SAMPLE HOMEWORK
1.
2.
Fill In the blanks (answers are in parentheses)
Location of Sun
Date
Sun’s right ascension
Sun’s declination
Vernal Equinox
(Summer Solstice)
(Autumnal Equinox)
(Winter Solstice)
(0 degrees)
(23 ½ degrees north)
(0 degrees)
(23 ½ degrees south)
(3/21)
6/21
(9/21)
12/21
(0 hours)
(6 hours)
12 hours
(18 hours)
Due to the orbital motion of the Earth the Sun appears to move (eastward)(direction) along the
(ecliptic) (path name) at the rate of (1) degrees per (day).
3. The Earth’s rotational motion causes the Sun to appear to move (westward) (direction) along a
(diurnal circle) (path name) at a rate of (15) degrees per (hour).
4. Your are located in Gainesville, Florida (Lat. = 30 deg. N, Long. = 82 deg. W)
a. On march 21 the Sun rises (due east) (direction), transits (30) degrees (south) (direction) of
your zenith and sets (due west) (direction).
b. An object having a declination 5 degrees north will rise (north of east) (direction), transit
(25) degrees (south) (direction) of your zenith and will set (north of west) (direction).
c. An object having a declination 20 south will rise (south of east) (direction), transit (50)
degrees (south) (direction) of your zenith and will set (south of west) direction.
5. The right ascension of the Sun on November 26 is __________________. (1620)
6. You are located at 45 deg. N. latitude. The north celestial pole (Polaris) will be elevated (45)
degrees above your (northern) horizon along the (celestial meridian) (name of circle).
7. In Gainesville the mean Sun transits at (1228) (EST), (1328) (EDT).
8. The hour angle of the rising Sun on September 21 is ______________. (18 hours)
9. A given object has a right ascension of 1415 and an hour angle of 1650. What is the sidereal
time? ____________ (0705)
10. The apparent annual motion of the Sun (due to the Earth’s revolution) carries it ________
degrees per day toward the __________ (direction) along the ________ (path).
Answers: one, east, ecliptic
11. On December 21, the Sun is located at the ____________, its declination is ____________ and it
right ascension is _____________. Answers: winter solstice, 23 ½ degrees south, 18 hours
12. If I am located at 10 degrees south latitude and observe an object at 3 degrees south
declination, it will rise in the ________________ (direction), transit ___________ degrees
(direction) of my zenith and set in the ______________ (direction).
Answers: South of east, 7 degrees, North, South of west
13. I am located at 40 degrees north latitude. I see a star transit 15 degrees south of my zenith.
What is its declination?
Answer: 25 degrees north
14. I am in Santiago, Chile (30 degrees south latitude). What stars will be circumpolar?
Answer: All having declination greater than 60 degrees south
15. I am located at 110 degrees west longitude. What time zone am I in? At what zone time will the
mean sun transit? Answers: Mountain Standard Time, 12:20 pm
16. The Sun has a declination of 10 degrees north. I observe it to transit 22 degrees south of my
zenith. What is my latitude? Answer: 32 degrees north
17. The 3rd quarter moon is just setting. The time is __________. Answer: 12 noon
18. The waxing gibbous moon transits at about ________. Answer: 9 pm
19. The full moon will transit in three hours. The time is ___________. Answer: 9 pm
20. It is 6 am. The moon is just rising. What is the phase of the Moon? Answer: new
21. The time is 6pm. The moon will set in 3 hours. What is the phase of the Moon?
Answer: waxing crescent
22. It is 9 pm August 21. The moon will rise in 3 hours.
a. What is the phase of the moon? Answer: 3rd quarter
b. What is the right ascension of the Moon? Answer: 4 hours
23. I observe a lunar eclipse on September 21.
a. What is the phase of the Moon? Answer: full
b. What is the right ascension of the Moon? Answer: 0 hours
c. What is the declination of the Moon? Answer 0 degrees
If the eclipse occurs at sunset what are the:
d. Hour angle of the Moon? Answer: 18 hours
e. Azimuth of the Moon? Answer: 90 degrees
f. Zenith angle of the moon? Answer: 90 degrees
g. What is the Sidereal Time? Answer: 18 hours