Question 1

As you move closer to a star,which two of its properties change?

Accepted Answer

A)  luminosity and absolute magnitude 
B)  Luminosity and absolute magnitude 
C)  absolute magnitude and brightness 
D)  apparent magnitude and brightness 
A)  luminosity and absolute magnitude 
B)  Luminosity and absolute magnitude 
C)  absolute magnitude and brightness 
D)  apparent magnitude and brightness

Question 2

How bright (in absolute magnitude)are the intrinsically faintest stars in the universe?

Accepted Answer

A)  +1 
B)  +17 
C)  -10 
D)  0 
A)  +1 
B)  +17 
C)  -10 
D)  0

Question 3

What characterizes A-type stars?

Accepted Answer

A)  They have the strongest hydrogen lines. 
B)  They have the strongest calcium lines. 
C)  They are the hottest stars. 
D)  They are the largest stars. 
A)  They have the strongest hydrogen lines. 
B)  They have the strongest calcium lines. 
C)  They are the hottest stars. 
D)  They are the largest stars.

Question 4

Which sequence of stellar spectral classifications is in the CORRECT order of increasing temperature?

Accepted Answer

A)  K, M, G, F, A, B, O 
B)  A, B, F, G, K, M, O 
C)  M, K, G, F, A, B, O 
D)  O, B, A, F, G, K, M 
A)  K, M, G, F, A, B, O 
B)  A, B, F, G, K, M, O 
C)  M, K, G, F, A, B, O 
D)  O, B, A, F, G, K, M

Question 5

A star of apparent magnitude +4.7 appears _____ than a star of apparent magnitude +4.8.

Accepted Answer

A)  brighter 
B)  either brighter or fainter, depending on the distance to the stars, 
C)  farther away 
D)  fainter 
A)  brighter 
B)  either brighter or fainter, depending on the distance to the stars, 
C)  farther away 
D)  fainter

Question 6

Why is there a limited range of stellar surface temperatures around 10,000 K at which neutral hydrogen gas absorbs visible light in the Balmer series?

Accepted Answer

A)  There must be electrons at the n = 3 energy level for Balmer absorption to occur. If the gas is too cold, electrons are only in the n = 1 and 2 levels; if the gas is too hot, the gas is ionized and no electrons are left in the hydrogen atoms. 
B)  Electrons in hydrogen have to be at the n = 2 energy level to produce absorption in this series. If the gas is too cold, most atoms are in the n = 1 state; if it is too hot, most atoms are ionized. 
C)  Electrons must be in the ground state n = 1 to undergo Balmer absorption. If the gas is too cold, electrons cannot be excited from this level; if the gas is too hot, there are no electrons left in the n = 1 level. 
D)  There must be sufficient continuum radiation from the stellar surface in the visible region to be absorbed by the hydrogen gas. 
A)  There must be electrons at the n = 3 energy level for Balmer absorption to occur. If the gas is too cold, electrons are only in the n = 1 and 2 levels; if the gas is too hot, the gas is ionized and no electrons are left in the hydrogen atoms. 
B)  Electrons in hydrogen have to be at the n = 2 energy level to produce absorption in this series. If the gas is too cold, most atoms are in the n = 1 state; if it is too hot, most atoms are ionized. 
C)  Electrons must be in the ground state n = 1 to undergo Balmer absorption. If the gas is too cold, electrons cannot be excited from this level; if the gas is too hot, there are no electrons left in the n = 1 level. 
D)  There must be sufficient continuum radiation from the stellar surface in the visible region to be absorbed by the hydrogen gas.

Question 7

Absolute magnitude is defined as the apparent magnitude that a star would have if:

Accepted Answer

A)  all the energy from the star were concentrated in the visual region. 
B)  it were located at exactly 10 ly from Earth. 
C)  it were located at exactly 10 pc from Earth. 
D)  it were located at exactly 10 AU from Earth. 
A)  all the energy from the star were concentrated in the visual region. 
B)  it were located at exactly 10 ly from Earth. 
C)  it were located at exactly 10 pc from Earth. 
D)  it were located at exactly 10 AU from Earth.

Question 8

How far out into space can distances be determined using telescopes on Earth if stellar parallax values no smaller than 0.01 arcsec can be measured?

Accepted Answer

A)  10 pc 
B)  100 pc 
C)  500 pc 
D)  2000 pc 
A)  10 pc 
B)  100 pc 
C)  500 pc 
D)  2000 pc

Question 9

A particular star has an apparent magnitude of +12 and an absolute magnitude of +5.According to the equation in Discovery 10-2 in Comins,Discovering the Essential Universe,6th ed.,what is the distance to this star?

Accepted Answer

A)  125 pc 
B)  250 pc 
C)  125 ly 
D)  250 ly 
A)  125 pc 
B)  250 pc 
C)  125 ly 
D)  250 ly

Question 10

The Sun's absolute magnitude is about +5.The brightest stars in our sky have absolute magnitudes of about -10.What is the luminosity of these stars compared with that of the Sun,assuming that they have similar spectral light distributions?

