Declination

1. Declination- Angle of the Sun Finding the angle of an object above or below the equator

2. Declination Declination is the latitudinal part of the equatorial coordinate system, which is used to map celestial objects. Declination can be used to find the angle of a celestial object above or below the equator, such as the sun.

3. Key Terms In the equatorial coordinate system, there are several key terms used. The ecliptic is similar to the equator , but is not tilted at an angle. Right Ascension is used to measure longitudinal angles. Often these are called “celestial,” such as the celestial equator .

4. Practical Uses Measuring declination is primarily used for mapping celestial objects. It can be used for the sun to find the angle of sunlight for a position on earth.

5. Finding Declination There are relatively simple equations which can be used to find declination. The equation can be used, where d = the day of the year. With this equation, the day October 30, which is the 303 rd day of the year, has an approximate declination angle of -19.11˚.

6. Sources "Declination -." Wikipedia, the free encyclopedia . Web. 02 Nov. 2009. http:// en.wikipedia.org/wiki/Declination . "Declination Angle of the Sun." PVCDROM . Web. 02 Nov. 2009. http://pvcdrom.pveducation.org/SUNLIGHT/DECLIN.HTM . "Equatorial Coordinate." Web. http://hyperphysics.phy-astr.gsu.edu/hbase/solar/imgsol/eclip3.gif .