Equinox: Six Declinations

Free download. Book file PDF easily for everyone and every device. You can download and read online Equinox: Six Declinations file PDF Book only if you are registered here. And also you can download or read online all Book PDF file that related with Equinox: Six Declinations book. Happy reading Equinox: Six Declinations Bookeveryone. Download file Free Book PDF Equinox: Six Declinations at Complete PDF Library. This Book have some digital formats such us :paperbook, ebook, kindle, epub, fb2 and another formats. Here is The CompletePDF Book Library. It's free to register here to get Book file PDF Equinox: Six Declinations Pocket Guide.

In summary:.

Step 2: Determine the Sun's Equinox Altitude

The sun appears to move along with the celestial sphere on any given day, but follows different circles at different times of the year: most northerly at the June solstice and most southerly at the December solstice. At the equinoxes, the sun's path follows the celestial equator. At the equinoxes, exactly half of the sun's circular path lies above the horizon. But notice that in June, considerably more than half of the circle is above the horizon, while in December, much less than half the circle is visible.

Midnight Sun or Polar Night

This is why, if you live in the north, you have more hours of daylight in June during your summer than in December during your winter. The added hours of daylight are one reason why summer is warmer than winter. But there's another reason that's even more important: the angle of the mid-day sun. Notice from the illustrations above that the noon sun is much higher in June than in December. This means that the sun's rays strike the ground more directly in June. In December, on the other hand, the same amount of energy is diluted over a larger area of ground:.

Join Kobo & start eReading today

The intensity of sunlight striking the ground depends on the sun's angle in the sky. When the sun is at a lower angle, the same amount of energy is spread over a larger area of ground, so the ground is heated less. There is a common misconception that summer is warmer than winter because the sun is closer to us in the summer.


  1. Henrietta`s Journal.
  2. Business Continuity Management?
  3. Equinox – Six Declinations – Book Review.
  4. Learn more about Solar Declination;

Actually the sun's distance hardly changes at all—and in fact, the sun happens to be closest to us in January. Again, the seasonal changes in climate are caused by the varying angle of the sun's rays, together with the varying amount of time that the sun is above our horizon. Although we never see the sun and the stars at the same time, it's not especially hard to figure out which stars and constellations the sun is lined up with on any given day: Just look at the constellations in the east a little before sunrise, or the constellations in the west a little after sunset, and allow for the angle of the sun below your horizon.

The ecliptic is a great circle on the celestial sphere, tipped Its orientation with respect to our horizon changes as the sphere spins around us each day. It has the orientation shown here at noon in December and at midnight in June.

MEASURING THE SKY

If you plot the sun's daily location on a star chart or celestial globe, you'll find that it gradually traces out a great circle, called the ecliptic. So the ecliptic is an imaginary circle around the celestial sphere, centered on us, that marks all the possible locations of the sun with respect to the constellations. Each day, as the sun takes four minutes longer than the constellations to spin around us, it creeps approximately one degree eastward along the ecliptic. It completes the circle in exactly one full year The ecliptic intersects the celestial equator at two opposite points, the sun's locations at the equinoxes.

But the ecliptic is tipped at a The sun reaches the ecliptic's northernmost point at the June solstice, and reaches its southernmost point at the December solstice. The constellations of the zodiac are simply those that happen to lie along the ecliptic. According to the modern official constellation boundaries, however, most of the Scorpius portion of the ecliptic actually lies in the adjacent constellation Ophiuchus. In this degree map of the entire celestial sphere, the north celestial pole is stretched across the top edge and the south celestial pole across the bottom edge.

The celestial equator is marked in blue, and the 12 constellations of the zodiac are outlined. The ecliptic, shown in yellow, marks the sun's annual path among the stars. At the March equinox the sun is at the far right, in Pisces. The sun drifts leftward by about one degree per day, moving first into the northern half of the sky and then, after the September equinox, into the southern half. The sun's location with respect to the stars doesn't depend on your observing location on earth, so you now know enough to figure out how the sun appears to move through the sky from other locations.

