Deck 16: The Sun: Our Parent Star

Question 1

Granulation is the most obvious proof of solar convective energy transport.

Answer 1

True

Question 2

We know the Sun rotates differentially by observing sunspots; as with Jupiter the solarequator rotates the fastest.

Answer 2

True

Question 3

A sunbather on the clear day is receiving about 500 watts of solar power.

Answer 3

True

Question 4

The energy of the Sun starts as radiation, but is actually transported to its surface byconvection, where it is radiated off into space at last.

Question 5

The Sun's density is about the same as Saturn's.

Question 6

Sunspots are only about 2,000 K cooler than the much brighter photosphere.

Question 7

The concept of hydrostatic equilibrium is critical to understanding how the Sun has remainedstable long enough for life to evolve here.

Question 8

The photosphere is about 100 times the diameter of the Earth, and large sunspots are largerthan our whole planet.

Question 9

The Sun is a fairly normal star.

Question 10

The Sun's luminosity is greatest when there are few or no sunspots on the Sun.

Question 11

Scientists suspect changes in the flow of the Sun's Conveyor Belt caused the Sun to be lessactive in 2008 and 2009 than had been seen in almost 100 years.

Question 12

Solar activity cannot disrupt communications on Earth.

Question 13

The Sun's mass and volume are over a million times that of our Earth.

Question 14

At very large distances from the Sun, its corona turns into the solar wind.

Question 15

The Sun's magnetic field has been traced out far beyond the orbit of Pluto and even Sedna.

Question 16

Using the observations of the Solar and Heliospheric Observatory (SOHO)and SolarDynamics Observatory (SDO), it may be possible to predict mass ejections from the Sun days inadvance.

Question 17

The solar corona produces a lot more X-rays than it does visible light.

Question 18

The solar corona is much cooler than the Sun's surface; hence we must wait for a total solareclipse to glimpse it with the naked eye.

Question 19

As with Uranus, the solar equator rotates slower than sunspots at higher latitudes.

Question 20

Prominences hanging off the limb of the Sun are the same as filaments seen in front of thedisk.

Question 21

The density of the Sun is most similar to which object?

A)Halley's Comet's nucleus
B)the Earth
C)Mercury
D)the Moon
E)Jupiter

Question 22

The proton-proton chain requires a temperature of 100 million K to get started.

Question 23

Both the gravitational and electromagnetic forces obey the inverse square law, and extendinfinitely outward in their effects.

Question 24

The light we see from the Sun comes from which layer?

A)troposphere
B)chromosphere
C)photosphere
D)ionosphere
E)corona

Question 25

The solar constant measures the energy received by the Earth from the Sun per square meter.This is then used to determine:

A)the Sun's radius.
B)the Sun's temperature.
C)the Sun's mass.
D)the Sun's luminosity.
E)the Sun's rotational period.

Question 26

Auroras are most brilliant during periods of increased solar activity.

Question 27

The solar constant is a measure of:

A)the energy received from the Sun on Earth's surface.
B)the energy received from the Sun at the location of Earth.
C)the energy received from the Sun at any location in the solar system.
D)the energy emitted by the Sun at the photosphere.
E)the total energy emitted by the Sun in all directions.

Question 28

The vibrations of the Sun reveal information about:

A)the temperature of the core of the Sun.
B)the structure of the atmosphere of the Sun.
C)the interior structure of the Sun.
D)the production of energy in the Sun.
E)the magnetic field of the Sun.

Question 29

From inside out, which is in the correct order for the structure of the Sun?

A)core, convective zone, radiative zone
B)photosphere, radiative zone, corona
C)radiative zone, convective zone, chromosphere
D)core, chromosphere, photosphere
E)convective zone, radiative zone, granulation

Question 30

By what mechanism does solar energy reach the Sun's photosphere from the layer justunderneath it?

A)differentiation
B)ionization
C)radiation
D)convection
E)conduction

Question 31

In the proton-proton cycle, you must first make deuterium, then helium.

Question 32

About what percent of the incoming energy from the Sun reaches Earth's surface?

A)80-100%
B)70-90%
C)60-80%
D)50-70%
E)30-60%

Question 33

The above diagram indicates that:

A)the Sun is most dense somewhere between its surface and its core.
B)the Sun is least dense somewhere between its surface and its core.
C)the Sun is more dense at its surface than at its core.
D)the Sun is more dense at its core than at its surface.
E)the Sun has about the same density throughout its interior.

Question 34

Why couldn't you stand on the Sun's surface?

A)The Sun has no surface at all...the photosphere is an illusion.
B)You could stand on the surface.
C)The Sun doesn't have a solid surface.
D)The Sun's surface is too highly magnetized for anything to survive there.
E)You could stand on it, if a sufficiently protective spacesuit could be designed.

Question 35

Hydrostatic equilibrium in our Sun is the balance between:

A)convection and radiation.
B)convection and gravitation.
C)pressure and radiation.
D)radiation and gravitation.
E)gravitation and pressure.

Question 36

The temperature of the layer of gas that produces the visible light of the Sun is:

A)3,500 K.
B)5,800 K.
C)12,300 K.
D)300,000 K.
E)15 million K.

Question 37

The area in the Sun's atmosphere located above the chromosphere (1,500-10,000 km)wherethe temperature rises dramatically is called the:

A)photosphere.
B)corona.
C)solar wind.
D)transition zone.
E)convection zone.

Question 38

How many planet Earths could fit inside the Sun?

A)110
B)about a thousand
C)a little over a million
D)almost ten million
E)close to a billion

Question 39

The luminosity of the Sun is a measure of:

A)the energy received by the Sun on Earth's surface.
B)the energy received by the Sun at the location of Earth.
C)the energy received by the Sun at any location in the solar system.
D)the energy emitted by the Sun at the photosphere.
E)the total energy emitted by the Sun in all directions.

Question 40

In the proton-proton cycle, .007 of the mass ends up as energy, not helium.

Question 41

The outward pressure of hot gas in the Sun:

A)is balanced by the inward gravitational pressure.
B)is increasing the Sun's diameter.
C)is cooling the photosphere.
D)is responsible for variations in the sunspot cycle.
E)weakens the magnetic field.

Question 42

The percentage (by mass)of the Sun that is hydrogen is about:

A)91%.
B)71%.
C)27%.
D)9%.
E)less than 1%.

Question 43

When the chromosphere can be seen during a solar eclipse, it appears:

A)invisible.
B)violet.
C)blue.
D)yellow.
E)red.

Question 44

The Sun's magnetic field is measured by:

A)the Zeeman Effect.
B)the Doppler Effect.
C)the selection effect.
D)the greenhouse effect.
E)adaptive optics.

Question 45

The Solar and Heliospheric Observatory (SOHO)is positioned:

A)in a geosynchronous orbit around the Earth.
B)in near-Earth orbit.
C)about 1.5 million kilometers from Earth at the L1 Lagrangian Point.
D)on the far side of the Sun at the L3 Langrangian Point.
E)on the far side of the Moon.

Question 46

A loop of gas following the magnetic field lines between sunspots' poles is:

A)a flare.
B)a ray.
C)a coronal hole.
D)a prominence.
E)a coronal mass ejection.

Question 47

The percentage (by number of atoms)of the Sun that is hydrogen is about:

A)91%.
B)71%.
C)27%.
D)9%.
E)less than 1%.

Question 48

From where does most of the solar wind flow?

A)granules
B)sunspots
C)flares
D)prominences
E)coronal holes

Question 49

Visible sunspots lie in the:

A)chromosphere.
B)transition zone.
C)corona.
D)radiative zone.
E)granulation in the photosphere.

Question 50

As the Sun rotates, an individual sunspot can be tracked across its face. From eastern towestern limb, this takes about:

A)12 hours.
B)a week.
C)2 weeks.
D)a month.
E)5.5 years.

Question 51

The percentage (by mass)of the Sun that is helium is about:

A)91%.
B)71%.
C)27%.
D)9%.
E)less than 1%.

Question 52

The pattern of rising hot gas cells all over the photosphere is called:

A)filaments.
B)granulation.
C)sunspots.
D)convective projections.
E)prominences.

Question 53

What is the size of a typical granule or convection cell seen in the photosphere?

A)10,000 km
B)1,000 km
C)100 km
D)10 km
E)1 km

Question 54

What two energy transport mechanisms, in order from outside the core to the surface, arefound in the Sun?

A)convection, conduction
B)radiative diffusion, convection
C)conduction, radiative diffusion
D)radiative diffusion, conduction
E)conduction, convection

Question 55

How long does the sunspot cycle last, on average?

A)between 25 and 35 days
B)365.25 days
C)about 7 years
D)about 11 years
E)about 76 years

Question 56

What is it about the Sun's corona that astronomers don't understand?

A)No one knows why that part of the Sun's atmosphere does not drift away into space.
B)During total solar eclipses, the corona sometimes disappears from view.
C)The corona seems to absorb 2/3 of the neutrinos that pass through it.
D)The corona is much hotter than layers of the Sun that are closer to the solar interior.
E)The Sun's corona extends to the outer reaches of the solar system.

Question 57

Large circulation patterns in the Sun, dubbed "Conveyor Belts," that transport material fromthe equator to the poles, then back to the equator at a depth of 300,000 km, take how long tocomplete a cycle?

A)less than a day
B)a few years
C)a few decades
D)a few centuries
E)tens of millions of years, comparable to the convection cycle in Earth's mantle

Question 58

Studies by the Global Oscillations Network Group, along with satellite observations,indicate:

A)that the standard solar model requires substantial modification.
B)that all stars show the same kind of vibrations that our Sun does.
C)that there is an unknown energy transport mechanism in the Sun.
D)that there is less convection in the Sun than predicted by the standard solar model.
E)that the standard solar model accurately models the observed solar vibrations.

Question 59

The above diagram indicates that:

A)the Sun is hottest somewhere between its surface and its core.
B)the Sun is coolest somewhere between its surface and its core.
C)the Sun is hotter at its surface than at its core.
D)the Sun is hotter at its core than at its surface.
E)the Sun has about the same temperature throughout its interior.

