere, it is in the constellation of twins. In the distant past, the sun was in the constellation of cancer. On December 22, the Sun is located in the constellation Sagittarius, and in the past it was in the constellation of Capricorn. Therefore, the extreme northern celestial parallel was called the tropical of cancer, and the South-Tropic of Capricorn. The corresponding earth parallels with the latitudes Cp \u003d bemach \u003d 23 ° 27 "in the northern hemisphere called the tropic of cancer, or the northern tropical, and in the southern - tropic of Capricorn, or the southern tropical.

In the joint movement of the Sun, which occurs according to the ecliptic with the simultaneous rotation of the heavenly sphere, there are a number of features: the length of daily parallels above the horizon and under the horizon (and, consequently, the duration of the day and night), the meridional heights of the sun, the points of the sunrise and enter are changed. . D. All these phenomena depend on the relationship between the geographic latitude of the place and the decline of the Sun. Therefore, for an observer located in different latitudes, they will be different.

Consider these phenomena in some latitudes:

1. The observer is at the equator, cf \u003d 0 °. The axis of the world lies in the plane of the true horizon. Heavenly equator coincides with the first vertical. Daily sunted parallels are parallel to the first vertical, so the sun in his daily movement never crosses the first vertical. The sun rises daily and comes. The day is always equal to the night. In Zenith, the sun occurs twice a year - March 21 and September 23.

Fig. 83.

2. The observer is in the latitude φ
3. The observer is in the latitude of 23 ° 27 "
4. The observer is in the latitude of φ\u003e 66 ° 33 "n or s (Fig. 83). The belt polar. Parallel F \u003d 66 ° 33" N or S is called polar circles. In the polar belt, polar days and nights may occur, that is, when the sun is over the day over the horizon or more than the day under the horizon. The duration of polar days and nights is the greater, the more latitude. The sun rises and comes only in those days when his declination is less than 90 ° -.

5. The observer is on the pole φ \u003d 90 ° N or S. The axis of the world coincides with the sheer line and, therefore, the equator-with the plane of the true horizon. The position of the Meridian observer will be uncertain, so there are no parts of the world. During the day the sun moves parallel to the horizon.

In the days of equinox, polar sunrises or sunset occur. On the days of solstice, the height of the sun reaches the greatest values. The height of the sun is always equal to his declination. Polar day and polar night continue for 6 months.

Thus, due to the various astronomical phenomena, due to the joint daily and annual movement of the Sun in different latitudes (passing through the zenith, phenomena of the polar day and night) and caused by these phenomena of climatic features, the earth's surface is divided into tropical, moderate and polar belts.

Tropical belt It is called a part of the earth's surface (between the latitudes φ \u003d 23 ° 27 "N and 23 ° 27" S), in which the sun rises daily and comes and goes and for a year it happens in the zenith. The tropical belt occupies 40% of the entire earth's surface.

Moderate belt A part of the earth's surface is called, in which the Sun dates back and comes, but never happens in Zenith. There are two moderate belts. In the northern hemisphere between the latoms φ \u003d 23 ° 27 "N and φ \u003d 66 ° 33" n, and in the southern - between the latitudes φ \u003d 23 ° 27 "S and φ \u003d 66 ° 33" s. Moderate belts occupy 50% of the earth's surface.

Polar belt It is called a part of the earth's surface in which polar days and nights are observed. There are two polar belts. The north polar belt propagates from the latitude of φ \u003d 66 ° 33 "n to the north pole, and the southern - from φ \u003d 66 ° 33" s to the southern pole. They occupy 10% of the earth's surface.

For the first time, the proper explanation of the visible annual movement of the Sun in the heavenly sphere was given by Nikolai Copernicus (1473-1543). He showed that the annual movement of the sun on the heavenly sphere is not real movement, but only the visible, reflecting the annual movement of the earth around the sun. The Copernicus World System was named Heliocentric. On this system in the center of the Solar System is the sun, around which planets move, including our land.

Earth simultaneously participates in two movements: rotates around its axis and moves along the ellipse around the sun. The rotation of the Earth around the axis causes a change of day and night. Her movement around the Sun causes a change of seasons. From the joint rotation of the Earth around its axis and movement around the Sun, the visible movement of the sun on the celestial sphere occurs.

To explain the visible annual movement of the Sun on the heavenly sphere, we use Fig. 84. In the center there is Sun S, around which the earth is moving counterclockwise. The earth's axis retains a constant position in space and is an angle equal to 66 ° 33 with an ecliptic plane. Therefore, the plane of the equator is tilted to the plane of the ecliptic at an angle e \u003d 23 ° 27. Next is the heavenly sphere with ecliptic and applied on it signs of the zodiac constellations in the modern location.

To position I, the land comes on March 21. If you look from the ground, the sun is designed to the heavenly sphere at the point that currently in the constellation of fish. The decline of the sun be \u003d 0 °. The observer located at the Earth's Equator sees the sun at noon in Zenith. All earthly parallels are highlighted by half, therefore, in all points of the earth's surface, the day is equal to the night. In the northern hemisphere, astronomical spring begins, and in South - autumn.

Fig. 84.

To position II, the land comes on June 22. Sunfall B \u003d 23 °, 5n. If you look from the ground, the sun is designed in the constellation of twins. For an observer located in the latitude φ \u003d 23 °, 5n, (the sun at noon passes through the zenith. Most of the daily parallels are illuminated in the northern hemisphere and the smaller - in the southern one. The northern polar belt is illuminated and the southern day is illuminated. On the north the polar day And on the south-polar night. In the northern hemisphere of Earth, the rays of the sun fall almost stuck, and in the southern - at an angle, so astronomical summer comes in the northern hemisphere, and in South - Winter.

To position III, the land comes on September 23. The decline of the Sun Bo \u003d 0 ° and it is designed to the point of weight, which is now in the constellation of the Virgin. The observer located on the equator sees the sun at noon in Zenith. All earthly parallels are illuminated by the sun halfway, so at all points of the earth the day is equal to the night. Astronomical autumn begins in the northern hemisphere, and in South - Spring.

On December 22, the Earth comes to position IV Sun is designed in the constellation of Sagittarius. Sunfall 6 \u003d 23 °, 5s. In the southern hemisphere, most of the daily parallels are illuminated than in the northern, so in the southern hemisphere the day is longer than the night, and in North - on the contrary. The rays of the sun in the southern hemisphere fall almost strangling, and north - at an angle. Therefore, an astronomical summer comes in the southern hemisphere, and in Northern - Winter. The sun illuminates the southern polar belt and does not illuminate the North. There is a polar day on the southern polar belt, and in the North - night.

The corresponding explanations can be given for the rest of the intermediate provisions of the Earth.

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Year of the Sun.

The expression "The Way of Sun Among Stars" will seem strange to someone. After all, the day of the stars is not visible. Therefore, it is not easy to note that the sun is slowly, about 1 in a day, moves among the stars to the right left. But you can trace how the star sky is changing during the year. All this is a consequence of the appeal of the Earth around the Sun.

The path of visible annual movement of the sun on the background of the stars is referred to as Ecliptic (from the Greek "Eclipse" - "Eclipse"), and the period of turnover by ecliptic - the Starry Year. It is equal to 265 days 6 o'clock 9 minutes 10 seconds, or 365, 2564 average sunny day.

Ecliptic and heavenly equator intersect at the angle of 23˚26 "at the points of spring and autumn equinox. In the first of these points, the Sun usually happens on March 21, when it moves from the southern hemisphere of the sky to the North. In the second - September 23, when moving their northern hemisphere In the south. In the most remote to the north-point Ecliptic, the sun is June 22 (summer solstice), and to the south - December 22 (winter solstice). In a leap year, these dates are shifted for one day.

Of the four points of the ecliptic, the main point is the point of spring equinox. It is from her that one of the heavenly coordinates is counted - direct climbing. It also serves to refer to the star time and tropical year - the time interval between the two consecutive passages of the center of the Sun through the spring equinox. The tropical year determines the change of seasons on our planet.

Since the spring equinox point slowly moves among the stars as a result of the precession of the earth's axis, the duration of the tropical year is less than the length of the star. It is 365,2422 medium sunny day.

