Questions on Celestial Phenomena


Following are some questions on the celestial sphere and celestial phenomena. They're in the same format as the ones on the hour tests and the final. As always, the answer "NVA" should NOT be selected since it stands for "Not a Valid Answer." The correct answers are listed at the end.

1. The object at the center of the (imaginary) celestial sphere is the
(1) north celestial pole
(2) Earth
(3) zenith
(4) NVA
(5) Sun

2. The circle on the celestial sphere midway between the north and south celestial poles is the
(1) NVA
(2) ecliptic
(3) celestial equator
(4) NVA
(5) horizon

3. The points on the celestial sphere directly above the Earth's poles are
(1) the zenith and the nadir
(2) NVA
(3) the equinoxes
(4) the celestial poles
(5) NVA

4. The imaginary point directly above the observer's head is called the
(1) zenith
(2) north celestial pole
(3) NVA
(4) NVA
(5) nadir

5. The boundary between the ground and the sky (i.e., the part of the celestial sphere blocked out by the Earth and the part that is visible) is termed the
(1) NVA
(2) equator
(3) horizon
(4) celestial meridian
(5) NVA

6. In the coordinate system used to locate an object in the sky for a particular location on the Earth the coordinate measured around the horizon is called
(1) right ascension
(2) declination
(3) azimuth
(4) altitude
(5) NVA

7. In the coordinate system used to locate an object in the observer's sky (i.e., in the altazimuth coordinate system), the coordinate that is called altitude is measured
(1) vertically from the horizon to the given object in degrees
(2) horizontally from the north point on the horizon around towards east in degrees
(3) NVA
(4) NVA
(5) vertically from the zenith down to the object in degrees

8. The imaginary half-circle which runs from the north point on the horizon through the zenith to the south point is the
(1) celestial meridian
(2) horizon
(3) NVA
(4) NVA
(5) ecliptic

9. The imaginary point in the northern sky around which the stars seem to circle here in Gainesville is the
(1) zenith
(2) NVA
(3) north celestial pole
(4) south celestial pole
(5) NVA

10. In the southern sky as seen here in Gainesville, the daily motion causes the stars to move
(1) NVA
(2) NVA
(3) in small circles around the celestial pole
(4) in broad arcs from east to west
(5) straight up in the east and straight down in the west

11. At the North Pole, the stars
(1) circle around the sky parallel to the horizon
(2) NVA
(3) rise straight up in the east and set straight down in the west
(4) NVA
(5) NVA

12. At the Equator, the stars
(1) circle around the sky parallel to the horizon
(2) rise straight up in the east and set straight down in the west
(3) NVA
(4) rise and set at an oblique angle to the horizon
(5) NVA

13. The interval of time during which a star crosses the celestial meridian and comes back to cross it again is termed the
(1) NVA
(2) solar day
(3) sidereal month
(4) NVA
(5) sidereal day

14. The rule for locating the celestial pole in the observer's sky at a particular location on the Earth is
(1) NVA
(2) altitude of pole = observer's latitude
(3) altitude of pole = 90 degrees - observer's latitude
(4) altitude of pole = observer's longitude
(5) azimuth of pole = observer's longitude

15. The circle around the celestial sphere which is the Sun's apparent track during the year is called the
(1) ecliptic
(2) celestial equator
(3) NVA
(4) solway
(5) NVA

16. The gnomon is a vertical pole whose shadow can be used to track the Sun in the sky. Its shadow is shortest at noon (apparent, not by the clock). The fact that the length of the shadow at noon changes over the course of the year implies that
(1) NVA
(2) the Sun moves in the N-S direction during the year
(3) the Sun moves in the E-W direction with respect to the fixed stars during the year
(4) the Sun expands and contracts during the year
(5) NVA

17. Which of the following is not evidence of the Sun's motion eastwards along the ecliptic?
(1) the sidereal day is shorter than the solar day
(2) NVA
(3) different constellations are visible over the course of the year
(4) NVA
(5) the tropical year is shorter than the sidereal year

