Part I: Multiple Choice Questions. There are 30 multiple choice questions worth 2 points each. Choose the best answer and record it on the scan sheet. 1. Most of the stars in our galaxy (about 90%) are now on the main sequence in the HR diagram. That is because A. red giants only form from the relatively rare highly massive stars. B. it is the only stable configuration for a star. C. there are no old stars in our galaxy. D. it is the longest lived phase of life for most stars. 2. Which statement below concerning the Jovian planets is INCORRECT? A. The Jovian planets have more satellites than the terrestrial planets. B. All the Jovian planets have rings encircling them. C. The Jovian planets are composed primarily of hydrogen and helium. D. The Jovian planets have shorter orbital periods than terrestrial planets. 3. Main sequence stars obey a relation between A. none of these. B. age and spectral type. C. mass and luminosity. D. composition and surface temperature. 4. The composition of solid objects in the outer solar system differs from those inside the frost line in that A. they are composed of ices as well as rocks and metals. B. they are composed of rock. C. they are composed of ices instead of rock. D. there is no difference. 5. Which of the following types of observations must be done above the Earth's atmosphere? A. Optical B. All of these can be done on the earth. C. Radio D. X-ray 6. The main sequence is primarily a sequence in stellar A. age. B. size. C. mass. D. composition. 7. Stars twinkle more than planets because A. of an optical illusion that makes all dim light sources flicker. B. the light output from stars are intrinsically more variable than from planets. C. refraction of light by irregularities in our atmosphere affects small sources more than large ones. D. starlight scatters differently from atmospheric dust particles than light from planets. 8. Wien's law relates A. the color of radiation to the temperature of the body emitting it. B. the wavelength of light to its velocity. C. the shape of an orbit to its distance from the Sun. D. an object's speed to its mass. 9. Close up images of asteroids obtained by space probes show that asteroids have A. cratered surfaces. B. spherical shapes. C. atmospheres. D. volcanic activity. 10. Electromagnetic radiation can be described A. only as a particle. B. only as what our eyes can see. C. only as a wave. D. both as a wave and as a particle. 11. If all the asteroids in the asteroid belt were assembled into a planet, it would have a mass A. About the same mass as the Earth. B. Much greater than Jupiter's mass. C. Much less than that of the Earth. D. About the same mass as Jupiter. 12. Fusion reactions can occur in A. Jupiter mass exoplanets. B. test tube mixtures of palladium and heavy water. C. brown dwarfs. D. stars with masses exceeding 8% of the sun's mass. 13. Which of the following is NOT one of Kirchoff's Laws? A. A cool medium obscuring a continuum source results in an absorption line spectrum. B. Hot, diffuse gas produces an emission line spectrum. C. Hot, dense objects emit a continuous spectrum. D. The peak wavelength of light emitted by a thermal source decreases with increasing temperature. 14. The Hertzsprung-Russell (H-R) diagram is a plot of stellar A. temperature vs. mass. B. mass vs. age. C. spectral type vs. color. D. luminosity vs. temperature. 15. As a star like the Sun evolves into a red giant, its core A. expands and heats. B. expands and cools. C. contracts and cools. D. contracts and heats. 16. What is a star's source of energy during its main-sequence phase? A. Hydrogen fusion B. Gravitational contraction C. Uranium fission D. Convection 17. Which of the following main-sequence stars would have the highest surface temperature? A. A0 B. B5 C. M1 D. G2 18. What is the energy source of brown dwarfs? A. Hydrogen fusion B. Uranium fission C. Convection D. Gravitational contraction 19. In order to begin nuclear fusion, a high temperature is required in the center of a star to overcome the A. electrical repulsion between protons. B. nuclear force between protons. C. nuclear force between neutrons. D. gravitational force between particles. 20. The Hubble Space Telescope (HST) is more powerful than ground-based telescopes for many astronomical studies because A. it has a larger mirror than any ground-based telescope B. it can go close to the stars C. it uses electronic detectors, not photographic film D. its images are not blurred by the earth's atmosphere 21. As the solar nebula collapsed, A. it gradually flattened to a disk-shaped cloud. B. the amount of angular momentum remained the same. C. all of the other answers. D. the bulk of the gas ended up in the Sun. 22. Comets differ from asteroids in that A. they have low densities. B. they are composed of ice as well as rock. C. they do not have cratered surfaces. D. there are not many of them. 23. In order from the hottest to the coolest stars, the order of the stellar spectral sequence is A. OBAFGKM B. ABFGKMO C. MKGFABO D. OBFGAMK 24. Globular clusters are A. diffuse stellar systems held together by unseen dark matter. B. dark patches ("globules") of dust in interstellar space. C. gravitationally bound aggregates of millions of stars. D. loose associations of young stars. 25. The map of solar system in order of distance from the sun would read A. terrestrial planets, asteroid belt, jovian planets, Kuiper belt. B. terrestrial planets, jovian planets, asteroid belt, Kuiper belt. C. jovian planets, asteroid belt, terrestrial planets, Kuiper belt. D. terrestrial planets, asteroid belt, Kuiper belt, jovian planets. 26. The two main reasons we use large telescopes for observations in astronomy are: A. Light gathering power and resolution. B. Magnification and resolution. C. Magnification and clarity. D. Magnfication and optical quality. 27. What is the primary energy transport mechanism in stars? A. Convection. B. Radiation. C. A combination of radiation and convection. D. A combination of convection and conduction. 28. The mass of a main-sequence star determines all of the following properties EXCEPT A. composition. B. radius. C. luminosity. D. lifetime. 29. Why are the terrestrial planets so much smaller than the Jovian ones? A. The Sun has pulled material off of them. B. They spin so fast they flung off most of their original matter which has ended up in the comet cloud. C. Near the Sun, only hard to melt substances which are rare compared to hydrogen could condense. Thus, there was less material to build them. D. They are formed from highly compressible material such as hydrogen and helium so they could be squeezed to a very small size. 30. An optical spectrum of a star it would be a(n) _______ spectrum. A. continuous B. emission C. filtergram D. absorption 31. (Extra credit) Jupiter has been near opposition for much of the semester. Does this mean it has been moving A. prograde, or B. retrograde? 1. D. 2. D. 3. C. 4. A. 5. D. 6. C. 7. C. 8. A. 9. A. 10. D. 11. C. 12. D. 13. D. 14. D. 15. D. 16. A. 17. B. 18. D. 19. A. 20. D. 21. C. 22. B. 23. A. 24. C. 25. A. 26. A. 27. C. 28. A. 29. C. 30. D. 31. B.