Question 1

What is a Cepheid variable star?

Accepted Answer

A)  one of several classes of stars that pulsate randomly in brightness 
B)  a low-mass, horizontal-branch star that pulsates regularly in brightness 
C)  a star that normally remains constant in brightness but occasionally flares up in brightness by several magnitudes 
D)  a high-mass star that pulsates regularly in brightness 
A)  one of several classes of stars that pulsate randomly in brightness 
B)  a low-mass, horizontal-branch star that pulsates regularly in brightness 
C)  a star that normally remains constant in brightness but occasionally flares up in brightness by several magnitudes 
D)  a high-mass star that pulsates regularly in brightness

Question 2

Approximately what fraction of its main-sequence lifetime has the Sun completed at the present time (see Table 11-2,Comins,Discovering the Essential Universe,6th ed.)?

Accepted Answer

A)  about 1/4 
B)  less than 10% 
C)  about 1/2 
D)  about 3/4 
A)  about 1/4 
B)  less than 10% 
C)  about 1/2 
D)  about 3/4

Question 3

Which description characterizes the early stages of a red giant?

Accepted Answer

A)  a large, red star that is burning hydrogen into helium in its core 
B)  a protostar in the upper right of the Hertzsprung-Russell diagram 
C)  a large-emission nebula 
D)  a star that is burning hydrogen into helium in a shell around the core 
A)  a large, red star that is burning hydrogen into helium in its core 
B)  a protostar in the upper right of the Hertzsprung-Russell diagram 
C)  a large-emission nebula 
D)  a star that is burning hydrogen into helium in a shell around the core

Question 4

Which stars are metal-poor?

Accepted Answer

A)  open-cluster stars 
B)  very young stars 
C)  Population II stars 
D)  Population I stars 
A)  open-cluster stars 
B)  very young stars 
C)  Population II stars 
D)  Population I stars

Question 5

The characteristic of a globular cluster of stars is:

Accepted Answer

A)  hundreds of thousands of members, all very old and generally metal-poor. 
B)  a few dozen members, the remnant of a globular cluster of stars from which most of the members have escaped. 
C)  many thousands of members of different ages. 
D)  a few hundred members, often very young and still embedded in the gas and dust from which they were formed. 
A)  hundreds of thousands of members, all very old and generally metal-poor. 
B)  a few dozen members, the remnant of a globular cluster of stars from which most of the members have escaped. 
C)  many thousands of members of different ages. 
D)  a few hundred members, often very young and still embedded in the gas and dust from which they were formed.

Question 6

What is the difference between a Type I Cepheid (δ Cephei star)and a Type II Cepheid (W Virginis star)?

Accepted Answer

A)  Type I Cepheids are main-sequence stars, while Type II Cepheids are giant stars. 
B)  Type I Cepheids are short-period variables, while Type II Cepheids are long-period variables. 
C)  Only Type I Cepheids have a simple relationship between luminosity and period. 
D)  Type I Cepheids are brighter metal-rich stars, while Type II Cepheids are dimmer metal-poor stars. 
A)  Type I Cepheids are main-sequence stars, while Type II Cepheids are giant stars. 
B)  Type I Cepheids are short-period variables, while Type II Cepheids are long-period variables. 
C)  Only Type I Cepheids have a simple relationship between luminosity and period. 
D)  Type I Cepheids are brighter metal-rich stars, while Type II Cepheids are dimmer metal-poor stars.

Question 7

The shape of the cross-section of the Roche lobes around a close binary star system,taken through the centers of both stars,is:

Accepted Answer

A)  two unequal ellipses that touch at the center of the lobes. 
B)  a sphere centered on the center of mass of the star system. 
C)  an ellipse with a star at each focus. 
D)  a figure eight. 
A)  two unequal ellipses that touch at the center of the lobes. 
B)  a sphere centered on the center of mass of the star system. 
C)  an ellipse with a star at each focus. 
D)  a figure eight.

Question 8

The spiral galaxy in which we live is roughly 14 billion years old.Which statement about the stars that formed when our Galaxy was very young (say,during the first billion years)is TRUE? (See Table 11-2,Comins,Discovering the Essential Universe,6th ed.)

Accepted Answer

A)  No stars are still on the main sequence-in this time all stars have finished their lives. 
B)  All stars of less than 3/4 of the mass of the Sun are still on the main sequence. 
C)  All stars of more than 15 times the mass of the Sun are still on the main sequence. 
D)  All stars of 3 times the mass of the Sun are still on the main sequence. 
A)  No stars are still on the main sequence-in this time all stars have finished their lives. 
B)  All stars of less than 3/4 of the mass of the Sun are still on the main sequence. 
C)  All stars of more than 15 times the mass of the Sun are still on the main sequence. 
D)  All stars of 3 times the mass of the Sun are still on the main sequence.

Question 9

The mass of a particular interstellar giant molecular cloud is 2 million solar masses.Approximately what is the mass of the hydrogen in this cloud?

Accepted Answer

A)  40,000 solar masses 
B)  1 million solar masses 
C)  1.5 million solar masses 
D)  1.96 million solar masses 
A)  40,000 solar masses 
B)  1 million solar masses 
C)  1.5 million solar masses 
D)  1.96 million solar masses

Question 10

Which sequence CORRECTLY lists the objects in order of smallest to largest?

Accepted Answer

A)  giant molecular cloud, H II region, OB association 
B)  OB association, H II region, giant molecular cloud 
C)  OB association, giant molecular cloud, H II region 
D)  H II region, giant molecular cloud, OB association 
A)  giant molecular cloud, H II region, OB association 
B)  OB association, H II region, giant molecular cloud 
C)  OB association, giant molecular cloud, H II region 
D)  H II region, giant molecular cloud, OB association

Question 11

How is gas distributed in interstellar space?

Accepted Answer

A)  in clumps, concentrated in interstellar clouds 
B)  concentrated in narrow river-like streams of gas that extend across the Galaxy 
C)  uniformly distributed through space 
D)  concentrated around existing stars because of the stars' gravitational pull 
A)  in clumps, concentrated in interstellar clouds 
B)  concentrated in narrow river-like streams of gas that extend across the Galaxy 
C)  uniformly distributed through space 
D)  concentrated around existing stars because of the stars' gravitational pull

Question 12

Which range of electromagnetic radiation is useful for observing newborn protostars in their gas and dust nebulae?

Accepted Answer

A)  infrared 
B)  visible 
C)  highly penetrating X-ray 
D)  radio 
A)  infrared 
B)  visible 
C)  highly penetrating X-ray 
D)  radio

Question 13

The stars at the turnoff point in the Hertzsprung-Russell diagram of the Hyades star cluster have a luminosity of approximately 10 times that of the Sun,while those at the turnoff point in the cluster M41 have a luminosity of about 80 times that of the Sun.From this information,it can be said with certainty that the Hyades cluster:

Accepted Answer

A)  has more stars in it than the M41 cluster. 
B)  is younger than the M41 cluster. 
C)  is farther away than the M41 cluster. 
D)  is older than the M41 cluster. 
A)  has more stars in it than the M41 cluster. 
B)  is younger than the M41 cluster. 
C)  is farther away than the M41 cluster. 
D)  is older than the M41 cluster.

Question 14

When core helium burning begins in the Sun,the Sun will have a size (diameter)roughly equal to:

Accepted Answer

A)  half the size of Earth's orbit. 
B)  the size of Earth. 
C)  half its present size. 
D)  twice its present size. 
A)  half the size of Earth's orbit. 
B)  the size of Earth. 
C)  half its present size. 
D)  twice its present size.

Question 15

What is the typical mass of a giant molecular cloud?

Accepted Answer

A)  10 to 100 solar masses 
B)  1000 to 10,000 solar masses 
C)  100,000 to 1 million solar masses 
D)  10 million to 1 billion solar masses 
A)  10 to 100 solar masses 
B)  1000 to 10,000 solar masses 
C)  100,000 to 1 million solar masses 
D)  10 million to 1 billion solar masses

Question 16

Which mechanism is NOT considered to be a way in which star formation is triggered or started?

Accepted Answer

A)  collisions between interstellar clouds 
B)  heating of an interstellar cloud by radiation from embedded young stars 
C)  compression of an interstellar cloud by the shock waves from supernova explosion 
D)  compression of an interstellar cloud by the pressure of light from nearby stars 
A)  collisions between interstellar clouds 
B)  heating of an interstellar cloud by radiation from embedded young stars 
C)  compression of an interstellar cloud by the shock waves from supernova explosion 
D)  compression of an interstellar cloud by the pressure of light from nearby stars

Question 17

How long ago was the Sun a ZAMS star?

Accepted Answer

A)  12 billion years 
B)  6 billion years 
C)  60 million years 
D)  187 million years. 
A)  12 billion years 
B)  6 billion years 
C)  60 million years 
D)  187 million years.

Question 18

The mass of a particular giant molecular cloud in interstellar space is 2 million solar masses.What is the mass of the helium in this cloud?

Accepted Answer

A)  40,000 solar masses 
B)  1 million solar masses 
C)  200,000 solar masses 
D)  500,000 solar masses 
A)  40,000 solar masses 
B)  1 million solar masses 
C)  200,000 solar masses 
D)  500,000 solar masses

Question 19

The major source of energy in the pre-main-sequence life of the Sun was:

Accepted Answer

A)  nuclear fusion. 
B)  burning of carbon atoms. 
C)  gravitation. 
D)  nuclear fission. 
A)  nuclear fusion. 
B)  burning of carbon atoms. 
C)  gravitation. 
D)  nuclear fission.

Question 20

Where are protostars MOST likely to form?

Accepted Answer

A)  in emission nebulae 
B)  in reflection nebulae 
C)  in dark nebulae 
D)  in planetary nebulae 
A)  in emission nebulae 
B)  in reflection nebulae 
C)  in dark nebulae 
D)  in planetary nebulae

What is a Cepheid variable star?

Approximately what fraction of its main-sequence lifetime has the Sun completed at the present time (see Table 11-2,Comins,Discovering the Essential Universe,6th ed.)?

Which description characterizes the early stages of a red giant?

Which stars are metal-poor?

The characteristic of a globular cluster of stars is:

What is the difference between a Type I Cepheid (δ Cephei star)and a Type II Cepheid (W Virginis star)?

The shape of the cross-section of the Roche lobes around a close binary star system,taken through the centers of both stars,is:

The spiral galaxy in which we live is roughly 14 billion years old.Which statement about the stars that formed when our Galaxy was very young (say,during the first billion years)is TRUE? (See Table 11-2,Comins,Discovering the Essential Universe,6th ed.)

The mass of a particular interstellar giant molecular cloud is 2 million solar masses.Approximately what is the mass of the hydrogen in this cloud?

Which sequence CORRECTLY lists the objects in order of smallest to largest?

How is gas distributed in interstellar space?

Which range of electromagnetic radiation is useful for observing newborn protostars in their gas and dust nebulae?

When core helium burning begins in the Sun,the Sun will have a size (diameter)roughly equal to:

What is the typical mass of a giant molecular cloud?

Which mechanism is NOT considered to be a way in which star formation is triggered or started?

How long ago was the Sun a ZAMS star?

The mass of a particular giant molecular cloud in interstellar space is 2 million solar masses.What is the mass of the helium in this cloud?

The major source of energy in the pre-main-sequence life of the Sun was:

Where are protostars MOST likely to form?

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

Characterizing Stars

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters

Exam 11: The Lives of the Stars From Birth Through Middle Age

What is a Cepheid variable star?

Approximately what fraction of its main-sequence lifetime has the Sun completed at the present time (see Table 11-2,Comins,Discovering the Essential Universe,6th ed.)?

Which description characterizes the early stages of a red giant?

Which stars are metal-poor?

The characteristic of a globular cluster of stars is:

What is the difference between a Type I Cepheid (δ Cephei star)and a Type II Cepheid (W Virginis star)?

The shape of the cross-section of the Roche lobes around a close binary star system,taken through the centers of both stars,is:

The spiral galaxy in which we live is roughly 14 billion years old.Which statement about the stars that formed when our Galaxy was very young (say,during the first billion years)is TRUE? (See Table 11-2,Comins,Discovering the Essential Universe,6th ed.)

The mass of a particular interstellar giant molecular cloud is 2 million solar masses.Approximately what is the mass of the hydrogen in this cloud?

Which sequence CORRECTLY lists the objects in order of smallest to largest?

How is gas distributed in interstellar space?

Which range of electromagnetic radiation is useful for observing newborn protostars in their gas and dust nebulae?

When core helium burning begins in the Sun,the Sun will have a size (diameter)roughly equal to:

What is the typical mass of a giant molecular cloud?

Which mechanism is NOT considered to be a way in which star formation is triggered or started?

How long ago was the Sun a ZAMS star?

The mass of a particular giant molecular cloud in interstellar space is 2 million solar masses.What is the mass of the helium in this cloud?

The major source of energy in the pre-main-sequence life of the Sun was:

Where are protostars MOST likely to form?

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

Characterizing Stars

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters