ASTR final assignment

  1. Of the following types of radiation, which has the smallest (i.e., the least energetic) photons or quanta?
    Radio waves
  2. Sunspots are associated with distortions in the Sun’s
    magnetic field
  3. Of the many complex molecules found in interstellar space, most are based on which element?
  4. What is a common use for an interferometer in observational astronomy?
    To improve the angular resolution of radio telescopes
  5. When the Moon is at third quarter, what time will it rise?
  6. **The “helium flash” occurs at what stage in stellar evolution?
    Red giant
  7. What two observations of an object allow for a determination of the Milky Way's mass?
    An object's velocity and distance from the galactic center
  8. The Sun rotates once in approximately one
  9. The so-called “cosmological principle” is simply the idea that the basic large-scale features of the universe
    are the same regardless of location
  10. Ultraviolet radiation is of ________ than red light.
    higher frequency and shorter wavelength
  11. Quasars have their distances measured by what technique?
    Hubble Law
  12. **Which of the following are not intrinsic variable stars?
    Eclipsing variables
  13. What would Jupiter have needed to have become a star?
    More mass
  14. The time required for a photon to travel across our galaxy is about _____ years.
    • 160,000 years
    • (the middle one)
  15. Suppose that in the spectrum of a star the spectral lines are observed to be alternately single and then double in a periodic fashion. The star is probably
    a spectroscopic binary.
  16. Beyond 100 parsecs, the distances determined by the method of trigonometric parallaxes become very unreliable because
    the parallax angles become too small to measure accurately.
  17. The Ptolemaic system accounts for retrograde motion by
    having the planets travel on epicycles.
  18. **The constellations that are visible in the early evening gradually change throughout one year due to the
    revolution of the Earth about the Sun
  19. An often-observed meteor shower, like the Leonids
    is visible on approximately the same date each year.
  20. The Pleiades cluster of stars is an excellent example of a
    galactic or open cluster.
  21. A galaxy is at a distance of one billion light years. Which of the following is true?
    We see the galaxy the way it was one billion years ago.
  22. In the Drake equation, a technological civilization is considered to be
    a civilization that can communicate over interstellar distances.
  23. All of the following may be used to estimate the solar surface temperature except
    Kepler's laws.
  24. Why does a star of type G5 have many absorption lines in its spectrum due to metallic elements such as iron, silicon, titanium, etc., while a star of type B5 shows very few lines of such elements?
    The B star is very hot and nearly all of its metallic atoms are ionized, which makes them incapable of absorbing photons having visible wavelengths.
  25. Galileo discovered all of the following except
    the planet Uranus.
  26. **The differences in stellar spectra are due primarily to differences in
  27. A star that is responsible for causing a nebula to fluoresce (i.e., emit an emission spectrum) is most likely a star of type
    O or B (cause they're hot)
  28. The gravitational attraction between two bodies depends on the distance, r, between them. The attraction varies with the distance as
    1/r2. (the most complex one)
  29. **The North Star does not appear to move during the night because
    it lies approximately over the northern axis of the Earth.
  30. The type of intrinsic variable stars often found in globular clusters are known as ________ stars.
    RR Lyrae
  31. The ancients thought that rest (i.e., no motion) was the natural state for a material body. Newton's ________ law states that uniform linear motion is just as natural as rest.
  32. **What do we learn from the Doppler shift when we observe the spectrum of a star?
    The star's radial velocity
  33. In general, the tail of a comet streams away from the comet in a direction
    away from the Sun.
  34. A star with a spectral type of B2V would be referred to as which of the following?
    Upper main sequence
  35. The absolute magnitude of the Sun is about
  36. **If an object is moving toward you, what effect do you observe in the spectrum of that object?
    It appears blue-shifted.
  37. The observed slowing of a clock in the vicinity of a black hole is a prediction of
    general relativity.
  38. **On March 21, the right ascension of the Sun is about
    0 hours.
  39. **All stars of spectral type G2 have approximately the same
  40. Which type of galaxy has a stellar disk, but without gas or dust?
  41. Which of the following are not found in the galaxy's spiral arms?
    Globular clusters
  42. Pair production can occur if
    the energy of two photons is greater than the combined mass-energy of a particle-antiparticle pair.
  43. Would the Moon be a good place to do astronomy?
    Yes, because it lacks an atmosphere.
  44. Cepheid variable stars are useful as distance indicators because they show a definite, simple correlation between their period of light variation and their
    average absolute magnitude.
  45. The law of universal gravitation was developed by
  46. One wavelength that may provide contact with extraterrestrial civilizations is found at
    21 cm
  47. “Conservation of angular momentum” means that a spinning body tends to
    keep spinning.
  48. Boston is 90° east of Hawaii. If it is noon in Hawaii, in Boston it would be about
  49. What do all kinds of electromagnetic (i.e., radiant) energy have in common?
    All have the same speed in a vacuum.
  50. A star that shows evidence of molecules in its spectrum would be considered
    very cool.
  51. All eclipsing binaries are also
    spectroscopic binaries.
  52. Ten parsecs is the standard distance that has been selected as the basis for defining the astronomical scale of
    absolute magnitudes
  53. How to find magnification from focal lengths
    Lens (in inches)/eyepiece
  54. How do the escape velocities of the Jovian planets compare to those of the terrestrial planets?
    The Jovian planets have much higher escape velocities.
Card Set
ASTR final assignment