18. The point at which the Sun crosses the celestial equator moving northwards (from S to N) is termed the
(1) autumnal equinox
(2) NVA
(3) NVA
(4) summer solstice
(5) vernal equinox

19. The phrase "Sun standing still," which refers not to the Sun literally "freezing" in the sky but rather its points of rising and setting on the horizon pausing, is associated with
(1) NVA
(2) the equinoxes
(3) NVA
(4) the solstices
(5) the culminations

20. The approximate date of the winter solstice is
(1) Mar. 21
(2) Sept. 21
(3) Dec. 21
(4) [depends on which hemisphere one is in]
(5) NVA

21. In the Southern Hemisphere (and outside the tropics) the Sun's noon altitude is greatest at the time of the
(1) NVA
(2) winter solstice
(3) summer solstice
(4) NVA
(5) equinoxes

22. The Sun's setting point on the horizon is farthest north of west at the time of
(1) summer solstice
(2) winter solstice
(3) NVA
(4) NVA
(5) [depends on which hemisphere one is in]

23. The equatorial coordinate right ascension is measured
(1) north or south from the celestial equator in units of angle (degrees etc.)
(2) NVA
(3) eastwards from the vernal equinox along the celestial equator in units of time (hours etc.)
(4) east or west from the vernal equinox along the ecliptic in units of angle (degrees etc.)
(5) NVA

24. The equatorial coordinate declination is measured
(1) NVA
(2) north or south of the celestial equator in units of angle (degrees etc.)
(3) north or south of the ecliptic in units of angle (degrees etc.)
(4) NVA
(5) east or west of the vernal equinox along the celestial equator in units of angle (degrees etc.)

25. The time interval for the Sun to go from the vernal equinox around the ecliptic and back to the vernal equinox is called the
(1) tropical year
(2) NVA
(3) sidereal year
(4) sidereal month
(5) NVA

26. The difference between the tropical year and the sidereal year is caused by
(1) regression of the nodes
(2) the Sun's motion along the ecliptic
(3) NVA
(4) NVA
(5) precession of the equinoxes

27. Precession causes the north celestial pole to move around the celestial sphere (with respect to the fixed stars)
(1) back and forth along an arc
(2) NVA
(3) in a large circle
(4) along the ecliptic
(5) NVA

28. When the Sun moves into the vicinity of an object on the celestial sphere, that object disappears from view because of the Sun's glare. The term heliacal rising refers to an object's
(1) NVA
(2) last appearance in the evening sky before diappearing
(3) NVA
(4) rising with the Sun
(5) first appearance in the morning sky before sunrise after having been invisible

29. Heliacal risings of fixed stars occur at intervals of
(1) the star's synodic period
(2) the sidereal year
(3) the tropical year
(4) NVA
(5) NVA

30. The most obvious cycle that the Moon goes through is that of the
(1) synodic month
(2) NVA
(3) NVA
(4) sidereal month
(5) nodical month

31. The Moon's phase midway between first quarter and full is
(1) waxing crescent
(2) waning gibbous
(3) NVA
(4) waxing gibbous
(5) waning crescent

32. The Moon's nodes are the points of intersection of its path around the celestial sphere with the
(1) celestial equator
(2) ecliptic
(3) NVA
(4) precession circle
(5) NVA

33. When the Moon is at third or last quarter, it will rise at approximately
(1) noon
(2) 6 pm
(3) midnight
(4) NVA
(5) 6 am

34. At the ascending node the Moon is moving
(1) NVA
(2) N to S
(3) S to N
(4) NVA
(5) NVA

35. Regression of the Moon's nodes refers to their shifting
(1) eastwards along the ecliptic
(2) NVA
(3) westwards along the celestial equator
(4) eastwards along the celestial equator
(5) westwards along the ecliptic

36. Because of regression the
(1) NVA
(2) NVA
(3) sidereal month is longer than the nodical month
(4) sidereal month is shorter than the synodic month
(5) sidereal month is shorter than the nodical month

37. The Moon's minor standstills occur when the Moon rises and sets
(1) over the widest range along the horizon
(2) NVA
(3) at the same point on the horizon for an entire month
(4) NVA
(5) over the narrowest range along the horizon

38. The Moon's major standstills take place when its ascending node is located at the
(1) summer solstice
(2) autumnal equinox
(3) winter solstice
(4) vernal equinox
(5) NVA

39. The time interval between occurrence of the Moon's major standstills and its minor standstills is
(1) NVA
(2) NVA
(3) NVA
(4) the regression period, 18.6 yr
(5) half the regression period, 9.3 yr

40. Which of the following is a superior planet?
(1) Jupiter
(2) Venus
(3) Earth
(4) NVA
(5) NVA

41. The configuration at which Mercury is a morning star is
(1) NVA
(2) greatest western elongation
(3) NVA
(4) greatest eastern elongation
(5) inferior conjunction

42. The term transit refers to (aside from crossing the celestial meridian, which is another meaning)
(1) a superior planet passing between the Sun and the Earth
(2) an inferior planet passing between the Sun and the Earth
(3) the Earth passing between the Sun and a superior planet
(4) NVA
(5) NVA

43. A superior planet is in retrograde motion around the time when it is at
(1) conjunction
(2) NVA
(3) NVA
(4) opposition
(5) greatest elongation

44. The interval between successive oppositions of a given superior planet is
(1) its synodic period
(2) its sidereal (orbital) period
(3) NVA
(4) NVA
(5) the sidereal year

45. The interval between successive heliacal risings of a given planet is
(1) the sidereal year
(2) NVA
(3) its synodic period
(4) its sidereal period
(5) NVA

46. The part of the Moon's shadow that is completely dark is called the
(1) NVA
(2) peninsula
(3) penumbra
(4) NVA
(5) umbra

47. Solar and lunar eclipses occur on the celestial sphere
(1) at the equinoxes
(2) along the ecliptic
(3) NVA
(4) along the celestial equator
(5) NVA

48. Solar eclipses can occur when the Moon is at which phase(s)?
(1) new only
(2) full only
(3) NVA
(4) new and full
(5) NVA

49. Which kind of eclipse is the easiest to see; that is,
is seen over the largest portion of the Earth's surface?
(1) partial solar eclipse
(2) NVA
(3) total solar eclipse
(4) NVA
(5) total lunar eclipse

50. Why are there not solar and lunar eclipses every month?
(1) the Moon's speed varies because its orbit isn't circular
(2) the Moon's orbit plane is tilted slightly with respect to the ecliptic plane
(3) NVA
(4) NVA
(5) sometimes the Moon's orbit plane doesn't cross the ecliptic plane

51. The eclipse seasons occur
(1) NVA
(2) half a year, or six months, apart
(3) every two weeks
(4) a little less than a half year apart because of the regression
(5) NVA

52. The interval between successive lunar eclipses is
(1) one synodic month
(2) NVA
(3) usually six synodic months (about 177 days) but occasionally five (148 days)
(4) NVA
(5) exactly 173 1/3 days

53. The saros is a period of time over which
(1) NVA
(2) the characteristics of eclipses repeat exactly
(3) NVA
(4) the characteristics of eclipses approximately repeat
(5) the Moon's nodes make one complete cycle

Answers: 1.(2);2.(3);3.(4);4.(1);5.(3);6.(3);7.(1);8.(1); 9.(3);10.(4);11.(1);12.(2);13.(5);
14.(2);15.(1);16.(2);17.(5); 18.(5);19.(4);20.(3);21.(2);22.(1);23.(3); 24.(2);25.(1); 26.(5);
27.(3);28.(5);29.(2);30.(1);31.(4);32.(2);33.(3); 34.(3);35.(5);36.(3);37.(5);38.(4);39.(5);
40.(1);41.(2); 42.(2);43.(4);44.(1);45.(3);46.(5);47.(2);48.(1);49.(5); 50.(2);51.(4);52.(3);53.(4).