1. The instability strip is:
a) a spiral wave pattern in a galaxy.
b) the boundary around a black hole: the point of no return.
c) the part of the H-R diagram where Cepheid variables and RR Lyrae stars lie.
d) in a binary pair, the position where the gravitational pull of the two stars is equal.
e) the upper mass limit to a white dwarf.

2. In the Milky Way, interstellar gas clouds are found:
a) Only in the halo.
b) In the bulge, disk, and halo.
c) Only in the disk.
d) Only in the bulge.
e) Only in the spiral arms.

3. What observations did Harlow Shapley make that indicated that the Sun was not the center of the Milky Way?
a) observations of the angular sizes of open clusters.
b) observations of variable stars in nearby galaxies.
c) observations of variable stars in globular clusters.
d) observations of interstellar dust clouds.
e) he counted up the number of individual stars in many directions in the sky.

4. What produces the 21 cm radio line used to map the rotation curve of the Milky Way?
a) atomic hydrogen.
b) ionized hydrogen.
c) molecular hydrogen.
d) carbon monoxide.
e) interstellar dust.

5. Compared with the Sun, most stars in the halo of the Milky Way are:
a) younger, redder, and have less heavy chemical elements.
b) younger, bluer, and have more heavy chemical elements.
c) older, redder, and have less heavy chemical elements.
d) older, bluer, and have more heavy chemical elements.
e) older, redder, and have more heavy chemical elements.

6. What is the evidence for dark matter in the Milky Way Galaxy?
a) There is much more infrared radiation coming from the Milky Way than can be accounted for by the known normal stars and interstellar clouds.
b) There is much more visible light coming from the Milky Way than can be accounted for by the known normal stars and interstellar clouds.
c) There is much more radio waves coming from the Milky Way than can be accounted for by the known normal stars and interstellar clouds.
d) The circular velocities of gas and stars in the outer part of the Milky Way are higher than can be accounted for by the known stars and interstellar clouds.
e) The circular velocities of gas and stars in the outer part of the Milky Way are less than can be accounted for by the known stars and interstellar clouds.

7. What did Robert Trumpler do to show there is interstellar dust in the Milky Way?
a) He mapped the distribution of globular clusters in the Milky Way using RR Lyrae stars. These distances were closer than expected, implying interstellar dust absorption.
b) He estimated the distance to the Andromeda galaxy using Cepheid variable stars, and found it was closer than expected, implying interstellar dust absorption.
c) He discovered the period-luminosity relationship for Cepheid variable stars. This showed that these stars are closer than expected, implying interstellar dust absorption.
d) He calculated the distances to open clusters using both brightness and angular size measurements, and found larger distances from the brightness measurements, implying interstellar dust.
e) He counted the number of stars in many position in the sky, and showed that the Sun was in the center of this distribution, indicating large amounts of interstellar dust.

8. The present estimate for the mass of the Milky Way Galaxy is:
a) 2 X 10⁸ solar masses
b) 2 X 10⁶ solar masses
c) 6 X 10¹¹ solar masses
d) 6000 solar masses
e) 2 X 10⁴ solar masses

9. Which of the following are only found in the disk and spiral arms of the Milky Way?
a) O and B stars.
b) globular clusters.
c) 0.3 solar mass main sequence stars.
d) white dwarf stars.
e) KV and MV stars.

10. Cepheid variable stars are:
a) are used to determine the distances to other galaxies.
b) are less luminous than RR Lyrae stars.
c) are main sequence O stars.
d) vary with periods of about 1-10 seconds.
e) all of the above.

11. Approximately how long does it take the Sun to orbit the Milky Way?
a) 4.6 billion years.
b) 225 million years.
c) 1 million years.
d) 1000 years.
e) 10 years.

12. How did Edwin Hubble prove that the `spiral nebulae' are galaxies like the Milky Way?
a) By observing the proper motion of the stars in the spiral arms.
b) From stellar parallax measurements.
c) By observing the light curves of Cepheid variable stars in the galaxies.
d) By measuring X-ray emission from the black holes in the centers of the galaxies.
e) By comparing photographs of the galaxies taken at different times, and observing the rotation of the galaxies.

13. In the Milky Way, globular clusters are found:
a) In the bulge, halo, and disk.
b) Only in the disk.
c) Only in the halo.
d) Only in the spiral arms.
e) Only in dense molecular clouds.

14. The Sun's location in the Milky Way is:
a) near the center.
b) in the halo.
c) in the disk, about two-thirds of the way out from the center.
d) in the bulge.
e) in a globular cluster.

15. If all the stars in the bulge of the Milky Way were replaced by a black hole with the same mass, then:
a) The Sun would be drawn into this black hole.
b) The velocity at which the Sun orbits the Galactic Center would decrease.
c) The velocity at which the Sun orbits the Galactic Center would increase.
d) The velocity at which the Sun orbits the Galactic Center would stay the same.
e) The Sun would fly off in a straight line into intergalactic space.

16. In the Milky Way, HII regions are found:
a) Only in the halo.
b) In the bulge, disk, and halo.
c) Only in the disk.
d) Only in the bulge.
e) In the bulge and disk, but not in the halo.

17. What astronomical accomplishment is Henrietta Leavitt best remembered for?
a) She mapped the distribution of globular clusters in the Milky Way using RR Lyrae stars, and showed that the Sun was NOT in the center of the Milky Way.
b) She estimated the distance to the Andromeda galaxy using Cepheid variable stars, and found it was OUTSIDE the Milky Way.
c) She discovered the period-luminosity relationship for Cepheid variable stars.
d) She was the first person to look at the Milky Way with a telescope, and showed that it is made up of many stars.
e) She discovered the four biggest moons of Jupiter.

18. Approximately how many times has the Sun orbited the Milky Way?
a) a billion times.
b) a million times.
c) 20 times.
d) 1 time.
e) it has never orbited the Milky Way; during the entire life of the Sun, it has only moved a tiny fraction of the full circumference of the Milky Way.

19. An RR Lyrae star is:
a) An eclipsing binary star.
b) A white dwarf in a mass-transfer binary system.
c) A neutron star in a mass-transfer binary system.
d) A variable star which can be used for distance determination.
e) A post-AGB star.

20. Which of the following is a typical characteristic of an elliptical galaxy?
a) contains many main sequence O and B stars.
b) contains large quantities of interstellar matter.
c) has bulge and a flattened disk.
d) has spiral arms in its disk.
e) is a flattened sphere of mostly older stars.

21. The Hubble Tuning Fork diagram is:
a) a plot of velocity vs. distance.
b) a diagram showing the different types of galaxies, in order from ellipticals to irregulars.
c) a map of the Milky Way.
d) a plot of velocity vs. Right Ascension.
e) a `slice of the Universe' plot.

22. What is the difference between an Sa galaxy and an Sc galaxy?
a) Sa galaxies have larger bulges, and more tightly wrapped spiral arms.
b) Sa galaxies have smaller bulges, and more loosely wrapped spiral arms.
c) Sa galaxies have smaller bulges, and more tightly wrapped spiral arms.
d) Sa galaxies have bars, while Sc galaxies do not.
e) Sa galaxies do not have disks or spiral arms, while Sc galaxies do.

23. Compared to an E7 galaxy, an E0 galaxy:
a) has a more round appearance on the sky.
b) has a flatter appearance on the sky.
c) has more tightly wrapped spiral arms.
d) has more loosely wrapped spiral arms.
e) has a larger disk, relative to the size of its bulge.

24. A pulsar is:
a) An eclipsing binary star.
b) a rapidly rotating white dwarf emitting a beam of light that passes across the Earth.
c) a rapidly rotating neutron star emitting a beam of light that passes across the Earth.
d) a giant star that is pulsating in and out with time.
e) a planet that is periodically eclipsing a star.

