Exploring the Cosmos - Life and Death of Stars (Part 1)
1. What is the name of the Sun's visible surface?
corona
photosphere
lithosphere
chromosphere
2. Two isotopes of the same chemical have the same number of what in their nuclei?
Neutrons
Electrons
Photons
Protons
3. How does a star of spectral type A0 differ from one of spectral type A5.
It is smaller.
It is hotter.
It is bigger.
It is cooler.
4. The spectral sequence of stars in order of decreasing temperature is
FGKMOAB
ABFGKMO
OABMFGK
OBAFGKM
5. The luminosity of a star is proportional to which power of its temperature?
Fourth
Second
Third
Fifth
6. The colour index of a star is indicative of its
Temperature
Luminosity
Distance
Diameter
7. What is our Sun’s spectral type?
F6
G2
A0
K9
8. What temperature range do Main Sequence stars fall into?
3000K to 30000K
30K to 300K
30000K to 300000K
300K to 3000K
9. What is the name given to the process by which elements are formed in stars?
Stellar nucleosynthesis
Stellar construction
Stellar manipulation
Stellar photosynthesis
10. Which element is the most abundant in the universe?
Iron
Hydrogen
Helium
Neon
11. Which process allows for the building up of elements heavier than iron?
Photodisintegration
Helium capture
Neutron capture
The alpha-proces
12. Which is the closest star to our own Sun?
Barnard’s Star
Proxima Centauri
Epsilon Eridani
Betelgeuse
13. The parallax of the nearest star is of the order of
10 arc seconds
1 arc minute
1 arc second
10 arc minutes
14. The star's annular parallax is 0. 4. What is its distance?
2.5 AU
2.5 pc
2.5 Mpc
2.5 LY
15. Roughly how many stars are there in our own galaxy?
100 million
100 billion
1 million
1 billion
16. Which of the following statements is true?
The parallax of an object decreases as the distance from observer to object increases.
The parallax of an object increases as the distance from observer to object increases.
The parallax of an object does not depend on the distance between observer and object.
The parallax of an object decreases as the distance from observer to object decreases.
17. The sun's visible surface is called the
corona.
photosphere.
chromosphere.
lithosphere.
18. The surface temperature of the sun is approximately
10,000 K
3,000 K
50,000 K
6,000 K
19. The luminosity of a star is proportional to the _______ power of its temperature.
third
second
fifth
fourth
20. The colour of the H-alpha line of hydrogen is
red.
blue.
green.
violet.
21. Two isotopes of the same chemical have the same number of _____ in their nuclei.
photons
neutrons
electrons
protons
22. On the main sequence stars are powered by nuclear reactions termed ______ burning.
helium
carbon
oxygen
hydrogen
23. The hydrogen content of the average star is approximately
70%
25%
50%
5%
24. A helium nucleus contains _____ protons.
three
one
two
four
25. A star’s spectral type is most closely related to its
mass.
temperature.
luminosity.
radius.
26. A star of spectral type A0 is slightly ________ than one of spectral type A5.
cooler
hotter
bigger
smaller
27. The sun's visible surface is called the
chromosphere.
lithosphere.
photosphere.
corona
28. The luminosity of a star is proportional to the _______ power of its temperature.
fifth
third
second
fourth
29. The central temperature of the sun is approximately
1,000 K
1,000,000 K
15,000,000 K
6,000 K
30. Roughly how many stars are there in our own galaxy?
1 million
1 billion
100 million
100 billion
31. Who developed the first systematic method for naming stars in 1603?
John Flamsteed
Johann Bayer
Henry Draper
Joseph de Lalande
32. The energy of a photon emitted as a result of an atomic transition is proportional to its
frequency.
wavelength squared.
wavelength.
frequency squared.
