The Celestial Sphere
review

Vocabulary

celestial sphere		celestial equator		circumpolar
latitude		longitude		meridian
North Celestial		South Celestial		zenith
autumnal (fall) equinox		ecliptic		winter solstice
solar day		summer solstice		vernal (spring) equinox
altitude		azimuth		declination
precession		right ascension

1. Be able to label
a) zenith
b) meridian
c) horizon

2. Which coordinates on the celestial sphere correspond to the terrestrial coordinates
a) latitude
b) longitude
c) equator
d) north pole
e) south pole
f) prime meridian

3. Given the celestial coordinates, be able to locate a star on the star globe.

4. If a star having an RA of 5h crosses the meridian at 9:00PM, what would be the RA of a star crossing the meridian at midnight? Why?

5. What is the astronomical significance of the zodiac constellations and where on the celestial sphere are they found?

6. What will the Sun's declination be on the following dates:
a) June 21?
b) March 21?
c) September 22?
d) December 21?


7. For a given latitude, be able to give the
a) altitude of the north star
b) altitude of the celestial equator
c) the meridian altitude of the sun at the summer solstice
d) the meridian altitude of the sun at the winter solstice
e) the meridian altitude of the sun at the vernal equinox
f) the meridian altitude of the sun at the autumn equinox
g) the declination of a star that would pass through the zenith
h) the range of declinations for stars that would be circumpolar
i) the range of declinations for stars that could never be seen from that location

8. Be able to draw the diurnal paths of the stars for different locations on earth such as
a) the north pole
b) the equator
c) 45o latitude

9. On which day(s )
a) does the sun rise exactly in the east and set exactly in the west?
b) is the sun above the horizon the longest in the northern hemisphere?
c) is the sun above the horizon the shortest time in the northern hemisphere?
d) is the sun above the horizon the longest in the southern hemisphere?
e) is the sun above the horizon the shortest time in the southern hemisphere?
f) does the earth have 12 hours of daylight?

10. Where on earth would the sun
a) be at the zenith on the summer solstice?
b) be at the zenith on the winter solstice?
c) be at the zenith on the vernal and autumn equinox?
d) never set on the summer solstice?
d) never set on the winter solstice?


11. Using the star globe, for a given date and latitude be able to give the
a) declination of the sun
b) azimuth of the sunrise
c) azimuth of the sunset
d) length of the day
e) the meridian altitude of the sun

12. What is precession and what causes it?

13. Has Polaris always been the north star? Why or why not?

14. Why was the sun not in your horoscope zodiac sign when you were born?