25. A Type I supernova occurs when:
a) a massive star at the end of its life explodes as a supernova.
b) two neutron stars merge to form a black hole.
c) a low mass star nears the end of its life, and sheds its outer layers.
d) gas from a companion star accretes onto a white dwarf, and the total mass is greater than 1.4 solar masses.
e) a main sequence O star excites surrounding interstellar gas.

26. What object was nicknamed "L.G.M." by astronomers?
a) Cygnus X-1.
b) Sagittarius A*.
c) SN 1987A.
d) The first white dwarf discovered.
e) The first neutron star discovered.

27. A nova is:
a) a brand new star, very recently formed.
b) a giant star in its pulsating stage, before it sheds its outer layers and becomes a planetary nebula.
c) a massive star that explodes after its core becomes iron.
d) a flare-up of nuclear reactions on the surface of a white dwarf, caused by accretion of gas from a companion.
e) regular pulses of light from a neutron star.

28. A pulsar:
a) does not spin on its axis.
b) is spinning at a very slow rate (once every 1000 years).
c) spins on its axis 1-10 times per year.
d) spins on its axis 1-1000 times per second.
e) spins on its axis 100 billion times per second.

29. The eclipsing binary star Algol (`The Ghoul') contains a massive main sequence star and a lower mass giant star. The lower mass star has left the main sequence, but the higher mass star is still a main sequence star. Which of the following statements is correct?
a) the lower mass star probably formed much earlier than the other star, which is why it is in a later evolutionary stage.
b) the lower mass star probably formed much later than the other star, but it ran out of hydrogen in its core first because it had such a low mass.
c) the two stars formed at the same time, but higher mass stars have longer main sequence lifetimes, so the high mass star has not yet left the main sequence.
d) the lower mass star probably exploded as a supernova, so lost a lot of mass.
e) the star that is now higher mass probably initially had a lower mass, but gained mass from its companion.

30. Supernova 1987A showed strong hydrogen lines in its spectrum. Therefore:
a) it was initially a white dwarf that exceeded the Chandrasekhar limit.
b) it was a massive star that just finished burning hydrogen to helium in its core.
c) when it exploded, its core was made up mainly of carbon.
d) it was a massive star with an iron core that collapsed beyond the electron degeneracy limit.
e) it was a white dwarf turning into a neutron star.

31. Which of the following statements about supernovae is correct?
a) on average in the Milky Way, supernovae occur approximately once every 200 years.
b) the majority of stars in the Milky Way will eventually blow up as a supernova.
c) new supernova are seen in the Milky Way almost every year.
d) the same star will turn into a supernova over and over again.
e) a Supernova Type II is caused by nuclear reactions flaring up on the surface of a white dwarf.

32. A supernova with strong hydrogen lines in its spectrum is caused by:
a) a flare-up of nuclear reactions on the surface of a white dwarf in a mass transfer binary.
b) a flare-up of nuclear reactions on the surface of a neutron star in a mass transfer binary.
c) the accretion of matter onto a white dwarf, causing the white dwarf to go over the Chandrasekhar limit.
d) the explosion of a massive star with an iron core.
e) the merger of two neutron stars into a black hole.

33. A pulsar:
a. is mainly made of hydrogen (75 percent by mass).
b. is mainly carbon, with a bit of helium and oxygen.
c. has a core of iron, surrounded by layers with increasingly lighter atoms.
d. is a dense ball of neutrons.
e. is a singularity, surrounded by an accretion disk.

34. The first neutron star discovered was nicknamed:
a) the N.S.
b) SN 1987A.
c) L.G.M.
d) M.L.G.
e) Bell's star.

35. Which of the following events can reoccur, with the same star?
a) a nova.
b) a supernova type I.
c) a supernova type II.
d) all of the above.
e) none of the above.

36. Which of the following statements are correct?
a) All pulsars are neutron stars.
b) All neutron stars are seen as pulsars from Earth.
c) All pulsars are white dwarfs.
d) All pulsars are white dwarfs in mass transfer binary systems.
e) All pulsars are rapidly-spinning protostars.

