Question 1

What have neutrino observatories revealed about the Sun?

Accepted Answer

A)  The radiative zone is bigger than first expected. 
B)  The Sun's magnetic field reverses polarity every 22 years. 
C)  Fusion occurs via the CNO cycle. 
D)  Fusion occurs at about the rate expected from theoretical models of the Sun's interior. 
A)  The radiative zone is bigger than first expected. 
B)  The Sun's magnetic field reverses polarity every 22 years. 
C)  Fusion occurs via the CNO cycle. 
D)  Fusion occurs at about the rate expected from theoretical models of the Sun's interior.

Question 2

An astronomer observing certain regions of the Sun through a spectrometer notices that the spectral lines emitted from these regions are split into two or more components. What does the astronomer conclude about these regions from his observations?

Accepted Answer

A)  The regions contain fast-moving gas. 
B)  The regions are very hot. 
C)  The regions contain strong gravitational fields. 
D)  The regions contain strong magnetic fields. 
A)  The regions contain fast-moving gas. 
B)  The regions are very hot. 
C)  The regions contain strong gravitational fields. 
D)  The regions contain strong magnetic fields.

Question 3

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. 
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.

Question 4

When four protons collide to form helium, what fraction of the original mass of the protons is converted into energy?

Accepted Answer

A)  0.7% 
B)  100% 
C)  0.05% 
D)  4% 
A)  0.7% 
B)  100% 
C)  0.05% 
D)  4%

Question 5

The strength of the magnetic field in a sunspot is estimated from Earth by

Accepted Answer

A)  measuring the size and brightness of the sunspot. 
B)  measuring the size and mass of a prominence suspended above the sunspot. 
C)  measuring the shape of structures seen in the corona above sunspots during solar eclipses. 
D)  observing the wavelength splitting of atomic spectral lines by the Zeeman effect. 
A)  measuring the size and brightness of the sunspot. 
B)  measuring the size and mass of a prominence suspended above the sunspot. 
C)  measuring the shape of structures seen in the corona above sunspots during solar eclipses. 
D)  observing the wavelength splitting of atomic spectral lines by the Zeeman effect.

Question 6

Sunspots appear dark because they

Accepted Answer

A)  are coronal holes. 
B)  are cooler than the surrounding surface. 
C)  are regions from which the light is prevented from escaping by strong magnetic fields. 
D)  have a different chemical composition than the surrounding surface. 
A)  are coronal holes. 
B)  are cooler than the surrounding surface. 
C)  are regions from which the light is prevented from escaping by strong magnetic fields. 
D)  have a different chemical composition than the surrounding surface.

Question 7

Which of these physical products are NOT produced by the Sun during the thermonuclear process in which hydrogen nuclei are combined together in its core?

Accepted Answer

A)  heavy nuclei, such as uranium 
B)  positrons 
C)  helium nuclei 
D)  neutrinos 
A)  heavy nuclei, such as uranium 
B)  positrons 
C)  helium nuclei 
D)  neutrinos

Question 8

The reason sunspots are cooler than the photosphere is that

Accepted Answer

A)  they are points where streams of cool gas from the corona impinge on the photosphere, thereby cooling these regions. 
B)  their powerful magnetic fields inhibit the convective flow of the ionized gases of the photosphere. 
C)  they are holes in the photosphere that reveal the lower temperature gases in the deeper layers. 
D)  their powerful magnetic fields act on the atoms of the photosphere to prevent them from emitting light. 
A)  they are points where streams of cool gas from the corona impinge on the photosphere, thereby cooling these regions. 
B)  their powerful magnetic fields inhibit the convective flow of the ionized gases of the photosphere. 
C)  they are holes in the photosphere that reveal the lower temperature gases in the deeper layers. 
D)  their powerful magnetic fields act on the atoms of the photosphere to prevent them from emitting light.

Question 9

What is a plasma?

Accepted Answer

A)  material in which all the spectral lines exhibit Zeeman splitting 
B)  gas so dense that visible light will not penetrate it 
C)  state of matter consisting of electrons and ionized atoms 
D)  ring around the Sun's equator caused by magnetic effects 
A)  material in which all the spectral lines exhibit Zeeman splitting 
B)  gas so dense that visible light will not penetrate it 
C)  state of matter consisting of electrons and ionized atoms 
D)  ring around the Sun's equator caused by magnetic effects

Question 10

What causes limb darkening?

Accepted Answer

A)  The photosphere at the edge of the Sun's surface is cooler than it is in the middle of the Sun's surface. 
B)  The limb of the Sun is darker than the center because sunspots collect along the limb. 
C)  Light reaching Earth from the limb of the Sun originates in the higher, cooler layers of the Sun. 
D)  Convection within the Sun is more efficient laterally than it is vertically with the result that the middle latitude regions of the Sun's surface are hotter than the poles. 
A)  The photosphere at the edge of the Sun's surface is cooler than it is in the middle of the Sun's surface. 
B)  The limb of the Sun is darker than the center because sunspots collect along the limb. 
C)  Light reaching Earth from the limb of the Sun originates in the higher, cooler layers of the Sun. 
D)  Convection within the Sun is more efficient laterally than it is vertically with the result that the middle latitude regions of the Sun's surface are hotter than the poles.

Question 11

One method that has been used successfully in recent times to investigate the deep interior of the Sun has been to observe

Accepted Answer

A)  regular 5-minute oscillations and fluctuations of the surface. 
B)  the spectrum and behavior of a sunspot, whose roots are deep inside the Sun. 
C)  the progress of a solar-impacting comet. 
D)  physical conditions in the deep interior, using a spacecraft that penetrated into the Sun. 
A)  regular 5-minute oscillations and fluctuations of the surface. 
B)  the spectrum and behavior of a sunspot, whose roots are deep inside the Sun. 
C)  the progress of a solar-impacting comet. 
D)  physical conditions in the deep interior, using a spacecraft that penetrated into the Sun.

Question 12

How much mass will the Sun lose to space during its lifetime, through the solar wind?

Accepted Answer

A)  a few thousandths of its total mass 
B)  only a few millionths of its total mass 
C)  well over one-half of its total mass 
D)  up to 25% of its total mass 
A)  a few thousandths of its total mass 
B)  only a few millionths of its total mass 
C)  well over one-half of its total mass 
D)  up to 25% of its total mass

Question 13

What is helioseismology?

Accepted Answer

A)  study of the Sun's tidal effects in causing earthquakes 
B)  study of the Sun's response to collisions with grazing comets 
C)  study of vibrations in the Sun's interior 
D)  detailed study of the shape of the Sun 
A)  study of the Sun's tidal effects in causing earthquakes 
B)  study of the Sun's response to collisions with grazing comets 
C)  study of vibrations in the Sun's interior 
D)  detailed study of the shape of the Sun

Question 14

The typical speed of spicular material traveling outward from the photosphere in the direction of Earth is 20 km/s. What would be the observed wavelength of the Balmer H $\alpha$  hydrogen spectral line emitted by this gas compared with that from stationary solar material?

Accepted Answer

A)  There will be no shift since the light is emitted by hydrogen gas in both the spicule and the stationary solar material. 
B)  0.044 nm longer than the H $\alpha$ from stationary solar material 
C)  0.000067 nm shorter than the H $\alpha$  from the stationary solar material 
D)  0.044 nm shorter than the H $\alpha$  from stationary solar material 
A)  There will be no shift since the light is emitted by hydrogen gas in both the spicule and the stationary solar material. 
B)  0.044 nm longer than the H $\alpha$ from stationary solar material 
C)  0.000067 nm shorter than the H $\alpha$  from the stationary solar material 
D)  0.044 nm shorter than the H $\alpha$  from stationary solar material

Question 15

The photosphere of the Sun is the

Accepted Answer

A)  visible "surface" of the Sun. 
B)  middle layer of the Sun's atmosphere. 
C)  region of convecting gases below the visible surface of the Sun. 
D)  core of the Sun, where the nuclear energy is generated. 
A)  visible "surface" of the Sun. 
B)  middle layer of the Sun's atmosphere. 
C)  region of convecting gases below the visible surface of the Sun. 
D)  core of the Sun, where the nuclear energy is generated.

Question 16

Of the three ways in which energy is transported in nature, which two are important in the Sun?

Accepted Answer

A)  radiation and conduction 
B)  convection and conduction 
C)  The question is wrong; all three ways in which energy is transported are equally important in the Sun. 
D)  radiation and convection 
A)  radiation and conduction 
B)  convection and conduction 
C)  The question is wrong; all three ways in which energy is transported are equally important in the Sun. 
D)  radiation and convection

Question 17

What is the character of the sunspot cycle?

Accepted Answer

A)  Starting at sunspot minimum, new spots appear uniformly over the Sun, then gradually become concentrated at mid-latitudes as they increase and then decrease in number. 
B)  Starting at sunspot minimum, spots first appear far from the equator, followed by new spots closer to the equator as they increase in number, the latest spots closest to the equator. 
C)  Sunspots increase and decrease in number over 11 years, appearing at random locations between latitudes 10° and 30° from the equator in both hemispheres. 
D)  Starting at sunspot minimum, new spots appear close to the equator, followed by spots farther from the equator as they increase in number, the latest spots dying out at high latitudes. 
A)  Starting at sunspot minimum, new spots appear uniformly over the Sun, then gradually become concentrated at mid-latitudes as they increase and then decrease in number. 
B)  Starting at sunspot minimum, spots first appear far from the equator, followed by new spots closer to the equator as they increase in number, the latest spots closest to the equator. 
C)  Sunspots increase and decrease in number over 11 years, appearing at random locations between latitudes 10° and 30° from the equator in both hemispheres. 
D)  Starting at sunspot minimum, new spots appear close to the equator, followed by spots farther from the equator as they increase in number, the latest spots dying out at high latitudes.

Question 18

What is a prominence on the Sun?

Accepted Answer

A)  large loop of gas supported by magnetic fields 
B)  jet of gas shot upward from an emerging sunspot 
C)  shock wave created by the eruption of a solar flare 
D)  another name for a plage 
A)  large loop of gas supported by magnetic fields 
B)  jet of gas shot upward from an emerging sunspot 
C)  shock wave created by the eruption of a solar flare 
D)  another name for a plage

Question 19

If looking at the center of the Sun, one sees into the base of the photosphere at approximately 5800 K. If looking into the Sun nearer the edge, one might see as far as a layer above the base with a temperature of perhaps 5500 K. According to the Stefan-Boltzmann relation, what is the flux in the center of the solar disk compared to the flux near the edge?

Accepted Answer

A)  5500/5800 = 0.95 
B)  5800/5500 = 1.05 
C)  (5800/5500)2 = 1.11 
D)  (5800/5500)4 = 1.24 
A)  5500/5800 = 0.95 
B)  5800/5500 = 1.05 
C)  (5800/5500)2 = 1.11 
D)  (5800/5500)4 = 1.24

Question 20

The center of the disk of the visible Sun appears brighter than the edges because one sees

Accepted Answer

A)  less radiation from the cooler chromosphere near the edges of the Sun. 
B)  into deeper and hotter layers at the center of the solar disk. 
C)  into deeper and cooler layers at the center of the solar disk. 
D)  a greater contribution from the corona of the Sun at the center of the disk. 
A)  less radiation from the cooler chromosphere near the edges of the Sun. 
B)  into deeper and hotter layers at the center of the solar disk. 
C)  into deeper and cooler layers at the center of the solar disk. 
D)  a greater contribution from the corona of the Sun at the center of the disk.

What have neutrino observatories revealed about the Sun?

An astronomer observing certain regions of the Sun through a spectrometer notices that the spectral lines emitted from these regions are split into two or more components. What does the astronomer conclude about these regions from his observations?

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

When four protons collide to form helium, what fraction of the original mass of the protons is converted into energy?

The strength of the magnetic field in a sunspot is estimated from Earth by

Sunspots appear dark because they

Which of these physical products are NOT produced by the Sun during the thermonuclear process in which hydrogen nuclei are combined together in its core?

The reason sunspots are cooler than the photosphere is that

What is a plasma?

What causes limb darkening?

One method that has been used successfully in recent times to investigate the deep interior of the Sun has been to observe

How much mass will the Sun lose to space during its lifetime, through the solar wind?

What is helioseismology?

The typical speed of spicular material traveling outward from the photosphere in the direction of Earth is 20 km/s. What would be the observed wavelength of the Balmer H _$\alpha$ hydrogen spectral line emitted by this gas compared with that from stationary solar material?

The photosphere of the Sun is the

Of the three ways in which energy is transported in nature, which two are important in the Sun?

What is the character of the sunspot cycle?

What is a prominence on the Sun?

The center of the disk of the visible Sun appears brighter than the edges because one sees

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Exam 11: The Sun: Our Extraordinary Star

What have neutrino observatories revealed about the Sun?

An astronomer observing certain regions of the Sun through a spectrometer notices that the spectral lines emitted from these regions are split into two or more components. What does the astronomer conclude about these regions from his observations?

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

When four protons collide to form helium, what fraction of the original mass of the protons is converted into energy?

The strength of the magnetic field in a sunspot is estimated from Earth by

Sunspots appear dark because they

Which of these physical products are NOT produced by the Sun during the thermonuclear process in which hydrogen nuclei are combined together in its core?

The reason sunspots are cooler than the photosphere is that

What is a plasma?

What causes limb darkening?

One method that has been used successfully in recent times to investigate the deep interior of the Sun has been to observe

How much mass will the Sun lose to space during its lifetime, through the solar wind?

What is helioseismology?

The typical speed of spicular material traveling outward from the photosphere in the direction of Earth is 20 km/s. What would be the observed wavelength of the Balmer H α\alphaα hydrogen spectral line emitted by this gas compared with that from stationary solar material?

The photosphere of the Sun is the

Of the three ways in which energy is transported in nature, which two are important in the Sun?

What is the character of the sunspot cycle?

What is a prominence on the Sun?

The center of the disk of the visible Sun appears brighter than the edges because one sees

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

The typical speed of spicular material traveling outward from the photosphere in the direction of Earth is 20 km/s. What would be the observed wavelength of the Balmer H _$\alpha$ hydrogen spectral line emitted by this gas compared with that from stationary solar material?