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