About 2 thousand years ago, when Hipparh made his star catalog (the first ending with the whole), the point of spring equinox was in the constellation of Aries. To our time, she moved almost 30˚, in the constellation of fish, and the point of autumn equinox - from the constellation of scales in the constellation of the Virgin. But according to the tradition of the point of equinoxies, they are designated by the previous signs of the former "equinocal" constellations - Aries and scales. The same happened with the points of solstice: the summer in the constellation the Taurus is celebrated by the sign of cancer, and the winter in the constellation Sagittarius is a sign of Capricorn.

Finally, the last, which is associated with the visible annual movement of the sun. Half of the ecliptic from the spring equinox to the autumn (from March 21 to September 23) the sun passes for 186 days. The second half, from the autumn equinox and the Spring, - for 179 days (180 in the leap year). But after all, the half of the ecliptic is equal: each 180˚. Consequently, the sun moves by ecliptic unevenly. This unevenness is explained by changing the speed of the Earth's movement along the elliptical orbit around the Sun.

The unevenness of the Sun movement by ecliptic leads to different times of the time of the year. For residents of the northern hemisphere, for example, spring and summer for six days longer than autumn and winter. The Earth on June 2-4 is located 5 million kilometers longer than January 2-3, and moves in its orbit slower in accordance with the second law of Kepler. In summer, the Earth receives less heat from the Sun, but the summer in the northern hemisphere is longer than winter. Therefore, in the northern hemisphere of the earth, warmer than in South.

Solar eclipses

At the time of the lunar noving, a solar eclipse can occur - after all, it is in the new moon that the moon passes between the sun and the earth. Astronomers know in advance when and where the solar eclipse will be observed, and report it in astronomical calendars.

Earth got a single satellite, but what! The moon is 400 times less than the sun and just 400 times closer to the ground, so the sun and the moon in the sky seem to be the same sizes. So, with the full sunny eclipse, the moon flaps the bright surface of the Sun, leaving an open all the sunny atmosphere.

EXACTLY at the appointed hour and a minute through the dark glass can be seen how something black crashes on a bright Disk of the Sun, as a black hole appears on it. It gradually grows up until finally the solar circle takes the kind of narrow sickle. At the same time quickly weakens daylight. Here the sun is completely hiding behind a dark damper, the last day ray goes out, and darkness, apparent the extent that it is supreme, spreads around, shifting the person and the whole nature in a silent surprise.

About the eclipse of the Sun on July 8, 1842 in the city of Pavia (Italy) tells English by astronomer Francis Bailey: "When the complete eclipse and sunlight came instantly, there was some bright radiance, like a crown of Il on the naoler around the head. Saint. In any reports about past eclipses were not written about something similar, and I didn't expect to see the magnificence, who was now in front of my eyes. The width of the crown, counting from the circle of the moon disk, was equal to about half the moon diameter. She It seemed composed of the bright rays. Her light was denser near the very edge of the moon, and as the rays removed the crown became weaker, thinner. Weakening of the light went completely smoothly along with an increase in distance. The crown appeared in the form of beams of straight weak rays; their external ends dispelled Fan; Rays were unequal length. The crown was not reddish, not pearl, it was completely white. Her rays were overclocked or flicker, like g Azov flame. As it was not brilliantly this phenomenon, whatever enthusias, but still in this strange, the wonderful spectacle was exactly something ominous, and I fully understand how many people could be shocked and frightened during the times when these phenomena There was quite unexpected.

The most amazing details of the whole picture was the emergence of three large protrusions (Protuberans), which rinsed above the edge of the moon, but were obviously part of the crown. They resembled the mountains of a huge height, on the snow vertices of the Alps, when those are lit by the red rays of the setting sun. Their red flowed into a purple or purple; Perhaps it would be best to go here the shade of peach colors. The light of the protrusions, as opposed to the rest of the crown, was completely calm, the "mountains" did not sparkle and did not shimmer. All three protrusions, a slightly different largest, were visible until the last moment of the total phase of the eclipse. But as soon as the first ray of the sun was broken, the protuberances together with the crown were disappeared without a trace, and bright light of the day was recovered. "This phenomenon, so thin and colorfully described Bailey, lasted a little more than two minutes.

Remember Turgenev boys on the Bezhiang meadow? Pavlusha talked about how the sun did not see, about a man with a janger on the head, which was accepted for Antichrist Crick. So it was a story about the same eclipse on July 8, 1842!

But there was no eclipse on Russia more than the word about the word about Igor's regiment and the ancient chronicle. In the spring of 1185, Novgorod-Seversky Prince Igor Svyatoslavich with brother in Vsevolod, performed by the fortune, went to the Polovtsy to join the glory, and the squad of mining. May 1, in the late afternoon, as soon as the shelves "Lady's grandchildren" (descendants of the Sun) on someone else's land, darled before the laid, the birds of Smallkley, the horses rzhali walked, the shadows of riders were unclear and strange, the steppe drove the cold. Igor looked around and saw that she had the "sun, standing by the month." And Igor Boyars said his and his squad: "Do you see? What does the shine meaning ??". They looked, and saw, and donounced the heads. And they said her husbands: "Our Prince! Does not succeed to us good shine!" Igor answered: "Brothers and squad! The mystery of God's nobody is nobody. And what God is given to us - for the benefit of us or on Mount, - we will see." On the tenth day of May, the squad of Igor flew in a Polovtsy steppe, and the wounded prince was captured.

Sun movement among stars

(lesson - lecture)

This lesson for studentsXI classes engaged in the textbookG.Ya. Myakisheva, B.B. Bukhovtsev "Physics. Grade 11 »(Profile Classes)

Educational purpose of the lesson: Examine the movement of the sun regarding distant stars.

Educational tasks of the lesson:

Determine the main types of the heavenly movement of the Sun and relate them to such phenomena as a change in the duration of the day and night, the change of seasons of the year, the presence of climatic belts;

To form students' skills to find and determine the main planes, lines, the points of the heavenly sphere associated with the movement of the Sun;

To form students' skills to determine the horizontal coordinates of the Sun;

General remarks

Information in the lecture is supplied in a compressed form, so a short phrase may require long reflection. The development of the need to think, and, consequently, in understanding the content of a particular topic of students, correlates with the fulfillment of tasks:

Practical Tips when working with information:

having received new information, think over it and clearly specify the answer to the question: "What is she and for what they informed you?";

get the habit to ask the question "Why?" and independently find a response on his way, thinking, chatting with comrades, a teacher;

checking the formula, solving the problem, etc., perform mathematical operations gradually, recording all intermediate calculations;

Basic questions lecture

The movement of heavenly shine.

Sun movement among stars.

Ecliptic. Ecliptic coordinate system.

Ecliptic - A large range of heavenly sphere, according to which the visible annual movement of the sun occurs. The direction of this movement (about 1 per day) is opposite to the direction of the daily rotation of the Earth. The word "Ecliptic" comes from the Greek word "Eclipse" - eclipse.

The axis of the earth's rotation has a permanent angle of inclination to the plane of the decoration of the Earth around the Sun, equal to about 66 ° 34 "(see Fig. 1). As a result of this angle ε Between the plane of the ecliptic and the plane of the celestial equator is 23 ° 26.

Figure 1. Ecliptic and Heavenly Equator

Relying on Figure 1, fill in the skips in the above definitions.

Ecliptic axis (PP") - ………………

………………………………………….. .

North Pole Ecliptic (P) - .................................................... .

South Pole Ecliptic (P") - ………………………………………………………………………….. .

Ecliptic passes through 13 constellations. Sternoshats does not apply to the zodiacal constellations.

Points of spring (γ) and autumn (ω) equinox Call the points of intersection of ecliptic and heavenly equator. The Point of Spring Equinox is in the constellation of fish (until recently - in the constellation Aries). Date of Spring Equinox - 20 (21) Martha. The point of autumn equinox is in the constellation of the Virgin (until recently - in the constellation of weights). Date of autumn equinox - 22 (23) of September.

Point of summer solstice and the dot of the winter solstice -points that are 90 ° from the equinoxpies. The summer solstice lies in the northern hemisphere, falls on June 22. The winter solstice point lies in the southern hemisphere and falls on December 22.

Ecliptic coordinate system.

Figure 2. Ecliptic coordinate system

As the main plane of the ecliptic coordinate system (Fig. 2), the plane of the ecliptic is chosen. Ecliptic coordinates include:

The latitude and longitude of the stars do not change as a result of the daily movement of the heavenly sphere. The ecliptic coordinate system is used mainly when studying the movement of the planets. This is convenient because the planets move relative to the stars in approximately the plane of the ecliptic. As a consequence β Formulas containing COS β and SIN β can be simplified.