33. The spectral sequence of stars in order of decreasing temperature is
OBAFGKM
OABMFGK
ABFGKMO
FGKMOAB
34. Under favourable conditions the faintest stars visible to the naked eye are of magnitude
6
-6
26
16
35. The absolute magnitude of a star is the magnitude it would have if it was at a distance of
1 parsec
10 parsecs
1 AU
100 parsecs
36. If star A is magnitude 2, and star B is magnitude 3, by how many times is star A brighter than star B?
10 times
2.5 times
100 times
25 times
37. The apparent brightness of a star decreases in proportion to the _____ power of its distance.
second
forth
third
first
38. Eclipsing binaries can be regarded as a sub-class of ______ binaries.
X-ray
spectroscopic
visual
astrometric
39. What type of binary star typically has the longest period?
Visual
Spectroscopic
Photometric
Eclipsing
40. Which is the closest star to our own Sun?
Barnard’s Star
Epsilon Eridani
Proxima Centauri
Betelgeuse
41. What is the rough distance from our star to the closest star to our star?
4.3 lightyears
43 parsecs
43 lightyears
4.3 parsecs
42. The spectral sequence of stars in order of decreasing temperature is
FGKMOAB
ABFGKMO
OBAFGKM
OABMFGK
43. The sun is a star of luminosity class
II.
V.
IV.
III.
44. A first magnitude star is _________ than a second magnitude star.
fainter
larger
smaller
brighter
45. What kind of binary was Sirius classified as when its binary nature was first established?
Photometric
Astrometric
Visual
Spectroscopic
46. Eclipsing binaries can be regarded as a sub-class of ______ binaries.
visual
X-ray
astrometric
spectroscopic
47. The sun is a star of luminosity class
V.
III.
II.
IV.
48. The star Algol is a famous example of a binary system which is
eclipsing.
spectroscopic.
astrometric.
X-ray.
49. The luminosity of a star is proportional to its temperature raised to what power?
Forth (i.e. T^4)
Second (i.e. T^2)
Fifth (i.e. T^5)
Third (i.e. T^3)
50. A magnitude 5 star is how many times brighter than a magnitude 10 star?
10.
10000.
100.
1000.
51. Roughly what percentage of observed stars are classed as white dwarfs?
50%
1%
99%
10%
52. The longest period binaries are likely to be of which type?
Photometric
Visual
Spectroscopic
Eclipsing
53. Primordial elements were created early on
in all of the above.
in the life of stars.
in the history of the Universe.
in the life of planets like Earth.
54. In the proton-proton chain, how many hydrogen nuclei are necessary to produce a helium nucleus by nuclear fusion reactions?
Two
Four
Sixteen
Eight
55. Why are conditions ideal for neutron capture deep inside evolved stars?
Hydrogen nuclei are the most abundant deep inside stars and can capture neutrons very easily.
Heavy nuclei are rich in neutrons and tend to attract more neutrons than light nuclei.
The temperature is high enough to overcome repulsive forces between nuclei and free neutrons.
Neutrons are a by-product of many nuclear reactions, so there are many free neutrons available to interact with nuclei.
56. A Hertzsprung-Russell diagram is a plot of stars'
absolute magnitudes as a function of their spectral types.
spectral types as a function of their distances.
distances as a function of their mass.
mass as a function of their absolute magnitudes.
57. The study of typical light curves from Type Ia supernovae indicates that
these occur only in distant galaxies.
radioactive nuclei form as a result of the explosion.
they originate from solar-like stars.
vast amounts of neutrinos are emitted in the explosion.
58. Primordial elements were created in
nuclear experiments on Earth.
supernovae.
the Big Bang.
stellar cores.
59. In the modern deï¬nition of the magnitude scale, a change of 5 in the magnitude of an object corresponds to a change in apparent brightness of exactly a factor of
50
5
100
10
60. The Sun is the brightest object in the sky and has an apparent magnitude of
26.7
-1
1
-26.7
61. Spectroscopic parallax is a technique allowing astronomers to
infer the mass of relatively far-away stars.
determine the temperature of relatively far-away stars.
estimate the size of relatively far-away stars.
measure distances to relatively far-away stars.
62. The apparent brightness of a star is
inversely proportional to the square of its luminosity and proportional to its distance.
inversely proportional to its luminosity and proportional to the square of its distance.
proportional to the square of its luminosity and inversely proportional to its distance.
proportional to its luminosity and inversely proportional to the square of its distance.
63. A star’s luminosity class is determined by
its effective temperature.
its apparent brightness.
the width of its spectral lines.
the abundance of heavy elements in its atmosphere.
64. The lifetime of a main-sequence star that is twice as massive as the Sun is
10 times shorter than our Sun’s lifetime.
the same as our Sun’s lifetime.
10 times longer than our Sun’s lifetime.
unknown unless we know its chemical composition.
65. A spectroscopic binary is a pair of stars that
are very close to each other but can be seen separately with a telescope.
appear by chance to be close to each other but in reality are distant from each other.
are so close to each other that they cannot be seen separately with a telescope.
are distant from each other but share the same spectral features.
66. Stars in the Milky Way
orbit around the Galactic centre.
move randomly.
are fixed.
orbit around the Sun.
67. The annual movement of the stars across the sky as seen from Earth and corrected for parallax is known as
apparent motion.
proper motion.
regular motion.
annual motion.
68. The region of the Sun where most of its visible radiation is released is called
the heliosphere.
the radiative zone.
the visible region.
the photosphere.
69. Stars produce energy during most of their lifetime by
gravitational contraction.
breaking heavy nuclei.
fusing light nuclei.
nuclear fission.
70. Neutron capture is a process in which
bound neutrons in heavy nuclei are captured by surrounding nuclei.
free neutrons are captured by nuclei.
photons are scattered by neutrons.
neutron stars are formed.
71. As the temperature of a blackbody increases, the peak of intensity occurs
at a higher wavelength.
at a higher frequency.
at a higher pressure.
none of the above: the peak of intensity is not affected by the temperature of the blackbody.
72. When comparing colours of main-sequence stars, those stars which appear red in colour are
hotter than those which appear blue.
older than those which appear blue.
cooler than those which appear blue.
younger than those which appear blue.
73. The apparent brightness of a star is
inversely proportional to its luminosity and inversely proportional to the square of its distance from the observer.
proportional to its luminosity and inversely proportional to the square of its distance from the observer.
proportional to its luminosity and proportional to the square of its distance from the observer.
inversely proportional to its luminosity and proportional to the square of its distance from the observer.
74. In a spectroscopic binary system, some information about stellar masses can be obtained by studying
the relative sizes of the stars.
a periodically variable Doppler shift in the observed spectrum.
the proper motion of the stars.
the relative emissions of the stars in the V and B bands.
75. The lifetime of a massive star
is longer than that of a less massive star.
is shorter than that of a less massive star.
is the same as that of a less massive star.
cannot be compared to that of a less massive star.
76. If an object is measured to have a parallax of 1'', how far away is it?
1000 parsecs
10 parsecs
1 parsec
100 parsecs
77. How much faster does the Sun spin on its axis, at its equator, than the Earth does?
36 times
25 times
10 times
50 times
78. Which of the following lists the elements Carbon, Helium, Hydrogen and Oxygen in descending order of abundance in our universe?
Hydrogen, Helium, Carbon, Oxygen
Hydrogen, Oxygen, Carbon, Helium
Oxygen, Hydrogen, Carbon, Helium
Carbon, Helium, Hydrogen, Oxygen
79. The luminosity of a star is dependent on which of the following combinations of stellar radius (r) and surface temperature (T)?
rT^2
rT
r^2 * T^2
r^2 * T^4
80. The two-step process of the photodisintegration of elements, and the direct capture of helium nuclei, is known as what?
The triple-alpha process.
The alpha process.
The neutron capture process.
The Helium capture process.
81. Blackbody curves are drawn from two stars, A and B. If the peak emission frequency of star A is higher than that of star B, what can we infer about the relative temperatures of the stars?
The two stars are at the same temperature.
Star A is colder than star B.
Star B is colder than star A.
It is not possible to infer anything about the two stars temperature without knowing the mass of the star.
82. Which spectral class of stars shows strong levels of ionised helium in their spectra?
A
M
O
F
83. Which of the following lists the spectral classes of stars in order of increasing temperature?
MKGFABO
ABFGKMO
OBAFGKM
MABFGOK
84. Which of the following statements about the apparent brightness of a star is correct?
Changes in luminosity and distance do not affect the apparent brightness.
Increasing the luminosity increases the apparent brightness.
Decreasing the luminosity increases the apparent brightness.
Increasing the distance between star and observer increases the apparent brightness.
85. To which stellar luminosity class do Giant stars belong?
II
IV
V
III
86. The alpha process of element building in stars ends at which element?
Uranium
Iron
Technicium
Hydrogen
87. Certain elements are more abundant in stars than others due to the high levels of which other element?
Neon
Helium
Boron
Oxygen
88. Which of the following statements is true?
Two isotopes of an element will have the same numbers of neutrons, but different number of protons, in their atoms.
Two isotopes of an element will have the same numbers of protons, but different number of neutrons, in their atoms.
Two isotopes of an element will have no protons or neutrons in their atoms.
Two isotopes of an element will have the same numbers of protons and neutrons in their atoms.
89. What is the largest baseline that Earth-based telescopes can have for stellar parallax observations?
8 AU
1 AU
4 AU
2 AU
90. If, observed from Earth, an object has a parallactic angle of 1'', how far away is it from us?
1 km
1 parsec
1 AU
1 lightyear
91. Barnard’s Star exhibits the largest observed proper motion. Roughly how fast is this motion?
9 000 kms^-1
9 000 000 000 kms^-1
90 kms^-1
9 000 000 kms^-1
92. If the density of the Earth is 1, what is the density of our Sun?
1
25
100
0.25
93. Main sequence stars correspond to which group on the luminosity classification scheme?
V
VI
Ib
III
94. How much of the Sun's energy arrives at the Earth every second?
14 000 Wm^-2
140 Wm^-2
140 000 Wm^-2
1 400 Wm^-2
95. As the temperature of a blackbody emitter falls, what happens to its peak emission frequency?
As temperature falls, the peak frequency increases.
As temperature falls, the peak frequency is unchanged.
It is not possible to determine what happens to the frequency without knowing the mass of the star.
As temperature falls, the peak frequency falls.
96. Roughly how much wider is our Sun to the Earth?
10 times wider
100 times wider
1000 times wider
10 000 times wider
97. Into which spectral classification group does our Sun fall into?
M
O
G
B
98. What is the range of surface temperatures of stars on the Main Sequence of the Hertzsprung-Russell diagram?
3 000 to 30 000 K
300 000 to 3 000 000 K
300 to 3 000 K
30 000 to 300 000 K
99. Which luminosity class corresponds to Main Sequence stars?
V
IV
II
III
100. Which of the following correctly lists the spectral classifications of stars in order of decreasing surface temperature.
OFABGKM
OGAFKBM
OMAKFGB
OBAFGKM
101. What is the most abundant element in our universe?
Hydrogen
Oxygen
Helium
Iron
102. What name is given to the process by which carbon atoms are formed from helium atoms?
Helium capture process
Photodisintegration process
Triple-alpha process
Primordial nucleosynthesis process
103. Which of the following is NOT a type of binary star?
Spectroscopic
Astrometric
Visual
Transverse
104. What is the approximate temperature of the corona of our Sun?
15 million K
10 000 K
5 800 K
2 million K
105. 61 Cygni gets its name from the system introduced by John Flamsteed in the 18th century. How was this name derived?
It was discovered in 1861.
It was the 61st star Flamsteed discovered.
It was the 61st star from the west in its constellation.
It can be seen 61 degrees up from the horizon.
106. Which of the following is not an observational class of binary star?
Parallactic
Visual
Photometric
Spectroscopic
107. The sum of the masses of a binary pair is proportional to what power of their orbital period, T?
1/T^4
1/T
1/T^3
1/T^2
108. How does the apparent brightness of a star vary with its luminosity?
The apparent brightness of a star increases when its luminosity increases.
The apparent brightness of a star cannot be measured.
The apparent brightness is not related to its luminosity.
The apparent brightness of a star decreases when its luminosity increases.
109. What value does our Sun have on the apparent magnitude scale?
-26.7
+30
-12.5
+6
110. Which spectral classification corresponds to the hottest stars?
A
G
O
F
111. How many elements are there currently in the periodic table?
113
154
81
10
112. What is the name of the process by which carbon atoms are created from the fusion of helium atoms?
The triple alpha process.
The double alpha process.
Neutron capture.
The alpha process.
113. Which of the following correctly lists the regions of the Sun, starting at its centre and working outwards.
Core, Radiation Zone, Convection Zone, Photosphere
Core, Photosphere, Radiation Zone, Convection Zone
Core, Radiation Zone, Photosphere, Convection Zone
Core, Photosphere, Convection Zone, Radiation Zone
114. What is the approximate temperature of the photosphere of our Sun?
2 million K
10 000 K
15 million K
5 800 K
115. How did Johan Bayer name the stars in the sky? He named them
based on their colour.
in terms of their relative brightness within constellations.
in the order he found them.
in terms of their co-ordinates in the sky.
116. Which is the closest star to our own Sun?
Epsilon Eridani
Barnard's Star
Proxima Centauri
Betelgeuse
117. At roughly what distance is the closest star to our own?
43 lightyears
43 parsecs
4.3 parsecs
4.3 lightyears
118. A star's luminosity is proportional to its surface temperature raised to what power?
Second
Third
First
Fourth
119. Which element is the second most abundant in our universe?
Helium
Silicon
Hydrogen
Iron
120. Which of the following types of stars are most abundant in the universe?
Blue giants
Red dwarfs
White dwarfs
Red giants
121. Which of the following statements is false?
Hydrogen lines are strong in stars with surface temperatures below 4 000 K.
Hydrogen lines are strongest in stars with surface temperatures around 10 000 K.
Spectra of stars with surface temperatures greater than 25 000 K usually show strong absorption lines of singly ionised helium.
Hydrogen absorption lines in the spectra of very hot stars are relatively weak.
122. Which of the following correctly lists the spectral stellar classes in order of descending temperature?
OBAGFKM
OBAFGKM
OBAMFGK
OBAKMGF
123. How is our Sun classed on the spectral classification scale?
O9
B8
G2
F0
124. Which of the following statements is true?
The apparent brightness of a star increases as its luminosity increases.
The apparent brightness of a star decreases as its luminosity increases.
The apparent brightness of a star is unaffected by the distance from which it is observed.
The apparent brightness of a star increases as the distance it is being observed at increases.
125. If star A is magnitude 2, and star B is magnitude 3, by how many times is star A brighter than star B?
25 times
10 times
100 times
2.5 times
126. The Lyman series of hydrogen lines are in the __________ part of the spectrum.
ultraviolet
visible
infrared
X-ray
127. A star's spectral type is most closely related to its
luminosity
temperature
mass
radius
128. The sun's visible surface is called the
corona.
lithosphere.
photosphere.
chromosphere.
129. Hydrogen burning converts slightly less than __________ of the rest mass into energy.
15%
10%
1%
5%
130. A typical stellar velocity with respect to the sun would be of order
2 km per second.
20 km per second.
2 000 km per second.
200 km per second.
131. The sun's angular diameter is approximately
30 arcminutes.
30 radians.
30 arcseconds.
30 degrees.
132. The sun is a star of luminosity class
V
IV
III
II
133. Short period binaries are almost always
astrometric
visual
eclipsing
spectroscopic
134. The star Algol is a famous example of a binary system which is
X-ray
astrometric
spectroscopic
eclipsing
135. The luminosity of a main sequence star increases with its mass approximately to the power
4.5
1.5
2.5
3.5
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