37. What causes the very regular radio `blips' from a pulsar?
a) the star is pulsating in size.
b) as the pulsar spins, a beam of light regularly sweeps across the Earth.
c) a companion is dumping gas onto the pulsar, causing bursts of nuclear fusion.
d) a companion is periodically eclipsing the pulsar.
e) an extraterrestrial civilization.

38. A nova is:
a) A massive star that exploded.
b) A white dwarf in a mass transfer binary that exploded.
c) A flare-up of nuclear reactions on the surface of a white dwarf in a mass transfer binary.
d) A flare-up of nuclear reactions on the surface of a neutron star in a mass transfer binary.
e) A flare-up of nuclear reactions in an accretion disk around a black hole in a mass transfer binary.

39. Jupiter has a mass about 300 times the mass of the Earth. If Jupiter turned into a black hole with the same mass, but nothing else changed,
a) its moon Europa would be pulled into the black hole.
b) its moon would orbit around Jupiter at a distance equal to the Schwarzchild radius of the black hole.
c) Europa would continue in its same orbit.
d) the entire solar system would be pulled into this black hole.
e) the Schwarzchild radius of this black hole would be about 3000 km.

40. The "point of no return" around a black hole, inside which one cannot escape from, is called the:
a) The Chandrasekhar limit.
b) The Lagrange point.
c) The gravitational lens.
d) The event horizon.
e) The Pauli Exclusion limit.

41. Imagine you are in a rocketship, about 10 Schwarzchild radii away from a black hole. Which of the following would you NEVER observe?
a) X-ray radiation coming out from within the Schwarzchild radius of the black hole.
b) A shift in the apparent position of nearby stars, due to the gravitational effect of the black hole.
c) Very strong tidal forces from the black hole.
d) A shift in the wavelength of light from stars in the direction opposite that of the black hole.
e) Your clocks will run slower than clocks back home on Earth.

42. Which of the following has the smallest radius?
a) a 1 solar mass white dwarf.
b) a 2 solar mass neutron star.
c) a 1 solar mass black hole.
d) a 100 solar mass black hole.
e) a million solar mass black hole.

43. The Schwarzchild radius of a black hole is:
a) The radius of the singularity.
b) The distance between the black hole and its associated white hole.
c) The radius of the event horizon.
d) The distance from the black hole where the gravitational field from the black hole is zero.
e) The distance from the black hole at which you would be pulled apart by tidal forces.

44. Harlow Shapley:
a) Provided the first conclusive evidence that `spiral nebulae' are outside the Milky Way.
b) Identified the emission lines from quasars.
c) Discovered the Period-Luminosity relation for Cepheid variables.
d) Measured the distances to globular clusters, and concluded the Sun was NOT in the center of the Milky Way.
e) Made a 3-dimensional map of the Milky Way by counted stars and estimating brightnesses, and concluded that the Sun WAS in the center of the Milky Way.

45. Edwin Hubble:
a) Provided the first conclusive evidence that `spiral nebulae' are outside the Milky Way.
b) Identified the emission lines from quasars.
c) Discovered the Period-Luminosity relation for Cepheid variables.
d) Measured the distances to globular clusters, and concluded the Sun was NOT in the center of the Milky Way.
e) Made a 3-dimensional map of the Milky Way by counted stars and estimating brightnesses, and concluded that the Sun WAS in the center of the Milky Way.

46. Henrietta Leavitt:
a) Provided the first conclusive evidence that `spiral nebulae' are outside the Milky Way.
b) Identified the emission lines from quasars.
c) Discovered the Period-Luminosity relation for Cepheid variables.
d) Measured the distances to globular clusters, and concluded the Sun was NOT in the center of the Milky Way.
e) Made a 3-dimensional map of the Milky Way by counted stars and estimating brightnesses, and concluded that the Sun WAS in the center of the Milky Way.

