1. O4 to Ma: The luminosity of the star...
2. O4 to Ma: The absolute magnitude of the star..
3. O4 to Ma: The life expectancy of the star...
4. O4 to Ma: The physical size of the star...
5. As the volume of a gas cloud decreases in diameter, the density of that gas cloud will...
6. A gas cloud starts off with a certain temperature and with a slight rotating motion. If there is sufficient mass and the cloud begins to contract, the temperature of that cloud will begin to... Think of the Fahrenheit 451 experiment (the tube and plunger).
7. A gas cloud starts off with a certain temperature and a slight rotational motion. If there is a sufficient mass and the cloud begins to contract, the rotational speed of the cloud will begin to.. Think of an ice skater performing a pirouette.
8. If two identical sodium vapor streetlights are viewed simultaneously from a distance of one city block (1/8 mile) and one mile respectively, the streetlamp at a distance of one block will appear how many times brighter than the lamp at a distance of one mile?
a. 8
b. 25
c. 50
d. 64
e. 251
f. 326
9. The magnitude scale quantified by 19th century astronomers was first used by the Greeks two thousand years ago. Choose the correct statement.
a. A change in one magnitude represented a doubling or halving of the light intensity of that star.
b. The brighter the star, the more negative the magnitude.
c. Faint stars, invisible to the unaided eye, were also considered by the Greeks.
d. The brightnesses of the planets, sun, and moon were never considered.
e. A difference in five magnitudes represented an intensity change of 32 or 25.
10. The star with the brightest absolute magnitude in the list is
a. Venus (G2 reflected main sequence).
b. Sirius (A1 main sequence).
c. Polaris (F7 supergiant).
d. the sun (G2 main sequence).
e. Alpha Centauri (G2 main sequence).
11. Until the 19th century, it was impossible to compare the true brightness's of the starts because
a. The magnitude system had not been properly calibrated.
b. The color of the stars, a trait which affects their brightness's, had not been properly investigated.
c. The distances to the stars were unknown.
d. No parallax measurement of a star had ever been successfully made.
e. Spectroscopy was only in its infancy.
12. Which list gives the correct ordering of the various parts of the electromagnetic spectrum from most energetic to least energetic? Not all of the energies of the electromagnetic spectrum are represented in each list.
a. gamma rays, visible, X-rays, radio, microwaves
b. radio, infrared, visible ultraviolet, gamma rays
c. microwaves, radio, gamma rays, infrared, ultraviolet
d. gamma rays, ultraviolet, infrared, microwaves, radio
e. visible, infrared, ultraviolet, microwaves, X-rays
13. Which list gives the correct ordering of the various parts of the electromagnetic spectrum from longest wavelength to shortest wavelength? Not all of the energies of the electromagnetic spectrum are represented in each list.
a. gamma rays, visible, X-rays, radio, microwaves
b. radio, infrared, visible, ultraviolet, gamma rays
c. microwaves, radio, gamma rays, infrared, ultraviolet
d. gamma rays, ultraviolet, infrared, microwaves, radio
e. visible, infrared, radio, ultraviolet, microwaves
14. Which list gives the correct ordering of the various parts of the electromagnetic spectrum from highest frequency to lowest frequency? Not all of the energies of the electromagnetic spectrum are represented in each list.
a. gamma rays, ultraviolet, X-rays, infrared, microwaves
b. gamma rays, X-rays, ultraviolet, visible, infrared
c. microwaves, infrared, visible, X-rays, gamma rays
d. microwaves, radio, X-rays, infrared, ultraviolet
e. visible, infrared, ultraviolet, microwaves, X-rays
15. Which one of the following is not part of the electromagnetic spectrum?
a. ultraviolet radiation
b. cosmic rays
c. infrared light
d. radio light
e. X-rays
f. visible light
16. The frequency of an electromagnetic wave multiplied by its wavelength always equals
a. the speed of light.
b. the speed of sound.
c. one astronomical unit.
d. one light year.
e. a parsec speed.
f. the diameter of the Milky Way
17. There are two basic descriptions of light. Which word relating w one of these descriptions does not belong in the following list?
a. photon
b. energy packet
c. messenger particle
d. wave
e. energy quanta
18. The speed of the various energies of the electromagnetic spectrum is always
a. the same.
b. slowest for the least energetic parts of the spectrum and fastest for the most energetic portions of the spectrum.
c. 186,000 miles per minute.
d. 300,000 kilometers per second.
e. fastest for the highest frequencies and slowest for the lowest frequencies.
