Sunday, November 25, 2007

ASTRONOMY #6

1. The zenith is the point on the celestial sphere that is ? directly over the observer.

2. 90 degree's - Ho = ? zenith distance.

3. At upper transit, if the zenith distance is 34°, the geographical distance from the observer to a body's GP is ? 2040 miles

4. The difference of latitude (1) between the geographic position (GP) and your position, at the time of upper transit, is represented by ? zenith distance

5. Zenith distance is equal to ? 90° - Ho

6. If the Sun's observed altitude is 27°12', the zenith distance is ? 62°48'

7. If the Sun's observed altitude is 47°50', the zenith distance is ? 42°10'

8. If the Sun's observed altitude is 54°30', what is the zenith distance ? 35°30'

9. In working out a local apparent noon sight for your latitude, you subtract the Ho from 90°. The 90° represents the angular distance from ? your horizon to your zenith

10. In the horizon system of coordinates what is equivalent to the poles on the Earth ? Zenith, nadir

11. In the celestial equator system of coordinates what is NOT equivalent to the longitude of the Earth system of coordinates ? Zn

12. In the celestial equator system of coordinates, what is comparable to latitude on the terrestrial sphere ? Declination

13. The arc of an hour circle between the celestial equator and a point on the celestial sphere, measured northward or southward through 90°, is the ? declination

14. The small circle of the celestial sphere parallel to the celestial equator, and transcribed by the daily motion of the body, is called the ? parallel of declination

15. The daily path of a celestial body that is parallel to the celestial equator is the ? diurnal circle

16. The path of a celestial body during its daily apparent revolution around the Earth is called its ? diurnal circle

17. In the celestial equator system of coordinates what is equivalent to the longitude of the Earth system of coordinates? Greenwich hour angle

18. The GHA of a star ? increases at a rate of approximately 15° per hour

19. In the celestial equator system of coordinates what is the equivalent to the meridians of the Earth system of coordinates ? Hour circles

20. In the celestial equator system of coordinates what is equivalent to the colatitude of the Earth system of coordinates ? Polar distance