Perhaps on this day you will have to make a choice between “black” and “white”, without any halftones. If you hesitate and cannot take an important step, then either postpone making a decision for a while, or consult with those you trust.

Things on the love front can go uphill. Very soon you yourself will notice the changes that will begin to occur in your soul and consciousness. Although this does not mean that you will meet a new partner if your heart is already taken. You can reconsider your relationship with a person you think you know quite well.

If now you are destined to meet a pleasant person of the opposite sex, then do not rush to be frank and invite him to visit. Soon you will realize that this is not your soul mate. But for negotiations, signing business papers and important meetings, this day is quite successful.

Although this day will be filled with bustle, it cannot be said that it will be empty. Along the way, you will have time to solve important issues as well. You should not negotiate with your superiors. It will be better if your paths do not cross.

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The day may turn out to be successful provided that you do not start arguments and quarrels with loved ones. Engage in social activities or activities that give you pleasure. You will be able to accomplish a lot, and you will feel proud of yourself. Remember: now almost everything depends on you.

It is likely that changes for the better await you in your professional field. Possible promotion. Start preparing for pleasant changes and collecting the necessary information. In love affairs, at this stage you may get a second wind. And some people will be able to find their love.

You will have a huge supply of strength and energy, so don’t waste precious time, but start solving issues that previously seemed difficult. Everything should work out for you now. Treat yourself to some shopping. Allow yourself to buy things that you have long dreamed of.

The day will require a huge investment - both physical and emotional. Treat everything that happens as a life exam that you need to pass. Try to do pleasant things in your free moments that will allow you to relax and get away from worries. By the way: you are on the verge of very pleasant events.

You can outline the most serious matters that you have not wanted to take on for a long time. Now I can do a lot - if I have the desire. If someone asks you for advice or help (not financial), do not refuse the person the service, unless, of course, it is within your power and competence. Be careful with money - keep your wallet with you.

In the professional sphere, now everything will happen according to the planned schedule. Try to pay more attention to your health, spend more time in the fresh air, especially in the company of people you like. In love, only pleasant emotions await you. However, do not forget that you are not the crown of creation; you should not test the patience of your other half.

Now on the path of life you may face a test that you will have to pass. Moreover, a lot will depend on how you cope with this task. Don't ask people you don't trust for help. They are the ones who are currently capable of mixing your cards.

The day is favorable in many respects, so make plans, implement bold ideas and do not doubt success. When working, try to adhere to a comfortable rhythm; do not allow your colleagues to rush or delay you. A change of scenery will be beneficial. Pleasant meetings and a wonderful holiday in good company await you.

© The horoscope for today, September 23, 2017, was compiled by astrologer Marina Alexandrova specifically for the site.

Lunar calendar, sunrise, sunset and moon data for September 23, 2017 are given for Moscow and the Moscow region.

§ 52. Apparent annual motion of the Sun and its explanation

Observing the daily movement of the Sun throughout the year, one can easily notice a number of features in its movement that differ from the daily movement of stars. The most typical of them are the following.

1. The place of sunrise and sunset, and therefore its azimuth, changes from day to day. Starting from March 21 (when the Sun rises at the point of the east and sets at the point of the west) to September 23, the sun rises in the north-east quarter, and sunset - in the north-west. At the beginning of this time, the sunrise and sunset points move north and then in the opposite direction. On September 23, just like on March 21, the Sun rises at the east point and sets at the west point. Starting from September 23 to March 21, a similar phenomenon will repeat in the southeast and southwest quarters. The movement of sunrise and sunset points has a one-year period.

The stars always rise and set at the same points on the horizon.

2. The meridional altitude of the Sun changes every day. For example, in Odessa (average = 46°.5 N) on June 22 it will be greatest and equal to 67°, then it will begin to decrease and on December 22 it will reach its lowest value of 20°. After December 22, the meridional altitude of the Sun will begin to increase. This is also a one-year phenomenon. The meridional altitude of stars is always constant. 3. The duration of time between the culminations of any star and the Sun is constantly changing, while the duration of time between two culminations of the same stars remains constant. So, at midnight we see those constellations culminating that are currently located on the opposite side of the sphere from the Sun. Then some constellations give way to others, and over the course of a year at midnight all the constellations will culminate in turn.

4. The length of the day (or night) is not constant throughout the year. This is especially noticeable if you compare the length of summer and winter days in high latitudes, for example in Leningrad. This happens because the time the Sun is above the horizon varies throughout the year. The stars are always above the horizon for the same amount of time.

Thus, the Sun, in addition to the daily movement performed jointly with the stars, also has a visible movement around the sphere with an annual period. This movement is called visible the annual movement of the Sun across the celestial sphere.

