Download Astr40 HWIII(new) - Empyrean Quest Publishers

ASTRONOMY 40, HOMEWORK III (new)
1. The higher a star's mass, the higher its core temperature. (T or F)
2. Higher mass stars on the main sequence have lower luminosities. (T or F)
3. Star clusters have stars of different masses, born about the same time. (T or F)
4. Stars with lower mass have shorter lifetimes. (T or F)
5. A low mass star which finishes fusing all the H to He in its core, leaves the main sequence
contracts, and soon
A. begins the cooling off phase as a white dwarf.
B. burns He in its core. C. becomes a protostar.
6. In the next phase after the main sequence, a star becomes
A. larger.
B. redder.
C. more luminous. D. A and C.
E. A, B, and C.
7. In helium fusion, how many He nuclei fuse to make carbon?
A. 2 B. 3 C. 4 D. 5
8. For a low mass star: after helium fusion begins, is stabilized, and the red giant shrinks a bit,
then the star is on what path in the HR diagram?
A. The helium flash B. the main sequence C. the horizontal branch
9. The ejection of 10-20% of the mass of a low mass star into space when Helium burning is
completely finished produces a colorful glowing gas cloud with a white dwarf in the center. This
glowing cloud is called
A. A Planetary Nebula B. A Red Giant C. A Reflection Nebula D. A Brown Dwarf
10. A White Dwarf, the death state of a low mass star, is made of Carbon and a little
A. H
B. He C. O (Oxygen)
D. Fe (Iron)
11. The CNO process rather than the P-P process dominates for He production in high mass
stars. (T or F)
12. The Big bang made a substantial amount of carbon by the triple-alpha process. (T or F)
13. Fluorine can be made by Helium capture. (T or F)
14. Iron is the heaviest element made in abundance in massive stars. (T or F)
15. Higher abundance of elements with an even number of protons is an indication of
A. alpha decay. B. helium capture. C. proton escape.
16. Electrons in the presence of great pressure can be squeezed into protons to make
A. electrons. B. helium atoms. C. neutrons.
17. The closest supernova in 4 centuries is called
A. Supernova I. B. Supernova 1987A. C. the Branch Supernova.
18. The Pauli Exclusion principle which says that no two electrons can occupy the same state,
means that electrons need a certain amount of space. This is what holds up a White Dwarf
against further collapse and is called
A. electron degeneracy. B. Hydrogen pressure. C. neutral electrical pressure.
19. Higher mass White Dwarfs are ___________ than lower mass.
A. larger B. smaller C. the same same size
20. A White Dwarf cannot be more massive than
A. the sun. B. 1.4 solar masses. C. Jupiter.
21. A white dwarf in a companion sitiuation may gain enough mass to get hot enough for a
sudden nuclear explosion called a nova. (T or F)
22. A supernova explosion for a companion white dwarf happens when it is hot enough to fuse
carbon into heavier elements. This completely explodes the white dwarf. (T or F)
23. The light curve (versus time) for a massive star supernova (type II) and a white dwarf
supernova (Type Ia) is the same. (T or F)
24. Electron degeneracy pressure outward is overcome by gravity's inward pull when a neutron
star is made. (T or F)
25. The way we learned observationally that neutron stars existed was by observing
A. neutron spectra. B. quasars. C. pulsars.
26. Which spins fastest: a star, a white dwarf, a neutron star, the earth?
A. a star B. a white dwarf C. a neutron star D. the earth
27. Light can escape from a black hole, if the black hole is small enough. (T or F)
28. The surface of a black hole, at which the escape velocity is the speed of light is called
A. the singularity
B. the event horizon
C. the ergosphere
29. A 3 solar mass black hole's event horizon is about the size of
A. a neutron star, or a small city B. the sun
C. the earth's orbit
30. The minimum mass for a stellar black hole (discovered by Robert Oppenheimer) is
A. the sun's mass
B. 3 times the sun's mass
C. 10 times the sun's mass
31. Nearer the event horizon of a black hole, time passes
A. the same B. slower
C. faster
32. Besides having a gravitational effect of over 3 solar masses, a stellar black hole in companion
will be a strong x-ray source. (T or F)
33. Gamma rays burst could NOT be caused by the formation of black holes. (T or F)
34. Dark lanes across the band of the Milky Way are truly devoid of stars. (T or F)
35. The spiral arm disk of the Milky Way is roughly how many light years across?
A. 10,000
B. 100,000
C. a million
36. Stars in the disk of the Milky Way orbit in circles. (T or F)
37. There is a mass of about a hundred billion solar masses inside of the Sun's orbit about
galactic center. The sun' orbital radius and velocity tells us that. (T or F)
38. Spiral arms of a spiral galaxy are waves of star formation passing through the interstellar
medium. (T or F)
39. The disk stars of the Milky Way formed before stars in the Halo. (T or F)
40. The center of our galaxy most likely contains
A. numerous small black holes B. a supermassive black hole C. a verified wormhole
D. a low density of stars
41. A spiral galaxy is composed of a halo, a disk, and a central bulge, or galactic nucleus. (T or
F)
42. The disk of the galaxy contains only old stars. (T or F)
43. The center of the central bulge, or galactic nucleus, of a spiral galaxy contains old stars only,
just like which type of galaxy?
A. Lenticular B. Normal-sized Elliptical C. Irregular D. Barred Spiral
44. Edwin Hubble's arrangement of galaxy classes is called ___________ . Search online to get
name.
A. Hubble's Bubble B. The Hubble Tuning Fork C. The Hubble Telescope
45. Supergiant elliptical galaxies are more common in which type of galactic cluster?
A. Large
B. Small
C. Medium
46. For astronomers, Hubble's Law, a plot of recession velocity of distant galaxies versus
distance, might just as well be plotted as recession velocity versus lookback time. (T or F)
47. The most evolved galaxies we see are also the most distant. (T or F)
48. The lump of gas destined to create a galaxy--before stars are formed--is called
A. an embryonic galaxy. B. a pre-galaxy. C. a protogalactic cloud.
49. What characteristic of the protogalactic cloud could determine the size of the resulting disk?
A. initial energy B. initial momentum
C. initial angular momentum D. initial lumpiness
50. The epoch in which galaxies collide the most is
A. the current epoch.
B. the middle epoch of age.
formation.
C. the ancient epoch right after galactic