47. The diameter of the disk of the Milky Way is approximately:
a) 300 A.U.
b) 10 light years.
c) 100 thousand light years.
d) a billion light years.
e) a billion billion light years.

48. Where in the Milky Way are Type II supernovae usually found?
a) only in the disk.
b) only in the halo.
c) only at the very center.
d) only in the bulge.
e) in the disk, halo, and bulge.

49. The main difference between an Sc galaxy and an Sa galaxy is:
a) the Sa galaxy has a bar; the Sc galaxy does not.
b) the Sa galaxy has a larger bulge and more tightly wrapped spiral arms.
c) the Sa galaxy is an elliptical; the Sc galaxy is a spiral.
d) the Sa galaxy is an irregular galaxy; the Sc galaxy is a spiral.
e) The Sc galaxy has a larger bulge and more tightly wrapped spiral arms.

50. From the orbital velocity of the Sun around the Milky Way, 220 km/s, and the distance from the Sun to the center of the Galaxy, using the relationship V² = GM/R, one can calculate a mass. This is the mass of:
a) the Sun.
b) Sgr A*.
c) the entire Milky Way.
d) the part of the Milky Way that is outside of the Sun's orbit.
e) the part of the Milky Way galaxy that is inside of the Sun's orbit.

51. The Milky Way is:
a) a globular cluster.
b) an elliptical galaxy.
c) an irregular galaxy.
d) we do not know if it is an elliptical or a spiral.
e) a spiral or barred spiral galaxy.

52. Synchrotron radiation is produced by:
a) a hot solid object, like the filament in a light bulb.
b) electrons in atoms jumping from lower energy levels to higher energy levels.
c) electrons in atoms jumping from higher energy levels to lower energy levels.
d) nuclear fusion only.
e) accelerated charged particles.

53. The four types of stars listed below have very different densities. The correct order, from lowest to highest density, is:
a) M3III, G2V, white dwarf, neutron star.
b) G2V, M3III, white dwarf, neutron star.
c) M3III, G2V, neutron star, white dwarf.
d) white dwarf, M3III, G2V, neutron star.
e) neutron star, white dwarf, M3III, G2.

54. What is a neutron star?
a) an object with a mass of about 1 solar mass and a diameter about the same as that of the Earth.
b) an object with a mass between 1.4 and 3 solar masses and a diameter of about 20 km.
c) a ball of gas that has never had on-going nuclear reactions.
d) a ball of carbon and/or helium and/or oxygen and/or neon held up against gravity by electron degeneracy pressure.
e) an object so dense that nothing, not even light, can escape its gravitational field.

55. A pulsar is:
a) An eclipsing binary star.
b) a white dwarf.
c) a neutron star.
d) a giant star that is pulsating in and out with time.
e) a planet that is periodically eclipsing a star.

56. What type of star may eventually evolve into a neutron star?
a) a brown dwarf.
b) an O9V star.
c) a G2V star.
d) a white dwarf.
e) a K3V star.

57. What is the upper limit to the mass of a neutron star?
a) 0.08 solar masses.
b) 1 solar mass.
c) 1.4 solar masses.
d) 3 solar masses.
e) there is no known upper limit.

58. The four objects listed below have very different densities. The correct order, from lowest to highest density, is:
a) The Sun, Sirius B, the pulsar in the center of the Crab Nebula, Betelgeuse.
b) Betelgeuse, the Sun, Sirius B, the pulsar in the center of the Crab Nebula.
c) Sirius B, Betelgeuse, the Sun, the pulsar in the center of the Crab Nebula.
d) the pulsar in the center of the Crab Nebula, Sirius B, the Sun, Betelgeuse.
e) Betelgeuse, the Sun, the pulsar in the center of the Crab Nebula, Sirius B.

59. Which of the following is closest in diameter to a neutron star?
a) the orbit of the Earth around the Sun.
b) the Sun.
c) the Earth.
d) Johnson City.
e) the head of a pin.

60. In which of the following does electron degeneracy pressure hold the core up against gravity?
a) a white dwarf star.
b) a high mass main sequence star.
c) a neutron star.
d) a one solar mass main sequence star.
e) a horizontal branch star.

61. Who discovered the period-luminosity relationship for Cepheid variable stars?
a) Harlow Shapley.
b) Edwin Hubble.
c) Adriaan van Maanen.
d) William Herschel.
e) Henrietta Leavitt.

62. Who first measured the distances to globular clusters, and concluded that the Sun was NOT in the center of the Milky Way?
a) Harlow Shapley.
b) Edwin Hubble.
c) Adriaan van Manaan.
d) William Herschel.
e) Henrietta Leavitt.

63. What was the first evidence that the so-called `spiral nebulae' were OUTSIDE of the Milky Way?
a) Their rotation in the plane of the sky was measured, which gave an estimate of their distance.
b) Their proper motion was measured, which gave an estimate of their distance.
c) Their stellar parallax was measured, which gave an estimate of their distance.
d) Spectroscopic parallax was used, which gave a measure of their distance.
e) The periods of Cepheid variables in these `nebulae' were measured, and used to get their luminosities.

64. Which of the following objects are NOT generally found in the bulge of the Milky Way, but only in the disk?
a) planetary nebulae.
b) open clusters.
c) white dwarfs.
d) Supernovae Type I.
e) globular clusters.

65. Sagittarius A* is:
a) the brightest supernovae seen in the last 300 years.
b) a small irregular galaxy in orbit around the Milky Way.
c) a 10 solar mass black hole in a mass-transfer binary system with a giant star.
d) a 2 million solar mass black hole in the center of the Milky Way.
e) the first pulsar ever discovered.

66. A flare-up of nuclear reactions on the surface of a white dwarf, due to mass transfer from a companion, is called a:
a) Nova.
b) Supernova Type I.
c) Supernova Type II.
d) X-Ray Burster.
e) RR Lyrae star.

67. A black hole is:
a) the end stage of stellar evolution for an isolated 1 solar mass star.
b) produced during a nova.
c) produced by an explosion of a white dwarf in a mass transfer system.
d) a really massive object (greater than 10⁶ solar masses).
e) an object with an escape velocity greater than the speed of light.

68. When a charged particle is accelerated, it produces light. This kind of light is called:
a) Heat radiation.
b) Thermal radiation.
c) Synchrotron radiation.
d) Magnetic radiation.
e) RR radiation.

69. A spiral galaxy with a central bar, a large bulge, and tightly wrapped spiral arms is classified as a/an:
a) Sbc galaxy.
b) SBc galaxy.
c) SBa galaxy.
d) Eb galaxy.
e) EBa galaxy.

70. The Large Magellanic Cloud is a/an:
a) Sa galaxy.
b) Elliptical galaxy.
c) Sb galaxy.
d) SBb galaxy.
e) Irregular galaxy.

71. What provided the first evidence of the existence of large quantities of dark matter in the Universe?
a) The light curves of galaxies.
b) The rotation curves of galaxies.
c) Mapping the distribution of globular clusters in the Milky Way.
d) The discovery of the period-luminosity relationship for Cepheids.
e) The discovery of pulsars.

72. The Tuning Fork Diagram is:
a) a description of the period-luminosity relationship for Cepheid variable stars.
b) a plot showing the location of the instability strip on the HR diagram.
c) a diagram showing the different types of galaxies.
d) a diagram showing the structure of a black hole.
e) a plot of energy vs. mass for supernovae.

73. Compared to an E7 galaxy, an E0 galaxy has:
a) a smaller bulge and more tightly wrapped spiral arms.
b) a smaller bulge and less tightly wrapped spiral arms.
c) a much more irregular structure, with many HII regions.
d) a rounder appearance on the sky.
e) a flatter appearance on the sky.

74. An RR Lyrae star is:
a) a white dwarf star undergoing mass transfer from a companion.
b) a neutron star undergoing mass transfer from a companion.
c) a star that lies above the main sequence on an HR diagram, in the instability strip.
d) a white dwarf that has cooled to become very dim.
e) a neutron star with a beam of light that regularly sweeps across the Earth.

75. The radius of the event horizon of a black hole is called the:
a) Shapley radius.
b) Synchrotron radius.
c) Pauli radius.
d) Schwarzchild radius.
e) Wormhole radius.

76. What phenomenon was observed during the 1919 total solar eclipse?
a) The positions of stars behind the Sun appeared shifted.
b) The velocity of the light from stars near the Sun appeared faster than normal.
c) The velocity of the light from stars near the Sun appeared slower than normal.
d) Light from the Sun was observed to be gravitationally blueshifted.
e) All of the above.

77. How far is the Sun from the center of the Milky Way?
a) 8.5 light years.
b) 8.5 parsecs.
c) 8.5 kiloparsecs.
d) 8.5 A.U.
e) the Sun is at the center of the Milky Way.

78. Robert Trumpler found that for open clusters, distances determined from their brightnesses (assuming a constant luminosity) are larger than those determined from their angular sizes (assuming a constant physical size). This is considered evidence for the existence of:
a) Many unseen black dwarfs.
b) Interstellar dust.
c) Black holes.
d) Exotic subatomic particles contributing substantially to the mass of the Galaxy.
e) All of the above.

79. Who made the first map of the Milky Way by using his telescope to count the stars towards many directions in the sky?
a) Harlow Shapley.
b) Edwin Hubble.
c) Adriaan van Maanen.
d) William Herschel.
e) Henrietta Leavitt.

80. The angular rotation of spiral galaxies in the plane of the sky is measured by:
a) stellar parallax.
b) the Doppler shift.
c) spectroscopic parallax.
d) Cepheid variations.
e) it is not possible to measure the rotation of galaxies in the plane of the sky; this shift is too small to measure.

81. On the H-R diagram, Cepheids variables lie:
a) below and to the left of the main sequence.
b) below and to the right of the main sequence.
c) on the far right above the main sequence, in the MIII star region.
d) on the main sequence, in the upper left of the diagram.
e) above the main sequence in the instability strip.

82. Most of the following objects are mainly found in the plane of the disk of the Milky Way, but usually not in the bulge or the halo. Which is the exception, being commonly found in the bulge and halo as well as the disk?
a) HII regions.
b) Molecular clouds.
c) Open clusters.
d) Globular clusters.
e) O and B stars.

83. The first person to find evidence that the Sun is not in the center of the Milky Way was:
a) Henrietta Leavitt.
b) Harlow Shapley.
c) Edwin Hubble.
d) William Herschel.
e) Robert Trumpler.

84. Rotation curves of galaxies are plots of:
a) Orbital period vs. Hubble type.
b) Number of stars vs. distance from center.
c) Circular orbital velocity vs. distance from center.
d) Hubble type vs. roundness of shape.
e) Hubble type vs. circular orbital velocity.

85. The massive black hole in the center of our galaxy is called:
a) Cygnus X-1.
b) The Schwarzchild object.
c) L.G.M.
d) RR Lyrae.
e) Sagittarius A*.

Answers: 1c, 2c, 3c, 4a, 5c, 6d, 7d, 8c, 9a, 10a, 11b, 12c, 13a, 14c, 15d, 16c, 17c, 18c, 19d, 20e, 21b, 22a, 23a, 24c, 25d, 26e, 27d, 28d, 29e, 30d, 31a, 32d, 33d, 34c, 35a, 36a, 37b, 38c, 39c, 40d, 41a, 42c, 43c, 44d, 45a, 46c, 47c, 48a, 49b, 50e, 51e, 52e, 53a, 54b, 55c, 56b, 57d, 58b, 59d, 60a, 61e, 62a, 63e, 64b, 65d, 66a, 67e, 68c, 69c, 70e, 71b, 72c, 73d, 74c, 75d, 76a, 77c, 78b, 79d, 80e, 81e, 82d, 83b, 84c, 85e.