The ratio between degrees, clock and minutes as follows: 360 =24, 15=1, 1=4.

The movement of heavenly lights

Daily movement shone. Daily The paths of shone on the celestial sphere - the circumference, the planes of which are parallel to the celestial equator. These circles are called celestial parallels. The daily movement of the luminaire is a consequence of the rotation of the Earth around its axis. Visibility shums depends on their celestial coordinates, the position of the observer on the surface of the Earth (see Fig. 3).

Figure 3. Daily pathways shone relative to the horizon, for an observer located: A - in medium geographical latitudes; b - at the equator; B - on the Pole of the Earth.

1. Word the theorem about the height of the world pole.

2. Describe how you can explain the properties of the daily movement shone, due to the appeal of the Earth around its axis on different latitudes?

How it changes at the daily movement shone it: a) height; b) direct climb; c) decline?

Is the height, direct climb and the declination of the main points of the celestial sphere: z, z ׳ , P, P. ׳ , N, S, E, W?

3. The movement of the sun among the stars.

Culmination - The intersection phenomenon with the luminaire of the Heavenly Meridian. In the upper climax, the luminaire has the greatest height. Azimuth shining in the upper climax is equal ....... And in the bottom - the smallest. Azimuth shining in the lower climax is equal ... ... the moment of the upper climax of the center of the Sun is called true noona Nizhnya - true fulfillment.

IN husband Luminous ( h. ) or anti-aircraft distance ( z. ) at the time of climps depends on the declination of the shone ( δ) and latitude of observation location ( φ )

Figure 4. Projection of the celestial sphere on the plane of heavenly meridian

Table 3 shows the formulas to determine the height of the shone in the upper and lower climax. The type of expression for the height of the luminaries in the climax is determined with the support in Figure 4.

Table 3.

The height of the shone in the climax

Declination of Svetila

The height of the shone in the upper climax

Height of shone in lower climax

δ < φ

h \u003d 90˚-φ + Δ

h \u003d 90˚-φ-δ

δ = φ

h \u003d 90 ˚

h \u003d 0˚

δ > φ

h \u003d 90˚ + φ-Δ

h \u003d φ + δ-90˚

There are three categories of shone, for places on Earth, for which 0<φ <90˚:

If the declination of the shone Δ< -(90˚- φ ), то оно будет невосходящим. Если склонение светила δ >(90˚- φ), it will be appropriate.

The conditions of the visibility of the Sun and the change of seasons depends on the position of the observer on the surface of the Earth and on the position of the Earth in orbit.

One-year movement of the sun - The phenomenon of the movement of the sun relative to the stars to the side, the inverse daily rotation of the heavenly sphere. This phenomenon is a consequence of the earth's movement around the Sun along the elliptical orbit in the direction of rotation of the Earth around its axis, i.e. counterclockwise, if you look at the North Pole on the South (see Fig. 5).

Figure 5. Tilt the axis of the rotation of the Earth and the seasons

Figure 6. Scheme of land positions at summer and winter solstice

In the one-year movement of the Sun, the following phenomena occur: a change in the midtitus, the position of the points of the sunrise and sunset, the duration of the day and night, the type of starry sky is the same hour after sunset.

The appeal of the Earth around the Sun, as well as the fact that the axis of the daily rotation of the Earth is always parallel to itself anywhere in the earth orbit - the main reasons for changing the seasons of the year. These factors determine a different inclination of the sun's rays with respect to the surface of the Earth and the different degree of illumination of the hemisphere on which it shines (see Fig. 5, 6). The higher the sun over the horizon, the stronger its ability to heat the ground surface. In turn, the change in distance from the Earth to the Sun during the year does not affect the change of seasons: the land, running its elliptical orbit, is located in the closest point in January, and in the most remote - in July.

Using the lecture material, fill in Table 4.

Table 4.