19. When the speed of light slows because the electromagnetic energy has passed from a less dense medium to a denser medium, the light is said to be bent or
a. diffracted.
b. Doppler-shifted.
c. homogenized.
d. refracted.
e. reflected.
f. red-shifted.
20. Pick two correct answers. Black body radiation curves allow astronomers to:
a. quantify the energy distribution of stars at different temperatures.
b. understand why stars appear to have different colors to the human eye.
c. calculate the mass of a star.
d. know the temperature of a star.
e. compute the most frequently emitted wavelength of energy that a star is producing.
21. Star A is hotter than star B. Star A will
a. radiate more energy at all wavelengths across its visible and invisible spectrum than star B.
b. be redder than star B.
c. will have a peak energy emission at a shorter wavelength than star B.
d. be less massive than star B.
e. evolve more slowly than star B.
22. According to the Bohr Theory of the atom, when a specific quanta or energy level is absorbed by an electron,
a. the electron will jump from a higher energy level to a lower energy level.
b. the total energy of the atom will become less.
c. the atom will be said to be in an excited state.
d. the atom will become an ion.
e. the atom will start to fluoresce or "glow."
23. If an electron in a hydrogen atom were to jump from the n = 3 level to the n = 2 level,
a. the total energy of the atom would become less.
b. a specific quanta of energy will be released.
c. the atom would return to its ground state.
d. the atom will become more excited.
e. a photon of light visible to the human eye would be emitted.
f. the atom would probably be radioactive.
24. The basis behind absorption spectroscopy or the formation of the absorption spectrum is that
a. elements and compounds when made to incandesce emit light at certain specific wavelengths (colors).
b. certain substances emit electrons in direct proportion to the number of photons being absorbed.
c. a solid, a liquid, or a gas (under high pressure), when made to incandesce, will emit visible radiation in which all wavelengths are represented.
d. gases absorb radiation at certain specific wavelengths from a continuous source. These gases filter the light, preventing most of the light from certain wavelengths from reaching the recording equipment, creating the dark absorption lines.
e. white light is the composite of all the colors found in the visible region of the spectrum.
25. By attempting to analyze the absorption spectrum of the sun or any other star, astronomers can learn what important facts about the object?
a. The laws governing spectroscopy as proposed by Kirchhoff are incorrect.
b. The temperature of the star.
c, The elemental composition of the star.
d. The number of neutrinos per second coming from of the star.
e. The absolute magnitude of the star.
f. How fast the star is rotating.
26. The lights when viewed through "fireworks glasses" (a diffraction grating) from the Sky Deck of Moravian College show
a. are producing a continuous spectrum.
b. are producing an emission spectrum.
c. are absorbing energy like a black body.
d. are producing absorption spectra if viewed through a spectroscope.
e. will show a very beautiful and complete black body radiation curve.
27. The spectral classification of a star that falls along the main sequence of the Hertzsprung-Russell diagram, FAILS to tell astronomers which one of the following characteristics bout that star.
a. color
b. mass
c. apparent magnitude
d. temperature
e. absolute magnitude
28. According to the spectral classification pairs given below, which duo indicates the greatest difference in temperature?
a. A0 to F0
b. B0 to G0
c. L0 to C0
d. O3 to B0
e. F0 to K0
f. A0 to M0
29. The relative strength of the dark absorption lines of stellar spectra are
a. mass dependent.
b. color dependent.
c. wavelength dependent.
d. temperature dependent.
e. composition dependent.
30. When a spectrogram (picture of the spectrum) of the sun is examined, it is found that the darkest absorption lines which are present result from singly ionized calcium (CaII), neutral iron (FeI), and neutral magnesium (MgI). Hydrogen is prominent, but not dominant. This means that
a. the sun contains large quantities of calcium, iron, and magnesium.
b. the sun is composed mostly of hydrogen and helium, but also very significant amounts, of calcium, iron, and magnesium.
c. the sun is not at the correct temperature to cause the hydrogen absorption lines to be dominant, but it is at the correct temperature for the creation of absorption lines of signally ionized calcium, neutral iron, and neutral magnesium.
d. a star at the sun's temperature should also show molecules in its light-emitting portion.
31. The existence of compounds in the spectrum of a star would indicate that this star is
a. very cool
b. far away
c. very young
d. very dim
e. a large star
f. very hot
32. The most massive stars known at present are approximately how many times more massive than the sun?
a. 10-20 times
b. 50-100 times
c. 300 times
d. 500-1000 times
e. 10,000 times
f. Astronomers don't really know.