We will get the most clear idea of ​​this movement of the Sun if we determine its equatorial coordinates every day - right ascension a and declination b. Then, using the found coordinate values, we plot the points on the auxiliary celestial sphere and connect them with a smooth curve. As a result, we obtain 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 along which the Sun moves is called the ecliptic. The plane of the ecliptic is inclined to the plane of the equator at a constant angle g = =23°27", which is called the angle of inclination ecliptic to equator(Fig. 82).

Rice. 82.

The apparent annual movement of the Sun along the ecliptic occurs in the direction opposite to the rotation of the celestial sphere, that is, from west to east. The ecliptic intersects the celestial equator at two points, which are called the equinox points. The point at which the Sun passes from the southern hemisphere to the northern, and therefore changes the name of declination from southern to northern (i.e. from bS to bN), is called the point spring equinox and is designated by the Y icon. This icon denotes the constellation Aries, in which this point was once located. Therefore, it is sometimes called the Aries point. Currently, point T is located in the constellation Pisces.

The opposite point at which the Sun passes from the northern hemisphere to the southern and changes the name of its declination from b N to b S is called point of the autumnal equinox. It is designated by the symbol of the constellation Libra O, in which it was once located. Currently, the autumn equinox point is in the constellation Virgo.

Point L is called summer point, and point L" - a point winter solstice.

Let's follow the apparent movement of the Sun along the ecliptic throughout the year.

The Sun arrives at the vernal equinox on March 21st. The right ascension a and declination b of the Sun are zero. Throughout the globe, the Sun rises at point O st and sets at point W, and day is equal to night. Starting March 21, the Sun moves along the ecliptic towards the summer solstice point. The right ascension and declination of the Sun are continuously increasing. It is astronomical spring in the northern hemisphere, and autumn in the southern hemisphere.

On June 22, approximately 3 months later, the Sun comes to the summer solstice point L. The direct ascension of the Sun is a = 90°, a declination b = 23°27"N. In the northern hemisphere, astronomical summer begins (the longest days and shortest nights), and in the south - winter (longest nights and shortest days)... With the further movement of the Sun, its northern declination begins to decrease, and its right ascension continues to increase.

About three more months later, on September 23, the Sun comes to the point of the autumnal equinox Q. The direct ascension of the Sun is a=180°, declination b=0°. Since b = 0 ° (like March 21), then for all points on the earth’s surface the Sun rises at point O st and sets at point W. Day will be equal to night. The name of the declination of the Sun changes from northern 8n to southern - bS. In the northern hemisphere, astronomical autumn begins, and in the southern hemisphere, spring begins. With further movement of the Sun along the ecliptic to the winter solstice point U, declination 6 and right ascension aO increase.

On December 22, the Sun comes to the winter solstice point L". Right ascension a=270° and declination b=23°27"S. Astronomical winter begins in the northern hemisphere, and summer begins in the southern hemisphere.

After December 22, the Sun moves to point T. The name of its declination remains southern, but decreases, and its right ascension increases. Approximately 3 months later, on March 21, the Sun, having completed a full revolution along the ecliptic, returns to the point of Aries.

Changes in the right ascension and declination of the Sun do not remain constant throughout the year. For approximate calculations, the daily change in the right ascension of the Sun is taken equal to 1°. The change in declination per day is taken to be 0°.4 for one month before the equinox and one month after, and the change is 0°.1 for one month before the solstices and one month after the solstices; the rest of the time, the change in solar declination is taken to be 0°.3.

The peculiarity of changes in the right ascension of the Sun plays an important role when choosing the basic units for measuring time.

The vernal equinox point moves along the ecliptic towards the annual movement of the Sun. Its annual movement is 50", 27 or rounded 50",3 (for 1950). Consequently, the Sun does not reach its original place relative to the fixed stars by an amount of 50",3. For the Sun to travel the indicated path, it will take 20 mm 24 s. For this reason, spring

It occurs before the Sun completes its visible annual motion, a full circle of 360° relative to the fixed stars. The shift in the moment of the onset of spring was discovered by Hipparchus in the 2nd century. BC e. from observations of stars that he made on the island of Rhodes. He called this phenomenon the anticipation of the equinoxes, or precession.

The phenomenon of moving the vernal equinox point caused the need to introduce the concepts of tropical and sidereal years. The tropical year is the period of time during which the Sun makes a full revolution across the celestial sphere relative to the point of the vernal equinox T. “The duration of the tropical year is 365.2422 days. The tropical year is consistent with natural phenomena and precisely contains the full cycle of the seasons of the year: spring, summer, autumn and winter.

A sidereal year is the period of time during which the Sun makes a complete revolution across the celestial sphere relative to the stars. The length of a sidereal year is 365.2561 days. The sidereal year is longer than the tropical year.