Daily movement of the Sun at different times of the year on medium latitudes

Position on ecliptic

Declining

Halfood height

Minimum height

Point of sunrise

Open point

Duration of the day

20(21) .03

22.06

22(23).09

22.12

Astronomical signs of thermal belts:

1. How will the boundaries of thermal belts change if the angle of inclination of the earth's rotation axis to the plane of the earth orbit will decrease? will be equal to 90.˚?

   With what angle of inclination of the land rotation axis to the plane of its orbit will not be moderate belts?

Change the type of star sky.Each subsequent night compared to the previous star appears a little shifted to the West. From the evening in the evening, the same star rises for 4 minutes earlier. After a year, the type of starry sky is repeated.

If a certain star is located at the point of Zenith at 9 o'clock in the evening on September 1, at what time will it be in Zenith on March 1? Can you see it? Justify the answer.

Precession -the cone-shaped rotation of the earth's axis with a period of 26,000 years under the action of the forces from the Sun and the Moon. The precession movement of the earth causes the North and South Poles of the world to describe in the sky of the circumference: the axis of the world describes around the axis of the ecliptic cone, the radius of about 23˚26 ", remaining, all the time inclined to the plane of the earth's movement at an angle of about 66˚34" clockwise for an observer Northern Hemisphere (Fig. 7).

Precession changes the position of heavenly poles. 2,700 years ago, the star of the Dragon was located near the North Pole of the world, called the Chinese Astronomers of the royal star. Currently, the polar star is α small bear. By 10,000, the North Pole of the world will get closer to the denbent star (α swan). In 13600, the polar star will be vega (α lira).

Figure 7. Precessing earth axis movement

As a result of the precession of the point of spring and autumn equinoxies, summer and winter solstices, slowly move along zodiacal constellations. 5000 years ago, the point of spring equinox was in the constellation of the Taurus, then moved to the constellation of Aries, and now is in the constellation of fish (see Fig. 8). This displacement is
\u003d 50 ", 2 per year.

Figure 8. Precession and nation in the celestial sphere

The attraction of the planets is too little to cause changes in the axis of the axis of the earth rotation, but it acts on the movement of the earth around the Sun, changing the position in the space of the plane of the earth orbit, i.e. Ecliptic planes: The ignition of the ecliptic to the equator is periodically changing, which is currently decreasing by 0 ", 47 per year. Changing the position of the ecliptic plane makes a change, first, in the value of the speed of movement of the equinox points as a result of a precession movement (V \u003d 50", 2 * COS ε), secondly, the curves described by the poles of the world are not closed (Fig. 9).

Figure 9. Precession Movement of the North Pole of the World. Points in the center showing the position of the World Pole

Nature of the earth's axis -small various oscillations of the axis of the earth rotation near their middle position. The nutational oscillations arise because the precession forces of the Sun and the Moon continuously change their magnitude and direction; They are equal to zero, when the sun and the moon are in the plane of the Earth's equator and reach the maximum with the highest removal from it these shums.

As a result of precession and nation of the earth's axis, the Poles of the world actually describe complex wavy lines in the sky (see Fig. 8).

It should be noted that the effects of precession and the nation are generated by external forces that change the orientation of the axis of the rotation of the Earth in space. The body of the Land remains in this case, so to speak, fixed in relation to the changing axis. Therefore, the flag set today to the North Pole will also mark the North Pole in 13,000, and the latitude of the point will remain 90 °. Since neither a precession nor states lead to any changes in latitude on Earth, these phenomenon do not cause climate change. However, they still create a shift of the seasons about a certain ideal calendar.

What can you say about changes in the ecliptic longitude, ecliptic latitude, direct climbing and decline in all stars, as a result of the precession movement of the earth's axis?

Tasks for independent homework

Name the main planes, lines and points of the heavenly sphere.

Where are the heavenly shovels for an observer located in the northern (southern) hemisphere of the earth?

How are the system of astronomical coordinates are being built?

What is called height and azimuth shining?

What are the equatorial and ecliptic coordinates?

How are direct climbing and clock corner?

How are the declination and the height of the shone at the time of the upper climax?

What is precession and nation?

Why do the stars always enter and enter the same points of the horizon, and the sun and the moon are not?

How does the visible movement of the sun on the heavenly sphere with the movement of the Earth around the Sun?

What is Ecliptic?

What points are invinual and why?

What is the solstice?

What an angle is tilted by an ecliptic to the horizon and why is this angle change during the day?

In which case, the ecliptic may coincide with the horizon?

Apply a handle on the circle depicting the model of the celestial sphere of the point in which the sun is located:

At the applied points to outline the position of the ecliptic. Indicate on the ecliptic (approximately) the position of the Sun on April 21, October 23 and on the day of your birth. Find those listed in the preceding points of the point on the model of the celestial sphere.

Literature

Levitan, E.P. Methods of teaching astronomy in high school / E.P. Levitan. - M.: Enlightenment, 1965. - 227 p.

Malakhov A.A. Physics and Astronomy (competence): study. Manual / A.A. Malakhov; Shadr. State Ped. In-t. - Shadrinsk: Shadd. Print House, 2010. - 163 p.

Major, V.F. How to find out that the earth rotates? / V.F. Majors // Physics. - 2010. - № 2. - P. 45-47.

Myakyshev G.Ya., Bukhovtsev B.B., Sotsky N. N. Physics: studies. For 10 cl. general educational institutions. - M.: Enlightenment, 2010.

Pinsky A.A., Razumovsky V.G., Bugaev A.I. and others. Physics and astronomy: studies for 9 cl. general education. Institutions / ed. A.A. Pinsky, V.G. Razumovsky. - M.: Enlightenment, 2001. - P. 202-212

Randzini, D. Space / D. Randzini; Per. with ital. N. Lebedeva. - M.: LLC "Astrel Publisher", 2004. - 320 p.

Put the chair in the middle of the room and, turning to him face, make several circles around it. And it does not matter that the chair is motionless - it will seem to you that it moves in space, because it will be visible against the background of different fitness items.

Similarly, the land turns around the Sun, and we, the inhabitants of the Earth, it seems that the sun moves against the background of the stars, making a full turn in the sky in one year. Such a movement of the sun is called annual. In addition, the sun, like all other celestial bodies, participates in the daily movement of the sky.

The path among the stars by which the annual movement of the sun is called ecliptic.

Full turnover by ecliptic Sun commits for the year, i.e. Approximately for 365 days, so the sun shifts 360 ° / 365≈1 ° per day.

Since the sun from year to year moves approximately the same path, i.e. The position of the ecliptic among stars changes over time very and very slowly, the ecliptic can be applied to the star of the starry sky:

Here is a purple line - heavenly equator. Above it - the part of the northern hemisphere of the sky, adjacent to the equator, is lower - the equatorial part of the southern hemisphere.

Fat wavy line depicts the annual way of the Sun in the sky, i.e. Ecliptic. Upstairs it is written, what season of the year begins in the northern hemisphere of the Earth, when the sun is in the appropriate sky area.

The image of the sun on the map moves along the ecliptic on the right left.

During the year, the Sun has time to visit 12 zodiacal constellations and in one thing - in Zmeyenosce (from November 29 to December 17),

Four special points are allocated on the ecliptic.

BP - Point of Spring Equinox. The sun, passing through the point of spring equinox, gets from the southern hemisphere of the sky to the North.

LS - the point of the summer solstice, - the point of ecliptic, located in the northern hemisphere of the sky and the most remote from the heavenly equator.

OR - point of autumn equinox. The sun, passing through the point of autumn equinox, gets from the northern hemisphere of the sky to the south.

ZS - the point of the winter solstice, - the point of ecliptic, located in the southern hemisphere of the sky and the most remote from the heavenly equator.

Ecliptic point	The sun is at this point of ecliptic.	Start of astronomical season
Spring equinox
Summer Solstice
Autumn equinox
Winter Solstice

Finally, how to find out what the sun really move across the sky among the stars?

Currently, this is not a problem at all, because The brightest stars are visible in the telescope even during the day, so the movement of the sun among the stars with the help of a telescope can be obtained by wishes.

In the dotelescopic era of astronomers, the length of the shadow of the gnomon was measured - vertical pole, which allowed them to determine the angular distance of the sun to the heavenly equator. In addition, they observed not the sun itself, and the stars, diametrically opposed to the sun, i.e. Those stars that turned out to be above all over the horizon at midnight. As a result, the ancient astronomers determined the position of the sun in the sky and, therefore, the position of the ecliptic among the stars.