Astronomy
When the light comes and goes, its z = 90 °, h = 0e, and the azimuths of the points of sunrise and sunset depend on the declination and the latitude of the place lights up. At the time of upper culmination zenith distance of the light of the minimum, maximum altitude and the azimuth A = 0 (if the star culminates south of the zenith), or A = 180e (unless it culminates from the zenith to the north). At the time of the lower culmination of the zenith distance of lights reaches its maximum value, the height - the minimum, and the azimuth A = 180e, or A = 0e (if the lower culmination of the nadir occurs between Z 'and the south pole of the world P'). Hence, from the lower to the upper culmination zenith distance of the light decreases, and the height increases, from the upper to the lower peak, by contrast, the zenith distance increases, the height decreases. At the same azimuth lights will also vary within certain limits. Thus, the horizontal coordinates of luminaries (z, h and A) are continually changing as a result of the rotation of the celestial sphere, and if the light has always connected with the sphere (ie, its declination d and a right ascension remain constant), then its horizontal coordinates take their previous values ??when the sphere will make one revolution. Since the daily parallel bodies at all latitudes of the Earth (except the poles) are inclined to the horizon, the horizontal coordinates vary unevenly, even for a uniform daily rotation of the celestial sphere. Altitude h, and its zenith distance z more slowly varying near the meridian, ie, at the upper or lower culmination. Azimuth is shining A, on the contrary, in these moments varies most rapidly. Local luminaries angle t (in the first equatorial coordinate system), like the azimuth A, is constantly changing. At the time of upper culmination of his lights t = 0. At the time of the lower peak hour angle of the lights t = 180e, or 12h. But, in contrast to the azimuth, hour angle luminaries (if the declination d and a direct ascent remain constant) change uniformly because they counted on the celestial equator, and the uniform rotation of the celestial sphere angles are proportional to changes in hourly time intervals, ie increment of time equal to the angle of rotation angle of the celestial sphere. The uniformity of the angles change time is very important in the measurement of time. Altitude h, or the zenith distance z at the climax depends on the declination shone d and latitude of the observer j. Drawing directly from (7): 1) If the declination shone M1 d <j, then it culminates to the south of the zenith at the zenith distance z = j - d, (1.6) or the height h = 90 ° - j + d; (1.7 ) 2) if d = j, then the star culminates at the zenith, and then z = 0 (1.8) and h = + 90 °, (1.9) 3) if d> j, then the star of M2 in the upper peak is located to the north of the zenith to the zenith distance z = d - j, (1.10) or the height h = 90 ° + j - d. (1.11) 4) Finally, at the time of the lower culmination of the zenith distance z = M3 lights 180e - j - d, (1.12) a height h = d - (90 ° - j) = j + d - 90 °. (1.13) is known from observations (see § 8) that at a given latitude j each star always rises (or sets) at the same point of the horizon, the height it is also always the same meridian. We can therefore conclude that the declination of stars do not vary over time (at least visibly). The point of sunrise and sunset, moon and planets, as well as their height in the meridian at different days of the year - are different. Consequently, the declination of these stars are continuously changing over time.
- Astronomy Fun Facts
For many people astronomy is an interesting science filled with many astronomy fun facts. Everything from the size and temperature of our own star, the Sun, to the makeup of distant planets is recorded. People can get a lot of enjoyment from all of this...
- The Ecliptic. Ecliptic Coordinate System
Measurements of the zenith distance or altitude of the sun at noon (ie, at the time of upper culmination) at the same latitude was found that the declination of the sun throughout the year varies between 23 e 27 'up-23e27' twice a year passing...
- Islamic Astronomy
Islamic Astronomy - history and value of the Arabian astronomy In this article the short review of Islamic astronomy which also name Arabian is given. Before occurrence of astronomy as a science, Islamic Arabs relied on the empirical knowledge of stars....
- Saturn's Vortex And Rings.
The Cassini spacecraft captures three magnificent sights at once: Saturn's north polar vortex and hexagon along with its expansive rings. The hexagon, which is wider than two Earths, owes its appearance to the jet stream that forms its perimeter....
- Ptolemy's Geocentric Theory
Ptolemy proposed his Geocentric theory in the 2nd century A.D. What he did was just an elaboration of already existing idea that earth was in the center of universe, proposed by Aristotle, in to a complete cosmological model. According to his theory,...
Astronomy
Changing the origin of light in the diurnal motion
- Astronomy Fun Facts
For many people astronomy is an interesting science filled with many astronomy fun facts. Everything from the size and temperature of our own star, the Sun, to the makeup of distant planets is recorded. People can get a lot of enjoyment from all of this...
- The Ecliptic. Ecliptic Coordinate System
Measurements of the zenith distance or altitude of the sun at noon (ie, at the time of upper culmination) at the same latitude was found that the declination of the sun throughout the year varies between 23 e 27 'up-23e27' twice a year passing...
- Islamic Astronomy
Islamic Astronomy - history and value of the Arabian astronomy In this article the short review of Islamic astronomy which also name Arabian is given. Before occurrence of astronomy as a science, Islamic Arabs relied on the empirical knowledge of stars....
- Saturn's Vortex And Rings.
The Cassini spacecraft captures three magnificent sights at once: Saturn's north polar vortex and hexagon along with its expansive rings. The hexagon, which is wider than two Earths, owes its appearance to the jet stream that forms its perimeter....
- Ptolemy's Geocentric Theory
Ptolemy proposed his Geocentric theory in the 2nd century A.D. What he did was just an elaboration of already existing idea that earth was in the center of universe, proposed by Aristotle, in to a complete cosmological model. According to his theory,...