33. A star with 30 times the mass of the sun would
a. easily shine with a brightness of over 100,000 suns.
b. be unstable and blow up before it could even become a star.
c. would have enough material to change hydrogen into helium for billions of year
d. would appear red in color as a hydrogen-burning star.
e. would be a good candidate for a supernova event.
34. The brightest object listed below would be the star or planet at a magnitude of
a. -3.1.
b. -2.
c. 0.
d. +3.
e. +14.8.
35. The most numerous grouping of stars in the Milky Way Galaxy is found to be of starts classification
a. O.
b. B.
c. G.
d. K.
e. M.
36. The spectral classifications of the stars which are lighting up the bluish arms of spiral galaxies like the Milky Way are
a. O, B.
b. A, F.
c. F, G.
d. G, K.
e. M.
37. The Hertzsprung-Russell diagram allows astronomers to understand
a. the relationship of true stellar brightness and temperature.
b. the relationship between the absolute luminosity of a star and its spectral classification.
c. the evolution of different types of stars.
d. why the universe is accelerating.
e. the relationship of mass to stellar temperature for all stars.
38. Find the INCORRECT statement. The Hertzsprung-Russell diagram
a. can he used to understand the evolution of stars or the age of a star cluster.
b. shows the relationship of the "sliding board" effect of stellar evolution. New stars begin their lives as high luminosity-high mass objects, consume their fuel and gradually over billions of years lose mass and become low luminosity-low mass stars.
c. shows that there is a relationship between the spectral classification of main sequences stars, white dwarf stars, and giant stars with their absolute brightness.
d. shows that there is a relationship between the mass of a hydrogen-burning, star and its absolute magnitude.
e. can be interpreted to show how some stars can be huge while other stars must be very small in size.
39. The Hertzsprung-Russell diagram charts the
a. the mass of a star against its life expectancy.
b. the diameter of a star against its color.
c. the number of star spots (similar to sunspots) which a star contains against the stmt of its magnetic field.
d. the temperature of a star against its absolute magnitude.
e. affect of stars when they go supernova.
40. Stars that are "burning" hydrogen into helium as their main energy source will be found exclusively
a. on the right-hand side of the H-R diagram.
b. on the upper left-hand side of the H-R diagram.
c. along the propeller shaped curve of the H-R diagram.
d. near the lower left-hand side of the H-R diagram.
e. anywhere on the H-R diagram.
41. The position of a main sequence star on an H-R diagram is a result of that star's
a. size.
b. mass.
c. composition.
d. pre-main sequence history.
e. temperature.
42. Stars that are very cool, but extremely luminous are called _______.
43. Starts which are very faint, but have high surface temperatures are called _________.
44. Starts which are very luminous, and have high surface temperatures are called ________.
45. State the name of the brightest (apparent magnitude) main sequences star in the sky _________.
Instructions: Make use of this H-R diagram from question 46 through question 53. The same star may be used multiple times.
46. Which one of the named stars is oldest in terms of its life cycle?
a. Betelgeuse
b. Vega
c. Procyon B
d. Sun
e. Sirius A
f. Deneb
47. Which of the named stars listed below are undergoing core hydrogen burning?
a. Betelgeuse
b. Vega
c. Procyon B
d. Sirius A
e. Deneb
f. Sun
48. Name the stars which are burning helium or heavier elements as fuels?
a. Betelgeuse
b. Vega
c. Procyon B
d. Sun
e. Sirius A
f. Deneb
49. Which one of the named stars listed is closest to death?
a. Betelgeuse
b. Vega
c. Procyon B
d. Sun
e. Sirius A
f. Sirius B
50. Which one of the named stars listed below has the highest absolute luminosity?
a. Betelgeuse
b. Vega
c. Procyon B
d. Sun
e. Sirius A
f. Deneb
51. What condition causes blue stars in the upper left of the H-R diagram to be extremely luminous?
a. Surface temperature
b. Size
52. Which one of the named stars below has the lowest luminosity?
a. Betelgeuse
b. Vega
c. Procyon B
d. Sun
e. Sirius A
f. Deneb
53. The star possessing the lowest luminosity is dimmest because of its surface temperature its size?
a. surface temperature
b. size
54. A shock front
a. is similar to an earthquake, but occurring under a body of water.
b. is an area of higher density created when faster moving matter collides with slower moving matter.
c. is necessary requirement for the formation of stars.
d. is your mother's complete disgust when she discovers the recent websites you have been riewing.
e. can be produced by supernovas, OB associations, and galaxies colliding.
