ASTR 2003H Final Exam 5/3/2003 Version 1 1. The Milky Way is about _______ LY across. (a) 1,000 (b) 10,000 (c) 100,000 (d) 1,000,000 2. Interstellar hydrogen emits at a wavelength of __ cm. (a) 10 (b) 18 (c) 21 (d) 32 3. Classify the Milky Way: (a) E5 (b) Sb (c) Sg (d) Irr. II 4. Most of the mass of the Milky Way is (a) baryons (b) protons (c) leptons (d) dark matter. 5. Almost all the helium in the universe was produced about _____ after the Big Bang. (a) 3 micro-seconds (b) 3 milli-seconds (c) 3 minutes (d) 300,000 years 6. We have now detected Earth-like planets orbiting nearby stars. (a) true (b) false 7. About ___ % of stars near the Sun are main-sequence stars. (a) 10 (b) 50 (c) 75 (d) 90 (e) 99 8. The Doppler shift measures the (a) momentum (b) kinetic energy (c) transverse velocity (d) radial velocity. 9. A ZAMS star of which spectral type will evolve the slowest? (a) G (b) B (c) M (d) F (e) O 10. Type ___ supernovae are excellent "standard candles." (a) Ia (b) II (c) IIIb (d) IV 11. Globular clusters are found in the ______ of the Galaxy. (a) plane (b) halo (c) corona 12. Interstellar reddening is due to interstellar (a) gas (b) dust (c) magnetic fields. 13. Pulsars are (a) white dwarfs (b) red giants (c) red dwarfs (d) neutron stars. 14. The Earth is about ___ the size of the Sun. (a) 1/10 (b) 1/20 (c) 1/50 (d) 1/100 15. The craters on the Moon are volcanic in origin. (a) true (b) false - tectonic in origin (c) false - formed by impacts 16. Saturn is mainly made of (a) hydrogen (b) helium (c) silicate rock (d) basalt. 17. Sunspots are associated with (a) aurorae (b) fusion reactions (c) magnetic fields (d) spicules. 18. Gas pressure depends on the _____ of the gas. (a) mass (b) size (c) radioactivity (d) temperature 19. The chemical composition of a planetary body depends mainly on the _______ at which it formed. (a) temperature (b) density (c) time 20. A photon of wavelength 4000 Å is ________ than one of wavelength 4010 Å. (a) bluer (b) redder (c) less energetic 21. Two stars have the same luminosity, but one is cooler than the other. The cooler one must be the ______ one. (a) bigger (b) more massive (c) older (d) more evolved. 22. The Sun has a(n) _________ spectrum. (a) continuous (b) emission-line (c) absorption-line (d) fluted 23. The movement of the Earth's rotational axis over 26,000 years is known as (a) precession (b) nutation (c) osculation (d) gyration (e) eccentric anomaly. 24. _______ was the first person to use elliptical planetary orbits. (a) Aristotle (b) Galileo (c) Newton (d) Kepler (e) Copernicus 25. As an interstellar gas and dust cloud collapses to form stars and planets, the cloud spins (a) faster (b) slower (c) at the same rate. 26. Blue light has a _____ wavelength than red light. (a) longer (b) shorter (c) faster 27. A hot, low density gas radiates light with a(n) _______ spectrum. (a) continuous (b) emission-line (c) absorption-line (d) fluted 28. The ______ contains a grating. (a) reflecting telescope (b) refracting telescope (c) spectrometer (d) goniometer 29. The different phases of the Moon are due to the Earth's shadow. (a) true (b) false 30. Some stars never set below the horizon as seen at Fayetteville. (a) true (b) false 31. The Sun moves along the (a) equator (b) ecliptic (c) meridian (d) solstice line. 32. The size of the Moon's orbit is (a) increasing (b) decreasing (c) staying the same. 33. The atmosphere of Venus is mainly (a) nitrogen (b) oxygen (c) hydrogen (d) carbon dioxide. 34. The atmosphere of Jupiter is mainly (a) nitrogen (b) oxygen (c) hydrogen (d) carbon dioxide. 35. The Oort cloud contains (a) young stars (b) old stars (c) gas (d) comets. 36. If a meteorite falls to the ground, it is most likely a(n) (a) stony type (b) iron (c) stony-iron. 37. Due to __________ early in its history, the Sun now spins relatively slowly. (a) conservation od angular momentum (b) condensation (c) angular retardation (d) magnetic braking 38. The hottest stars are the _____ ones. (a) most massive (b) reddest (c) bluest 39. The Luminosity measures the _____ of a star. (a) mass (b) size (c) energy output. 40. Binary stars are relatively (a) rare (b) common. 41. Hydrogen burning is synonymous with (a) red giants (b) supergiants (c) main-sequence stars (d) white dwarfs. 42. Lightweight stars become ______ eventually. (a) pulsars (b) white dwarfs (c) neutron stars (d) black holes 43. The iron in your blood comes from (a) HI regions (b) planetary nebulae (c) supernovae (d) red giants 44. It you dumped enough mass onto a white dwarf, it would collapse. (a) true (b) false 45. Reflection nebulae are caused by (a) gas (b) dust (c) glass particles (d) comets. 46. _______ galaxies usually contain no dust. (a) Elliptical (b) Normal spiral (c) Barred spiral (d) Irregular 47. Our Local Group of galaxies within a few million LY contains several quasars. (a) true (b) false 48. The assumption of homogeneity and isotropy is known as (a) the Cosmological Principle (b) the Einstein Assumption (c) the Eddington Principle (d) the Cosmological Constant. 49. The study of high-redshift __________ shows that the expansion of the universe is accelerating. (a) supernovae (b) galaxies (c) quasars (d) Seyferts 50. The 3K radiation began its journey to us about ________ years ago. (a) 3,000 (b) 30,000 (c) 4.6 billion (d) 14 billion