If you travel east or west, you'll see the sun rise and set earlier or later, respectively, just like a star would. Again, we partially compensate for this by setting our clocks to different time zones. If you travel north or south, the sun's daily motion is still the same as that of a star seen from your latitude. So at the equinoxes, for example, the sun still follows the celestial equator, while at the solstices, the sun follows a circle that lies If you can visualize the paths of stars on these parts of the celestial sphere, then you can visualize the daily path of the sun.


  • Spree Part Five: Bloodlight.
  • See a Problem?!
  • The Beast and The Maiden.
  • Lingua e identità dell’immigrazione russofona in Italia (Monografie del dip. scienze ling. e lett.) (Italian Edition);
  • Equinox: Six Declinations;
  • So Good;
  • So, for example, as you travel northward from Utah, you'll see the noon sun get lower and lower in the southern sky. Eventually you'll come to a latitude where the noon sun at the December solstice lies on your southern horizon; this latitude, North of the Arctic Circle there will be days around the December solstice when the sun never rises.


    • Enlightening Moments!
    • The Ecliptic: the Sun's Annual Path on the Celestial Sphere!
    • The Night of the Storm.
    • Shortest Day of the Year in the Northern Hemisphere.
    • Astronomy Answers: AstronomyAnswerBook: Seasons.
    • Solar Declination.
    • Navigation menu!
    • What's a little less obvious is that at the Arctic Circle on the June solstice, the sun never sets—it merely grazes the northern horizon at midnight see the illustration below. Still farther north there will be more and more days of darkness in winter and continuous sunlight in summer. At the North Pole, the sun is above the horizon for six straight months March through September , spinning around in horizontal circles, reaching a maximum height of As you travel southward in the northern hemisphere, the noon sun gets higher and higher.

      Equinox: Six Declinations eBook by Richard Freeland - | Rakuten Kobo

      The first qualitative change occurs at This latitude is called the Tropic of Cancer. Farther south, in the so-called tropics, the noon sun will appear in the northern sky for a period of time around the June solstice. At the equator, the noon sun is straight overhead on the equinoxes.

      Astronomy - Ch. 2: Understanding the Night Sky (8 of 23) Understanding Celestial Coordinates

      And after you pass Much farther south is the Antarctic Circle , where the sun never quite rises on the June solstice and never quite sets on the December solstice. This was due in part to the influence of astrology, but later, accurate positions came to be important for determining the physical characteristics of the stars and planets. Accurate positions for the stars was also crucial for commercial and military navigation navigation by the stars has only recently been replaced by the use of satellite systems such as the Global Positioning System.

      http://4840.ru/components/whatsapp-hacken/vedal-handy-sms-mitlesen.php But probably of more importance to you is where to point your telescope or binoculars to find that cool object talked about in the newspaper or astronomy magazine. There are a couple of popular ways of specifying the location of a celestial object. The first is what you would probably use to point out a star to your friend: the altitude-azimuth system.

      Introductory Astronomy:

      The altitude of a star is how many degrees above the horizon it is anywhere from 0 to 90 degrees. The azimuth of a star is how many degrees along the horizon it is and corresponds to the compass direction. For example, a star in the southwest could have an azimuth between degrees and degrees. Since stars change their position with respect to your horizon throughout the night, their altitude-azimuth position changes. Also, observers at different locations looking at the same star at the same time will see it at a different altitude-azimuth position.

      A concise summary of this coordinate system and the numbers involved is given at the end of this section. The second way of specifying star positions is the equatorial coordinate system. This system is very similar to the longitude-latitude system used to specify positions on the Earth's surface. This system is fixed with respect to the stars so, unlike the altitude-azimuth system, a star's position does not depend on the observer's location or time. Because of this, astronomers prefer using this system.

      You will find this system used in astronomy magazines and in most sky simulation computer software.