Test 2 Homework Answers (Creating)

Granulation is caused by:

a. sunspots

b. rising and sinking gases below the photosphere

c. shock waves in the corona

d. the solar wind flowing away from the corona

e. heading in the chromosphere

b. rising and sinking gases below the photosphere

Most of the visible light we see coming from the Sun originates from the:

a. chromosphere

b. photosphere

c. corona

d. sunspots

e. magnetic field

b. photosphere

The _____ coincides with the period known as the “little ice age” of Europe and North America. This provides one piece of evidence that suggests a link between solar activity and the amount of solar energy Earth receives.

a. Maunder sunspot minimum

b. Babcock sunspot model

c. coronal hole

d. Coulomb barrier

e. weak solar force

a. Maunder sunspot minimum

_____ occur about 130 km above Earth’s surface near the polar regions when energy in the solar wind guided by Earth’s magnetic field excites gases in the upper atmosphere.

a. coronas

b. flares

c. auroras

d. coronal holes

e. nuclear fission

c. auroras

Astronomers can use _____ to measure magnetic fields on the Sun.

a. helioseismology

b. perhloroethylene (C₂Cl₄)

c. neutrino detectors

d. a magnetic carpet

e. the Zeeman effect

e. the Zeeman effect

Sunspots are known to be magnetic phenomena because:

a. Doppler shifts in spectral lines are observed

b. the Zeeman effect is observed in sunspots

c. collisional broadening is observed in spectral lines

d. infrared observations indicate that the sunspots are cooler than their surroundings

e. observations during eclipses reveal a very extensive photosphere

b. the Zeeman effect is observed in sunspots

One sees differences in _____ depending on the time in the sunspot cycle.

I. the latitude at which most sunspots occur

II. the number of sunspots that are visible

III. the rotation rate of the Sun’s equator

IV. the magnetic polarity of the sunspot pair members in a hemisphere

a. I & II

b. I & IV

c. II & III

d. I, II, & III

e. I, II, & IV

e. I, II, & IV

Sunspots are dark because:

a. regions of the photosphere are obscured by material in the chromosphere

b. shock waves move through the photosphere

c. the Sun rotates differentially

d. they are cooler regions than the photosphere

e. they radiate their energy into space faster than the rest of the photosphere

d. they are cooler regions than the photosphere

A recent sunspot maximum occurred in 2013. What is the year of the sunspot maximum that immediately follows the 2013 maximum if the solar cycle continues?

a. 2017

b. 2019

c. 2022

d. 2024

e. The last cycle started a Maunder minimum and the next maximum cannot be predicted

d. 2024

A _____ is believed to occur when energy, stored in a twist in the solar magnetic field above a sunspot, is suddenly released.

a. solar flare

b. supergranule

c. spicule

d. coronal hole

e. none of the others

a. solar flare

The proton-proton chain needs high temperature because:

a. of the ground state energy of the hydrogen atom

b. of the presence of helium atoms

c. the protons must overcome the Coulomb barrier

d. of the need for density

e. the neutrinos carry more energy away than the reaction produces

c. the protons must overcome the Coulomb barrier

Why is the temperature at the region of a sunspot cooler than the photosphere?

a. They are holes in the photosphere that reveal the lower temperature gases in the deeper layers

b. They represent points where streams of cool gas from the corona lower the temperature in those regions of the photosphere

c. Powerful magnetic fields in the sunspots act upon the atoms of the photosphere to prevent them from emitting light

d. Powerful magnetic fields inhibit the convective flow of the gases of the photosphere downward, allowing them to cool for longer than would normally be permitted

d. Powerful magnetic fields inhibit the convective flow of the gases of the photosphere downward, allowing them to cool for longer than would normally be permitted

Sunspots occur in _____ with the leading spot and the trailing spot having _____ magnetic polarity.

a. singles, same

b. pairs, opposite

c. singles, opposite

d. pairs, same

e. none of the others

b. pairs, opposite

Most of the energy emitted by the Sun is generated in the:

a. corona

b. photosphere

c. chromosphere

d. core

d. core

Fusion is promoted in the core of the Sun by the _____ there.

a. low temperature and low density

b. high temperature and high density

c. low temperature and high density

d. high temperature and low density

b. high temperature and high density

______ of hydrogen atom nuclei in the core replace the heat the Sun _____ to keep it in equilibrium.

a. Nuclear fusion reactions; loses into space

b. Nuclear fusion reactions; gains from empty space

c. Chemical reactions; loses into space

d. Chemical reactions; gains from empty space

e. Nuclear fission; loses into space

a. Nuclear fusion reactions; loses into space

A neutrino is _____.

a. a photon of light

b. a positively charged particle

c. a subatomic particle

d. a negatively charged particle

c. a subatomic particle

The associated picture shows the Sun’s change in temperature with elevation into the Sun’s atmospheric layers. The region from 10,000-70,000 K is known as the _____.

a. photosphere

b. chromosphere

c. corona

d. transition zone

d. transition zone

The associated picture shows a prominence mostly in the _____ atmospheric layer of the Sun. Because of the far-ultraviolet (FUV) image, we know the _____ layer of the Sun’s atmosphere is shown.

a. chromospheric, chromospheric

b. photospheric, photospheric

c. corona, corona

d. corona, chromospheric

d. corona, chromospheric

_____ is to the Sun as _____ is to Earth.

a. asteroseismology, geology

b. helioseismology, seismology

c. seismology, volcanology

d. astrology, astrobiology

b. helioseismology, seismology

_____ has the most tightly bound nucleus.

a. Uranium

b. Iron

c. Helium

d. Hydrogen

b. Iron

The centers of granules:

a. are hot material rising to the photosphere from below

b. are cool material falling from the photosphere to the regions below

c. are fainter and hotter than their surroundings

d. are brighter and cooler than their surroundings

e. show strong Zeeman effects

a. are hot material rising to the photosphere from below

Parallax would be easier to measure if:

a. Earth’s orbit was larger.

b. The stars were farther away.

c. Earth moved faster along its orbit.

d. Earth’s orbit was larger, the stars were further away, and Earth moved faster along its orbit.

e. None of the other choices are correct.

a. Earth’s orbit was larger.

Absolute visual magnitude is:

a. The apparent magnitude of a star observed from Earth.

b. The luminosity of a star observed from a distance of 1,000 pc.

c. The apparent magnitude of a star observed from a distance of 10 pc.

d. The luminosity of a star observed from Earth.

e. The apparent magnitude of a star observed from a distance of 10 pc and the luminosity of a star observed from Earth.

c. The apparent magnitude of a star observed from a distance of 10 pc.

A star's luminosity depends only on the star's:

a. distance and diameter.

b. temperature and distance.

c. distance.

d. temperature and diameter.

e. apparent magnitude.

d. temperature and diameter.

In an H-R diagram, stars with the smallest radius are found in the _________ of the diagram.

a. center

b. upper left corner

c. upper right corner

d. lower left corner

e. lower right corner

d. lower left corner

In the H-R diagram, roughly 80 percent of all stars are:

a. in the giant region.

b. in the supergiant region.

c. among the B stars.

d. among the G stars.

e. on the main sequence.

e. on the main sequence.

Red giant stars are:

I. More luminous than the Sun

II. Larger in diameter than the Sun.

III. Cooler than B stars.

IV. Located above the main-sequence stars in the H-R diagram.

a. I & II

b. II & IV

c. II, III, & IV

d. II, III, & IV

e. I, II, III, & IV

e. I, II, III, & IV

Compared with the spectral lines in the solar spectrum, lines in a supergiant star’s spectrum are:

a. narrower.

b. broader.

c. weaker.

d. stronger.

e. broader and weaker.

a. narrower.

The star named Sheet is of M2 II spectral type and luminosity class. Based on this information, which of the following are true?

I. Sheet has a surface temperature less than the Sun.

II. Sheet has a diameter that is greater than that of the Sun.

III. Sheet is more luminous than the Sun.

IV. Sheet is located near the upper let-hand corner in the H-R diagram.

a. I & II

b. II & IV

c. II, III, & IV

d. I, II, & III

e. I, II, III, & IV

d. I, II, & III

The star named Circini has the spectral type and luminosity class of O 8.5 V. Based on this information, which of the following are true?

