Review Questions

Sample Questions

1. If the size of the box of the lyre of the constellation Lyra is 5 degrees on a side, how many full moons would fit along the side? How many Suns?

2. How many arcseconds make up 360 degrees?

3. If you hold your arm out and make a fist, how many degrees of the sky does it blot out.

4. (T/F) The Dipper is just another name for the constellation Ursa Major.

5. In what constellation is the star Vega? Polaris? Deneb?

6. Which is brighter, a first magnitude star or a third magnitude star?

7. One star appears 10,000 times brighter than another. What is the difference in magnitudes between these two stars?

8. (T/F) Gamma rays have a longer wavelength than X-rays.

9. Name three wavebands which cannot pass through the Earth's atmosphere to reach the ground.

10. What does the prefix "nano-" mean?

11. Sketch the optical layout of our Meade Schmidt-Cassegrain telescopes.

12. For a given telescope, the longer the focal length of the eyepiece, the (smaller,larger) the magnification and the (smaller,larger) the field of view.

13. What is the effective focal length of a telescope with a 4 meter mirror if you observe at the f/8 Cassegrain focus. What focal length eyepiece is needed to yield a magnification of x100.

14. If the faintest stars you can see with an 8 inch telescope are magnitude 14, what is the magnituce of the faintest stars you can see with a 16 inch telescope.

15. (T/F) The zodiac is the group of constellations located within about 9 degrees of the celestial equator.

16. (T/F) The point directly overhead is called the north celestial pole.

17. Briefly state what the following are : Meridian; Zenith; Horizon Plane; Transit; Synodic vs Sidereal period.

18. At what latitude does the noon sun pass directly overhead at mid-summer. What is the special name for this latitude.

19. At about what time of night would you expect to see the constellation Sagittarius rise over the Eastern horizon on May 15?

20. Which of the following is a circumpolar constellation? a) Aquila; b) Delphinus; c) Cassiopeia; d) Canis Major; e) Aries.

21. From what location on the Earth are all parts of the celestial sphere visible for at least some time during the year ?

22. What is the sun's location on 21 March and in which direction is it moving with respect to the celestial equator.

23. On what day of the year is the declination of the sun the largest? What is its value on that day?

24. Answer the following questions using the fact that Charlottesville is at a latitude of +38 degrees. (You should draw a sketch to remind yourself of the relationship between the various quantities involved.)

  1. What is the altitude of the north pole above the northern horizon?
  2. What is the altitude of the celestial equator at the meridian above the Sourhern horizon ?
  3. What is the altitude above the southern horizon of an object with a declination of -38 degrees when it is on the meridian ?

25. If the siderial time is 20 hours, will an object with a Right Ascension of 16 hours be found east or west of the meridian ?

26. What is the sidereal time on July 21 at 10pm? Could you see a galaxy with coordinates RA=4h 20m Dec=+40 at that time ?

27. When does third quarter moon rise ?

28. How many degrees separate the sun and moon when the moon's phase is waxing crescent, 3 days past new moon.

29. Describe what precession of the earth's rotation axis is and why it occurs. How does precession affect : the location of the NCP in the sky; the location of the vernal equinox in the sky; the month in which spring occurs; the astrological sign of someone who is born at the end of March.

30. What is the interval of time for a full precession cycle.

31. How many degrees around the equator does the vernal equinox move in a century.

32. (T/F) In precession, the sun and moon slowly pull the earth's equatorial bulge into alignment with the ecliptic.

33. (T/F) Orion will always be a winter constellation.

34. What kind of eclipse does someone in the penumbral shadow of the moon see ?

35. Eclipses can only occur :

  1. at new moon;
  2. at full moon;
  3. at new or full moon
  4. at either quarter moon.

36. Why is the moon still visible during a total lunar eclipse ?

37. What is the inclination of the moon's orbit relative to the ecliptic; what are the nodes of the moon's orbit; Why must the moon be at a node for an eclipse to occur?

38. (T/F) The moon's line of nodes precesses once every 26,000 years.

39. (T/F) Eclipses occur, typically, about every four months.

40. Roughly how often does Mars pass throught the constellation of Orion?

41. (T/F) Neither venus nor mercury can reach quadrature.

42. An inferior planet has a greatest elongation of 33 degrees. What is its distance to the sun in AU?

43. (T/F) Mars shows a half phase at Quadrature.

44. You are on Mars. It is martian midnight. You see a planet high in the sky. Which of the following planets could that planet be?

  1. Earth
  2. Saturn
  3. Venus
  4. Any of the above

45. (T/F) Venus orbits the sun in about 7 months. If Venus is at greatest eastern elongation in January, then the next time it will be at greatest eastern elongation will be in July.

46. In general, Uranus undergoes retrograde motion twice as often as Neptune.

47. Jupiter is about to reach opposition. Which direction in the sky is it moving ?

48. Why is Saturn so oblate ?

49. (T/F) Blue stars are cooler than green ones.

50. Which of the following properties requires knowing the distance to the star in order to determine that property's value? (a) luminosity, (b) temperature, (c) apparent magnitude, (d) composition

51. A star is at a distance of 5 pc. What is the observed parallax angle?

52. The main sequence represents stars in the H--R diagram that (a) have just finished nuclear burning at the center, (b) are very young stars, (c) are very old stars, (d) have not yet depleted their central hydrogen supply.

53. The axes on an HR diagram are: (a) stellar diameter versus spectral type. (b) wavelength versus frequency. (c) luminosity versus spectral type. (d) intensity of radiation versus wavelength.

54. Nuclear reactions which power the Sun convert (a) a helium nucleus into hydrogen nuclei (b) four hydrogen nuclei into one helium (c) a hydrogen nucleus into a helium nucleus (d) deuterium into hydrogen

55. When the Sun ultimately dies in another 5 billion years it will (a) become a black hole and an X--ray source (b) become a neutron star and a pulsar (c) become a white dwarf with a planetary nebula (d) completely disappear in a supernova explosion

56. The core of a supermassive star is composed of which element if it is about to create a supernova? (a) iron (b) helium (c) neon and magnesium (d) carbon

Answers can be found here but dont look at them until you have made your own efforts !