In its apparent annual movement across the celestial 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 the names of animals. The strip of sky along the ecliptic formed by these constellations was called the Zodiac (circle of animals), and the constellations were called zodiacal.

According to the seasons of the year, the Sun passes through the following constellations:

From the joint movement of the annual Sun along the ecliptic and the daily movement due to the rotation of the celestial sphere, the general movement of the Sun along a spiral line is created. The extreme parallels of this line are located on both sides of the equator at distances of = 23°.5.

On June 22, when the Sun describes the extreme diurnal parallel in the northern celestial hemisphere, it is in the constellation Gemini. In the distant past, the Sun was in the constellation Cancer. On December 22, the Sun is in the constellation Sagittarius, and in the past it was in the constellation Capricorn. Therefore, the northernmost celestial parallel was called the Tropic of Cancer, and the southern one was called the Tropic of Capricorn. The corresponding terrestrial parallels with latitudes cp = bemach = 23°27" in the northern hemisphere were called the Tropic of Cancer, or the northern tropic, and in the southern hemisphere - the Tropic of Capricorn, or the southern tropic.

The joint movement of the Sun, which occurs along the ecliptic with the simultaneous rotation of the celestial sphere, has a number of features: the length of the daily parallel above and below the horizon changes (and therefore the duration of day and night), the meridional heights of the Sun, the points of sunrise and sunset, etc. etc. All these phenomena depend on the relationship between the geographic latitude of a place and the declination of the Sun. Therefore, for an observer located at different latitudes, they will be different.

Let's consider these phenomena at some latitudes:

1. The observer is at the equator, cp = 0°. The axis of the world lies in the plane of the true horizon. The celestial equator coincides with the first vertical. The diurnal parallels of the Sun are parallel to the first vertical, therefore the Sun in its daily movement never crosses the first vertical. The sun rises and sets daily. Day is always equal to night. The Sun is at its zenith twice a year - on March 21 and September 23.

Rice. 83.

2. The observer is at latitude φ
3. The observer is at latitude 23°27"
4. The observer is at latitude φ > 66°33"N or S (Fig. 83). The belt is polar. Parallels φ = 66°33"N or S are called polar circles. In the polar zone, polar days and nights can be observed, that is, when the Sun is above the horizon for more than a day or below the horizon for more than a day. The longer the polar days and nights, the greater the latitude. The sun rises and sets only on those days when its declination is less than 90°-φ.

5. The observer is at the pole φ=90°N or S. The axis of the world coincides with the plumb line and, therefore, the equator with the plane of the true horizon. The observer's meridian position will be uncertain, so parts of the world are missing. During the day, the Sun moves parallel to the horizon.

On the days of the equinoxes, polar sunrises or sunsets occur. On the days of the solstices, the height of the Sun reaches its greatest values. The altitude of the Sun is always equal to its declination. The polar day and polar night last for 6 months.

Thus, due to various astronomical phenomena caused by the combined daily and annual movement of the Sun at different latitudes (passage through the zenith, polar day and night phenomena) and the climatic features caused by these phenomena, the earth's surface is divided into tropical, temperate and polar zones.

Tropical zone is the part of the earth's surface (between latitudes φ=23°27"N and 23°27"S) in which the Sun rises and sets every day and is at its zenith twice during the year. The tropical zone occupies 40% of the entire earth's surface.

Temperate zone called the part of the earth's surface in which the Sun rises and sets every day, but is never at its zenith. There are two temperate zones. In the northern hemisphere, between latitudes φ = 23°27"N and φ = 66°33"N, and in the southern hemisphere, between latitudes φ=23°27"S and φ = 66°33"S. Temperate zones occupy 50% of the earth's surface.

Polar belt called the part of the earth's surface in which polar days and nights are observed. There are two polar zones. The northern polar belt extends from latitude φ = 66°33"N to the north pole, and the southern one - from φ = 66°33"S to the south pole. They occupy 10% of the earth's surface.

For the first time, the correct explanation of the visible annual movement of the Sun across the celestial sphere was given by Nicolaus Copernicus (1473-1543). He showed that the annual movement of the Sun across the celestial sphere is not its actual movement, but only an apparent one, reflecting the annual movement of the Earth around the Sun. The Copernican world system was called heliocentric. According to this system, at the center of the solar system is the Sun, around which the planets move, including our Earth.

The Earth simultaneously participates in two movements: it rotates around its axis and moves in an ellipse around the Sun. The rotation of the Earth around its axis causes the cycle of day and night. Its movement around the Sun causes the change of seasons. The combined rotation of the Earth around its axis and the movement around the Sun causes the visible movement of the Sun across the celestial sphere.

To explain the apparent annual movement of the Sun across the celestial sphere, we will use Fig. 84. The Sun S is located in the center, around which the Earth moves counterclockwise. The earth's axis remains unchanged in space and makes an angle with the ecliptic plane equal to 66°33". Therefore, the equator plane is inclined to the ecliptic plane at an angle e=23°27". Next comes the celestial sphere with the ecliptic and the signs of the Zodiac constellations marked on it in their modern location.

The Earth enters position I on March 21. When viewed from the Earth, the Sun is projected onto the celestial sphere at point T, currently located in the constellation Pisces. The declination of the Sun is 0°. An observer located at the Earth's equator sees the Sun at its zenith at noon. All earthly parallels are half illuminated, so at all points on the earth's surface day is equal to night. Astronomical spring begins in the northern hemisphere, and autumn begins in the southern hemisphere.

Rice. 84.

The Earth enters position II on June 22. Declination of the Sun b=23°,5N. When viewed from Earth, the Sun is projected into the constellation Gemini. For an observer located at latitude φ=23°.5N, (The sun passes through the zenith at noon. Most of the daily parallels are illuminated in the northern hemisphere and a smaller part in the southern hemisphere. The northern polar zone is illuminated and the southern one is not illuminated. In the northern, the polar day lasts, and in the southern hemisphere it is polar night.In the northern hemisphere of the Earth, the rays of the Sun fall almost vertically, and in the southern hemisphere - at an angle, so astronomical summer begins in the northern hemisphere, and winter in the southern hemisphere.

The Earth enters position III on September 23. The declination of the Sun is bo = 0 ° and it is projected at the point of Libra, which is now located in the constellation Virgo. An observer located at the equator sees the Sun at its zenith at noon. All earthly parallels are half illuminated by the Sun, so at all points on the Earth day is equal to night. In the northern hemisphere, astronomical autumn begins, and in the southern hemisphere, spring begins.

On December 22, the Earth comes to position IV. The Sun is projected into the constellation Sagittarius. Declination of the Sun 6=23°.5S. In the southern hemisphere, more of the diurnal parallels are illuminated than in the northern hemisphere, so in the southern hemisphere the day is longer than the night, and in the northern hemisphere it is vice versa. The sun's rays fall almost vertically into the southern hemisphere, and at an angle into the northern hemisphere. Therefore, astronomical summer begins in the southern hemisphere, and winter in the northern hemisphere. The sun illuminates the southern polar zone and does not illuminate the northern one. The southern polar zone experiences polar day, while the northern zone experiences night.

Corresponding explanations can be given for other intermediate positions of the Earth.

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To the question about sunrise and sunset times on September 23 asked by the author Spica the best answer is Observing the daily movement of the Sun throughout the year, one can easily notice a number of features in its movement that differ from the daily movement of stars. The most typical of them are the following.
1. The place of sunrise and sunset, and therefore its azimuth, changes from day to day. Starting from March 21 (when the Sun rises at the point of the east and sets at the point of the west) to September 23, the sun rises in the north-east quarter, and sunset - in the north-west. At the beginning of this time, the sunrise and sunset points move north and then in the opposite direction. On September 23, just like on March 21, the Sun rises at the east point and sets at the west point. Starting from September 23 to March 21, a similar phenomenon will repeat in the southeast and southwest quarters. The movement of sunrise and sunset points has a one-year period.
The stars always rise and set at the same points on the horizon.
2. The meridional altitude of the Sun changes every day. For example, in Odessa (average = 46°.5 N) on June 22 it will be greatest and equal to 67°, then it will begin to decrease and on December 22 it will reach its lowest value of 20°. After December 22, the meridional altitude of the Sun will begin to increase. This is also a one-year phenomenon. The meridional altitude of stars is always constant. 3. The duration of time between the culminations of any star and the Sun is constantly changing, while the duration of time between two culminations of the same stars remains constant. So, at midnight we see those constellations culminating that are currently located on the opposite side of the sphere from the Sun. Then some constellations give way to others, and over the course of a year at midnight all the constellations will culminate in turn.
4. The length of the day (or night) is not constant throughout the year. This is especially noticeable if you compare the length of summer and winter days in high latitudes, for example in Leningrad. This happens because the time the Sun is above the horizon varies throughout the year. The stars are always above the horizon for the same amount of time.
Thus, the Sun, in addition to the daily movement performed jointly with the stars, also has a visible movement around the sphere with an annual period. This movement is called the apparent annual movement of the Sun across the celestial sphere.
We will get the most clear idea of ​​this movement of the Sun if we determine its equatorial coordinates every day - right ascension a and declination b. Then, using the found coordinate values, we plot the points on the auxiliary celestial sphere and connect them with a smooth curve. As a result, we obtain 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 along which the Sun moves is called the ecliptic. The plane of the ecliptic is inclined to the plane of the equator at a constant angle g = = 23°27", which is called the angle of inclination of the ecliptic to the equator