I. Circini has a surface temperature less than the Sun.

II. Circini has a diameter that is greater than that of the Sun.

III. Circini is more luminous than the Sun.

IV. Circini is located near the upper left-hand corner in the H-R diagram.

a. I & II

b. II & IV

c. II, III, & IV

d. I, II, & III

e. I, II, III, & IV

c. II, III, & IV

In a binary system, the more massive star:

a. is at the center of mass.

b. is farthest from the center of mass.

c. is nearest the center of mass.

d. follows the largest orbit.

e. shows a larger Doppler shift in its spectral lines.

c. is nearest the center of mass.

Use the H-R diagram to answer this question. Which star is. most like the Sun?

a. Alnilam

b. Antares

c. Arcturus

d. HR 5337

e. Sirius B

d. HR 5337

Use the H-R diagram to answer this question. Which star has the greatest surface temperature?

a. Alnilam

b. Antares

c. Arcturus

d. HR 5337

e. Sirius B

a. Alnilam

If we can solve the orbital motion of an eclipsing binary, we can find:

a. The mass of each star.

b. The diameter of each star.

c. The distance to the binary.

d. All of the other choices.

e. The mass of each star and the diameter of each star.

e. The mass of each star and the diameter of each star.

Which of the following kinds of stars best obey the mass-luminosity relation?

a. Main-sequence stars

b. Giant stars

c. Supergiant stars

d. White dwarfs

e. All of the other choices are correct.

a. Main-sequence stars

Which of the following kind of stars is the most dense?

a. A supergiant star

b. A main sequence star

c. A giant star

d. A white dwarf

e. The Sun

d. A white dwarf

Stars on the main sequence with the greatest mass

a. are spectral type M stars.

b. are spectral type O stars.

c. are located at the bottom of the main sequence in the H-R diagram.

d. have masses very similar to the Sun.

e. are spectral type O stars and are located at the bottom of the main sequence in the H-R diagram.

b. are spectral type O stars.

The total mass of a binary system can be calculated from":

a. The ratio of the. angular separation from the center of mass of each of the stars.

b. The distance of the binary and its radial velocity.

c. The semi major axis and period of the orbit.

d. The radial velocities the two stars.

e. The time required for the smaller star to eclipse the larger star.

c. The semi major axis and period of the orbit.

In the light curve, what is the period of the eclipsing binary?

a. 5 days

b. 32.5 days

c. 7.5 days

d. 42.5 days

e. 50 days

b. 32.5 days

From the data given, which star in the table would appear the faintest in the night sky?

a. 65 Tau

b. HR 4621

c. α Pic

d. 58 Ori

e. HR 2491

a. 65 Tau

From the data given, which star in the table has the greatest surface temperature?

a. 65 Tau

b. HR 4621

c. α Pic

d. 58 Ori

e. HR 2491

b. HR 4621

From the data given, which star in the table has the greatest diameter?

a. 65 Tau

b. HR 4621

c. α Pic

d. 58 Ori

e. HR 2491

d. 58 Ori

Which stars always have large positive absolute magnitude?

a. Stars of high luminosity

b. Stars of low luminosity

c. Nearby stars

d. Distant stars

e. Not enough information given

b. Stars of low luminosity

Why don’t we see hydrogen Balmer lines in the spectra of stars with temperatures of 3,200 K?

a. There is no hydrogen in stars this cool.

b. The stars are hot enough that most of the hydrogen is ionized and the atoms cannot absorb energy.

c. These stars are so cool that nearly all of the hydrogen atoms are in the ground state.

d. Stars of this temperature are too cool to produce an absorption spectrum.

e. Stars of this temperature are too hot to produce an absorption spectrum.

c. These stars are so cool that nearly all of the hydrogen atoms are in the ground state.

Why don’t we see hydrogen Balmer lines in the spectra of stars with temperatures of 45,000 K?

a. There is no hydrogen in stars this cool.

b. The stars are hot enough that most of the hydrogen is ionized and the atoms cannot absorb energy.

c. These stars are so cool that nearly all of the hydrogen atoms are in the ground state.

d. Stars of this temperature are too cool to produce an absorption spectrum.

e. Stars of this temperature are too hot to produce an absorption spectrum.

b. The stars are hot enough that most of the hydrogen is ionized and the atoms cannot absorb energy.

Continue with

Chapters 9 and 10