55. Which of the following events could realistically trigger the formation of a star cluster? You are required to state two of them/
a. galactic collisions and sideswipes
b. a supernova explosion
c. gravity
d. random movements of matter
e. another star passing close to our sun.
f. an OB association like the Orion Nebula
56. Pick the Incorrect answer. When a cluster of stars is formed through some shock front mechanism,
a. this may occur through galactic collisions or sideswipes.
b. densities and masses must be sufficiently great in order to allow gravity to collapse the system into a star.
c. the least massive stars normally from first.
d. the first stars that form trigger the evaluation of other stars.
e. eventually light pressure from the formation of the first stars that are born blow the remaining gases in the nebula forming another shock front.
57. During the very early phases of a star's formation, its energy comes from
a. the heating of its gases through gravitational collapse
b. combustion
c. thermonuclear fusion
d. nuclear fission
58. The event that marks the end of a star's existence on the main sequence occurs when the satr
a. ceases core hydrogen burning.
b. becoming a supernova.
c. Produces a planetary nebula with an expanding sphere of gas.
d. initiates hydrogen burning in a shell around an inert (nonreacting) core of helium.
e. initiates helium burning in its core, something called the helium flash.
59. When a star evolves from the main sequence into its red giant phase,
a. the core contracts, increasing fusion (energy production) which causes the outer layers of the star to expand.
b. the core becomes hotter while the "surface" of the star gets hotter.
c. the core gets hotter while the "surface" of the star becomes cooler.
d. the core gets cooler, while the "surface" of the star gets hotter.
e. the core becomes cooler while the "surface" of the star also becomes cooler.
60. When a low mass star like our sun ascends to the red giant region of the H-R diagram, an event known as the helium flash may occur. The helium core is degenerate. It does not obey the perfect gas laws (volume of gas expands when heated, contracts when cooled). When helium burning begins, it rips through the star's core, but not much happens. Eventually, so much energy is released that the core material is forced to rapidly expand out of its state of degeneracy. This slows the helium burning in the core of the star and causes the star to become
a. a high luminosity red supergiant.
b. a luminous red giant.
c. less luminous, but hotter on its exterior.
d. a small, hot white dwarf star.
e. a huge, blue supergiant star.
61. When a massive star ascends into the supergiant branch, the far upper right area of the H-R diagram, this means that
a. leftover hydrogen once again begins to burn in its core.
b. energy production in the core decreases, and the star becomes cooler and smaller.
c. helium burning, begins in a shell surrounding a growing carbon-oxygen rich core.
d. the star expands and becomes larger and cooler, while the core continues to contract and becomes hotter.
e. the star may very well go supernova at sometime in the future.
62. Looking at the H-R diagram shows that there are few stars in the giant and supergiant categories. What causes this situation?
a. The time spent at these locations is brief, so there are few examples.
b. Most stars do not become giants, supergiants, or white dwarfs. These small numbers are reflected when modern H-R diagrams are constructed.
c. Some stars are so faint that they ate difficult to detect.
d. This is one aspect of stellar evolution which is not well understood.
e. The sampling of stars which are used in H-R diagram constructions are not typically
63. Two stars are revolving around other in a binary system. The one star is a 20 solar mass red supergiant while the other luminary is a neutron star. The two stars were never in physical contact. It is fair to say
a. that the neutron star will be evolve into a black hole at some future date.
b. that the neutron star is a rapidly rotating pulsar.
c. that at one time the neutron star was the more massive star in the binary system.
d. that the neutron star was formed by a supernova event.
e. that both stars were never main sequences starts at any time during their regular hydrogen burning phases.
f. that the 20 solar mass main sequences star will not go supernova.
64. An H-R diagram of a nearby star cluster shows that its main sequences stars have a "turn-off position of G4. In other words, it is at this location where starts are migrating off the main sequence to become giants. Our sun is a G2 main sequences star. It is safe to say
a. that the cluster is very old.
b. that the star cluster is older than the sun's entire lifespan.
c. that new OB associations will be found in the near vicinity of this star cluster.
d. that an overabundance of red giants may be seen because the main sequences stars would have luminosities far too low to be viewed.
e. that no white dwarf stars would be observable.