Question 60

When we glimpse the chromosphere at the start and end of totality, its color is:

A)green (the famous flash).
B)yellow, like the photosphere below it.
C)red, due to ionized hydrogen at lower pressure.
D)blue, due to the ionization of nitrogen by the magnetic fields.
E)white from the moonlight.

Question 61

On the Sun, what takes approximately 22 years to happen?

A)The Sun takes that time to rotate on its axis.
B)The complete sunspot cycle, including magnetic field reversals.
C)Solar vibrations begin every 22 years.
D)Solar activity goes from its maximum to minimum.
E)The corona reaches its maximum temperature and ejects gas every 22 years.

Question 62

Sunspots:

A)are always found close to the Sun's poles.
B)come in pairs, representing the north and south magnetic fields.
C)were most numerous during the Maunder Minimum.
D)travel over the surface of the Sun from pole to pole.
E)are relatively constant in number every year.

Question 63

How would sunspots appear if you could magically remove them from the Sun?

A)They would appear blue-white, like Sirius but brighter.
B)Because sunspots are dark spots, they would be invisible against the blackness of space.
C)They would shine bright orange in color, like Arcturus.
D)They would not appear any differently than on the surface of the Sun.
E)They would shine only with reflected sunlight, appearing similar to Venus.

Question 64

The Sun's magnetic field is measured by measuring:

A)the shift of spectral lines.
B)the temperature of the Sun.
C)the solar wind.
D)the splitting of spectral lines.
E)the spectral parallax.

Question 65

The most striking example of solar variability was:

A)the Dust Bowl drought of the 1930s.
B)the Maunder Minimum from 1645-1715.
C)the Sporer Minimum that doomed the Anasazi.
D)the fall of Rome.
E)Joseph's seven lean years in the Old Testament.

Question 66

Which of the following is NOT a property of neutrinos?

A)can change forms in the eight minutes from the Sun's core to us
B)almost massless
C)can travel very close to the speed of light
D)neutral in charge
E)cannot interact at all with normal matter

Question 67

In the proton-proton cycle, the positron is:

A)massless.
B)a spin conservation particle.
C)an anti-electron.
D)the chief means energy reaches the photosphere.
E)intermediate between the proton and neutron in mass.

Question 68

During a period of high solar activity, the corona:

A)disappears.
B)is more irregular.
C)cools almost to the temperature of the photosphere.
D)becomes smooth and even.
E)shrinks to half its normal size.

Question 69

While observing the Sun, you note a large number of sunspots. What can you conclude?

A)The Sun is less luminous than usual.
B)This is a period of low solar activity.
C)Earth's climate will be unusually cold.
D)The Sun's rotation is slower than average.
E)There are likely to be an above average number of flares and prominences.

Question 70

The critical temperature the core must reach for a star to shine by fusion is:

A)5,800 K.
B)11,000 K.
C)127,000 K.
D)10 million K.
E)100 million K.

Question 71

Sunspots are dark splotches on the Sun. Which statement is true?

A)They are hotter than the surrounding areas of the Sun.
B)They are extremely cold objects, as cold as Pluto.
C)They are extremely hot, but cooler than the surrounding areas of the Sun.
D)They are solid bodies floating on the surface of the Sun.
E)They are associated with areas of very low magnetic fields.

Question 72

Suppose a large flare is detected optically. How long until radio interference arrives?

A)simultaneously
B)8.5 minutes later
C)about 12 hours
D)about 4 days
E)no relation between the two

Question 73

The polarity of sunspot magnetic fields:

A)reverses every 22 years.
B)reverses every 11 years.
C)is consistent for all sunspots in the same hemisphere.
D)is unrelated between different sunspots.
E)changes the color of sunspots.

Question 74

In the proton-proton cycle, the helium atom and neutrino have less mass than the originalhydrogen. What happens to the "lost" mass?

A)It is recycled back into hydrogen.
B)It is ejected into space.
C)It is converted to energy.
D)It is transformed into electrons.
E)Conservation of mass dictates no mass can be lost.

Question 75

The solar winds blow outward from:

A)sunspots.
B)flares.
C)the entire photosphere.
D)coronal holes.
E)the Sun's poles only.

Question 76

Loops of glowing hydrogen seen hanging over the solar limb during totality are:

A)solar rainbows.
B)haloes.
C)prominences.
D)filaments.
E)flares.

Question 77

Which of these are NOT associated with the active Sun?

A)sunspots
B)prominences
C)granulation
D)flares
E)aurora

Question 78

There appears to be a correlation between the 22-year solar cycle and:

A)droughts in North America.
B)asteroid impacts on Earth.
C)change of which political party has the majority in the U.S. Congress.
D)the length of Mercury's day.
E)the length of Saturn's year.

Question 79

The primary source of the Sun's energy is:

A)oxidation of carbon in the core.
B)gravitational collapse of the helium coreward.
C)dark energy.
D)the strong force fusing hydrogen into helium.
E)the weak force creating energy from uranium decay.

Question 80

The number of sunspots and their activity peak about every:

A)36 days.
B)6 months.
C)year.
D)11 years.
E)76 years.