Accepted Answer

A)  1 million times less 
B)  5 times less 
C)  1 million times greater 
D)  15 times greater 
A)  1 million times less 
B)  5 times less 
C)  1 million times greater 
D)  15 times greater

Question 11

Which possible factor MOST seriously limits the accuracy of spectroscopic parallax?

Accepted Answer

A)  Stars of the same spectral luminosity class can have a range of temperatures. 
B)  It is difficult to accurately measure angular displacement for distant stars. 
C)  Stars of the same spectral luminosity class can have a range of absolute magnitudes. 
D)  It is not possible to accurately classify the spectral luminosity of even a nearby star. 
A)  Stars of the same spectral luminosity class can have a range of temperatures. 
B)  It is difficult to accurately measure angular displacement for distant stars. 
C)  Stars of the same spectral luminosity class can have a range of absolute magnitudes. 
D)  It is not possible to accurately classify the spectral luminosity of even a nearby star.

Question 12

Stars of spectral type O,the hottest blue-white stars,have spectra characterized by:

Accepted Answer

A)  the strongest hydrogen lines of any spectral type. 
B)  spectra of complex molecules. 
C)  very few spectral lines. 
D)  very intense spectral lines all across the spectrum. 
A)  the strongest hydrogen lines of any spectral type. 
B)  spectra of complex molecules. 
C)  very few spectral lines. 
D)  very intense spectral lines all across the spectrum.

Question 13

As you move along the main sequence,the masses of stars:

Accepted Answer

A)  show no obvious relationship to temperature. 
B)  increase with increasing temperature. 
C)  decrease with increasing temperature. 
D)  remain relatively constant. 
A)  show no obvious relationship to temperature. 
B)  increase with increasing temperature. 
C)  decrease with increasing temperature. 
D)  remain relatively constant.

Question 14

A particular star has an absolute magnitude of 0 and a spectral class similar to that of the Sun.Using Figure 10-10 of Comins,Discovering the Essential Universe,6th ed.,how would this star be classified?

Accepted Answer

A)  G2 V 
B)  G-type white dwarf 
C)  G2 I 
D)  G2 III 
A)  G2 V 
B)  G-type white dwarf 
C)  G2 I 
D)  G2 III

Question 15

Use the absorption line strengths shown in Figure 10-5 and Table 10-1 of Comins,Discovering the Essential Universe,6th ed.,to determine the spectral class of a star with the following absorption lines in its spectrum: H lines moderately strong; He I lines present; no Ca II,Fe II,or He II lines.

Accepted Answer

A)  M 
B)  B 
C)  F 
D)  A 
A)  M 
B)  B 
C)  F 
D)  A

Question 16

The spectrum of a star shows the following absorption line characteristics: very strong H,weaker Mg II and Si II,and no He I or Ca II lines.Classify the spectrum of this star,using the absorption line strengths in the spectra of stars as shown in Figure 10-5 and Table 10-1 of Comins,Discovering the Essential Universe,6th ed.

Accepted Answer

A)  B 
B)  G 
C)  K 
D)  A 
A)  B 
B)  G 
C)  K 
D)  A

Question 17

When two stars of unequal mass orbit each other under their mutual gravitational attraction,where is the center of mass of the system located?

Accepted Answer

A)  point halfway between the centers of the stars 
B)  point between the stars, closer to the less massive star 
C)  center of the more massive star 
D)  point between the two stars, closer to the more massive star 
A)  point halfway between the centers of the stars 
B)  point between the stars, closer to the less massive star 
C)  center of the more massive star 
D)  point between the two stars, closer to the more massive star

Question 18

The surface temperature of a nearby star can BEST be determined from spectral classification by examining the:

Accepted Answer

A)  pattern of spectral absorption lines from various atoms. 
B)  relative intensities of light measured through different photometric filters. 
C)  peak wavelength of the star's continuous blackbody spectrum. 
D)  pattern of emission lines that are on the star's spectrum. 
A)  pattern of spectral absorption lines from various atoms. 
B)  relative intensities of light measured through different photometric filters. 
C)  peak wavelength of the star's continuous blackbody spectrum. 
D)  pattern of emission lines that are on the star's spectrum.

Question 19

In the Hertzsprung-Russell diagram in Figure 10-7 of Comins,Discovering the Essential Universe,6th ed.,which list is the CORRECT sequence of stars in order of increasing intrinsic brightness?

Accepted Answer

A)  Deneb, the Sun, Sirius B, Procyon B 
B)  Sirius B, Deneb, Procyon B, the Sun 
C)  Sun, Procyon B, Deneb, Sirius B 
D)  Procyon B, Sirius B, the Sun, Deneb 
A)  Deneb, the Sun, Sirius B, Procyon B 
B)  Sirius B, Deneb, Procyon B, the Sun 
C)  Sun, Procyon B, Deneb, Sirius B 
D)  Procyon B, Sirius B, the Sun, Deneb

Question 20

The star Alderamin has an apparent magnitude of 2.4 and an absolute magnitude of 1.4.From this information (assuming that the starlight has not been dimmed by interstellar clouds),we can say for sure that Alderamin is _____ away.

Accepted Answer

A)  less than 10 pc 
B)  less than 10 ly 
C)  more than 10 ly 
D)  more than 10 pc 
A)  less than 10 pc 
B)  less than 10 ly 
C)  more than 10 ly 
D)  more than 10 pc

As you move closer to a star,which two of its properties change?

How bright (in absolute magnitude)are the intrinsically faintest stars in the universe?

What characterizes A-type stars?

Which sequence of stellar spectral classifications is in the CORRECT order of increasing temperature?

A star of apparent magnitude +4.7 appears _____ than a star of apparent magnitude +4.8.

Why is there a limited range of stellar surface temperatures around 10,000 K at which neutral hydrogen gas absorbs visible light in the Balmer series?

Absolute magnitude is defined as the apparent magnitude that a star would have if:

How far out into space can distances be determined using telescopes on Earth if stellar parallax values no smaller than 0.01 arcsec can be measured?

A particular star has an apparent magnitude of +12 and an absolute magnitude of +5.According to the equation in Discovery 10-2 in Comins,Discovering the Essential Universe,6th ed.,what is the distance to this star?

The Sun's absolute magnitude is about +5.The brightest stars in our sky have absolute magnitudes of about -10.What is the luminosity of these stars compared with that of the Sun,assuming that they have similar spectral light distributions?

Which possible factor MOST seriously limits the accuracy of spectroscopic parallax?

Stars of spectral type O,the hottest blue-white stars,have spectra characterized by:

As you move along the main sequence,the masses of stars:

A particular star has an absolute magnitude of 0 and a spectral class similar to that of the Sun.Using Figure 10-10 of Comins,Discovering the Essential Universe,6th ed.,how would this star be classified?

Use the absorption line strengths shown in Figure 10-5 and Table 10-1 of Comins,Discovering the Essential Universe,6th ed.,to determine the spectral class of a star with the following absorption lines in its spectrum: H lines moderately strong; He I lines present; no Ca II,Fe II,or He II lines.

When two stars of unequal mass orbit each other under their mutual gravitational attraction,where is the center of mass of the system located?

The surface temperature of a nearby star can BEST be determined from spectral classification by examining the:

In the Hertzsprung-Russell diagram in Figure 10-7 of Comins,Discovering the Essential Universe,6th ed.,which list is the CORRECT sequence of stars in order of increasing intrinsic brightness?

The star Alderamin has an apparent magnitude of 2.4 and an absolute magnitude of 1.4.From this information (assuming that the starlight has not been dimmed by interstellar clouds),we can say for sure that Alderamin is _____ away.

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters

Exam 10: Characterizing Stars

As you move closer to a star,which two of its properties change?

How bright (in absolute magnitude)are the intrinsically faintest stars in the universe?

What characterizes A-type stars?

Which sequence of stellar spectral classifications is in the CORRECT order of increasing temperature?

A star of apparent magnitude +4.7 appears _____ than a star of apparent magnitude +4.8.

Why is there a limited range of stellar surface temperatures around 10,000 K at which neutral hydrogen gas absorbs visible light in the Balmer series?

Absolute magnitude is defined as the apparent magnitude that a star would have if:

How far out into space can distances be determined using telescopes on Earth if stellar parallax values no smaller than 0.01 arcsec can be measured?

A particular star has an apparent magnitude of +12 and an absolute magnitude of +5.According to the equation in Discovery 10-2 in Comins,Discovering the Essential Universe,6th ed.,what is the distance to this star?

The Sun's absolute magnitude is about +5.The brightest stars in our sky have absolute magnitudes of about -10.What is the luminosity of these stars compared with that of the Sun,assuming that they have similar spectral light distributions?

Which possible factor MOST seriously limits the accuracy of spectroscopic parallax?

Stars of spectral type O,the hottest blue-white stars,have spectra characterized by:

As you move along the main sequence,the masses of stars:

A particular star has an absolute magnitude of 0 and a spectral class similar to that of the Sun.Using Figure 10-10 of Comins,Discovering the Essential Universe,6th ed.,how would this star be classified?

Use the absorption line strengths shown in Figure 10-5 and Table 10-1 of Comins,Discovering the Essential Universe,6th ed.,to determine the spectral class of a star with the following absorption lines in its spectrum: H lines moderately strong; He I lines present; no Ca II,Fe II,or He II lines.

When two stars of unequal mass orbit each other under their mutual gravitational attraction,where is the center of mass of the system located?

The surface temperature of a nearby star can BEST be determined from spectral classification by examining the:

In the Hertzsprung-Russell diagram in Figure 10-7 of Comins,Discovering the Essential Universe,6th ed.,which list is the CORRECT sequence of stars in order of increasing intrinsic brightness?

The star Alderamin has an apparent magnitude of 2.4 and an absolute magnitude of 1.4.From this information (assuming that the starlight has not been dimmed by interstellar clouds),we can say for sure that Alderamin is _____ away.

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters