Question 1

Of the three ways in which heat energy is transmitted from one place to another (radiation,conduction,convection) ,which is/are important in carrying heat from the solar interior to the surface of the Sun?

Accepted Answer

A)   radiation and convection
B)   radiation alone, by photons of energy
C)   conduction and convection
D)   conduction, convection, and radiationE) All of the above
F) A) and D)

Question 2

Who first postulated that hydrogen fusion reactions are responsible for generating the energy produced by the Sun?

Accepted Answer

A)   Stephen Hawking
B)   Albert Einstein
C)   George Gamow
D)   Arthur EddingtonE) None of the above
F) A) and B)

Question 3

The solar wind originates primarily:

Accepted Answer

A)   near the solar equator, where solar spin reduces the gravitational field.
B)   in flare explosions.
C)   in sunspots.
D)   in coronal holes, cooler, lower-density regions in the corona.E) None of the above
F) A) and B)

Question 4

What is the difference between a filament and a prominence?

Accepted Answer

A)   A filament is a crack in the photosphere, while a prominence is an outflow of gas into the corona.
B)   Filaments are the openings through which charged particles escape the Sun to become the solar wind. Prominences are the clouds of charged particles on their way off the Sun.
C)   Prominences are the outflow of particles from the Sun's poles. Filaments are dark bands around the Sun's equator.
D)   Filaments and prominences are two views of the same phenomenon. Filaments are prominences seen in profile on the limb of the Sun.E) B) and C)
F) A) and D)

Question 5

The rotation of the Sun is:

Accepted Answer

A)   slowest at the equator, faster at mid-latitudes, and fastest near the poles.
B)   fastest at the equator, slowest at mid-latitudes, and spinning up to intermediate speeds around the poles.
C)   fastest at mid-latitudes, slower at the equator, and slowest near the poles.
D)   fastest at the equator, slower at mid-latitudes, and slowest near the poles.E) B) and D)
F) All of the above

Question 6

What is the MAIN source of the energy radiated by stars?

Accepted Answer

A)   Chemical reactions combine hydrogen and helium to produce energy.
B)   Protons are destroyed and converted into pure energy as described by Einstein's mass-energy relationship.
C)   Less stable nuclei combine to form more stable nuclei with a consequent release of energy.
D)   gravitational collapse as described by the Kelvin-Helmholtz contractionE) None of the above
F) A) and D)

Question 7

Astronomers have compared the relative abundances of different isotopes of neon found in Moon rocks with those found in the solar wind.What conclusion have they drawn?

Accepted Answer

A)   The Sun is much younger than previously thought.
B)   The Sun was much hotter in the past than was previously believed.
C)   The Sun was much cooler in the past than was previously believed.
D)   The Sun has maintained a much more constant temperature than was previously believed.E) B) and D)
F) C) and D)

Question 8

Sunspots are regions where the Sun's magnetic field penetrates the photosphere.What holds each spot together?

Accepted Answer

A)   the mutual attraction of the magnetic field lines
B)   the attraction of the magnetic field lines for the plasma inside the sunspot
C)   rapid circulation of plasma around the field region
D)   gravitational attraction within the colder, more condensed gases within the spotE) C) and D)
F) A) and B)

Question 9

What stops the Sun from collapsing under the force of its own gravity?

Accepted Answer

A)   The interior of the Sun is under such high pressure that it is a liquid, and liquids are incompressible.
B)   Neutrinos from the Sun's core collide with gas atoms and prevent them from falling inward.
C)   Ions and electrons in the Sun are pushed apart by the electric forces between their charges.
D)   The Sun is held up by gas pressure due to the very high temperature inside it.E) None of the above
F) A) and B)

Question 10

In carrying energy through the interior of the Sun,there are many collisions between particles (photons,ions,atoms) .What is the net direction of the energy flow in these collisions?

Accepted Answer

A)   The collisions are random, the energy flows equally in all directions, and it is only by chance that some photons carry energy out of the Sun.
B)   The collisions generally result in energy flow from the core, where temperatures are higher and the particles are moving faster, toward the outer layers where temperatures are lower and particles are moving more slowly.
C)   The collisions generally result in energy flow from the core, where particles are more massive and thus carrying more energy, toward the outer layers where particles are less massive and thus carry less energy.
D)   Because of the higher temperatures toward the core, the particles there are mostly ionized. The electric charge of these ionized particles repels particles from further out from penetrating the core. Thus energy flow is primarily outward.E) A) and D)
F) B) and C)

Question 11

What is a typical magnetic field strength inside a sunspot?

Accepted Answer

A)   a few times stronger than Earth's magnetic field
B)   a million times stronger than Earth's magnetic field
C)   about 1% of the strength of Earth's magnetic field but still strong for low-density gases on the Sun
D)   a few thousand times stronger than Earth's magnetic fieldE) A) and B)
F) A) and C)

Question 12

Is there a connection between plages and sunspots?

Accepted Answer

A)   No, sunspots are a photospheric phenomenon, while plages occur in the chromosphere.
B)   Yes, the magnetic fields that result in sunspots in the photosphere continue on up through the chromosphere, where they produce plages.
C)   Yes, the magnetic fields that result in sunspots in the photosphere compress the gases above the photosphere, and this pressure creates plages in the chromosphere.
D)   Yes, the five minute oscillations of the photosphere push the sunspots up into the chromosphere every five minutes, thus resulting in plages.E) All of the above
F) None of the above

Question 13

One of the effects which accompanied the Maunder minimum in sunspot numbers during the late seventeenth and early eighteenth centuries was:

Accepted Answer

A)   a severe drought in western North America.
B)   an unusual heat wave in Europe.
C)   the Black Plague.
D)   the onset of El Niño.E) None of the above
F) A) and D)

Question 14

Galileo observed the phenomenon of solar rotation in the early 1600s by:

Accepted Answer

A)   noting the periodic (monthly)  variation of auroral disturbances, or northern lights.
B)   watching bright regions of hydrogen gas drift across the Sun.
C)   measuring the motion of sunspots across the solar surface.
D)   measuring the Doppler shift of hydrogen spectral lines from the east and west limbs of the Sun.E) B) and D)
F) None of the above

Question 15

The time it takes for neutrinos generated in the thermonuclear reactions at the center of the Sun to escape from its surface is:

Accepted Answer

A)   instantaneous because they travel faster than the speed of light.
B)   about 1 million years.
C)   about 1 year.
D)   a few seconds.E) None of the above
F) C) and D)

Question 16

How are spicules formed in the Sun's chromosphere?

Accepted Answer

A)   Spicules are formed from material on the tops of granules "tossed" to higher altitudes by the oscillations of the Sun's surface.
B)   Spicules are formed from plasma carried upward along with the magnetic field lines at the edges of supergranules.
C)   Spicules form where the Sun's twisted magnetic field lines break through the photosphere.
D)   Spicules are the remnants or "stumps" of solar prominences that have broken free of the magnetic fields that confine them and have erupted out into space.E) A) and B)
F) None of the above

Question 17

When two protons and two neutrons combine to form ⁴He,the helium nucleus is less massive than the sum of the four original particles used to construct it.What is the significance of this result?

Accepted Answer

A)   The lost mass is transferred into energy.
B)   The mass is lost through friction.
C)   The "lost" mass can be accounted for by the masses of the particles emitted as radioactive decay during the interaction.
D)   The mass disappears without a trace.E) A) and B)
F) B) and C)

Question 18

By how much does the mass of the Sun decrease each second because of the energy radiated from it (its luminosity) ? (See the discussion in Discovery 9-1 in Comins,Discovering the Essential Universe,6th ed.)

Accepted Answer

A)   6.0 × 10¹¹ kg
B)   2.0 × 10⁷ kg
C)   3.9 × 10²⁶ kg
D)   4.3 × 10⁹ kgE) A) and B)
F) A) and C)

Question 19

What name is given to a brighter region in the chromosphere,often in association with a sunspot?

Accepted Answer

A)   filament
B)   plage
C)   granule
D)   prominenceE) A) and D)
F) None of the above

Question 20

The centers of the granular cells on the surface of the Sun appear to be brighter than the edges of the cells because:

Accepted Answer

A)   higher magnetic field strength at the centers condenses and heats the gases there.
B)   the centers are composed of gases that are different from the gases that compose the edges.
C)   gases at the centers are more transparent than gases at the edges, allowing us to view deeper and hotter layers.
D)   the centers are hotter than the edges.E) All of the above
F) A) and B)

Exam 9: The Sun: Our Extraordinary Ordinary Star

Astronomers have compared the relative abundances of different isotopes of neon found in Moon rocks with those found in the solar wind.What conclusion have they drawn?

Correct AnswerverifiedShow Answer

Is there a connection between plages and sunspots?

Correct AnswerverifiedShow Answer

The solar wind originates primarily:

Correct AnswerverifiedShow Answer

One of the effects which accompanied the Maunder minimum in sunspot numbers during the late seventeenth and early eighteenth centuries was:

Correct AnswerverifiedShow Answer

By how much does the mass of the Sun decrease each second because of the energy radiated from it (its luminosity) ? (See the discussion in Discovery 9-1 in Comins,Discovering the Essential Universe,6th ed.)

Correct AnswerverifiedShow Answer

What is the MAIN source of the energy radiated by stars?

Correct AnswerverifiedShow Answer

In carrying energy through the interior of the Sun,there are many collisions between particles (photons,ions,atoms) .What is the net direction of the energy flow in these collisions?

Correct AnswerverifiedShow Answer

Sunspots are regions where the Sun's magnetic field penetrates the photosphere.What holds each spot together?

Correct AnswerverifiedShow Answer

The rotation of the Sun is:

Correct AnswerverifiedShow Answer

What stops the Sun from collapsing under the force of its own gravity?

Correct AnswerverifiedShow Answer

Who first postulated that hydrogen fusion reactions are responsible for generating the energy produced by the Sun?

Correct AnswerverifiedShow Answer

The time it takes for neutrinos generated in the thermonuclear reactions at the center of the Sun to escape from its surface is:

Correct AnswerverifiedShow Answer

What name is given to a brighter region in the chromosphere,often in association with a sunspot?

Correct AnswerverifiedShow Answer

How are spicules formed in the Sun's chromosphere?

Correct AnswerverifiedShow Answer

Galileo observed the phenomenon of solar rotation in the early 1600s by:

Correct AnswerverifiedShow Answer

What is the difference between a filament and a prominence?

Correct AnswerverifiedShow Answer

What is a typical magnetic field strength inside a sunspot?

Correct AnswerverifiedShow Answer

Of the three ways in which heat energy is transmitted from one place to another (radiation,conduction,convection) ,which is/are important in carrying heat from the solar interior to the surface of the Sun?

Correct AnswerverifiedShow Answer

The centers of the granular cells on the surface of the Sun appear to be brighter than the edges of the cells because:

Correct AnswerverifiedShow Answer

When two protons and two neutrons combine to form ⁴He,the helium nucleus is less massive than the sum of the four original particles used to construct it.What is the significance of this result?

Correct AnswerverifiedShow Answer

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