Question 1

What is the SECOND most abundant element in the universe (after hydrogen)?

Accepted Answer

A)  helium 
B)  carbon 
C)  nitrogen 
D)  iron 
A)  helium 
B)  carbon 
C)  nitrogen 
D)  iron

Question 2

What event occurs at the end of the protostar stage of a star's life?

Accepted Answer

A)  The star explodes, forming a supernova remnant. 
B)  Gas is spun off from the star's equator, from which planets may form. 
C)  Nuclear reactions begin in the star's core, converting hydrogen into helium. 
D)  The star begins a long period of contraction in which gravitational energy is converted into heat. 
A)  The star explodes, forming a supernova remnant. 
B)  Gas is spun off from the star's equator, from which planets may form. 
C)  Nuclear reactions begin in the star's core, converting hydrogen into helium. 
D)  The star begins a long period of contraction in which gravitational energy is converted into heat.

Question 3

A main-sequence star is defined as a star:

Accepted Answer

A)  with a surface temperature equal to that of the Sun. 
B)  in which nuclear fusion reactions generate sufficient energy to oppose further condensation of the star. 
C)  whose age after birth is about 1 million years. 
D)  with a luminosity precisely equal to that of the Sun. 
A)  with a surface temperature equal to that of the Sun. 
B)  in which nuclear fusion reactions generate sufficient energy to oppose further condensation of the star. 
C)  whose age after birth is about 1 million years. 
D)  with a luminosity precisely equal to that of the Sun.

Question 4

The transfer of mass from the surface of one star onto the surface of another is MOST often observed in _____ binaries.

Accepted Answer

A)  detached 
B)  overcontact 
C)  contact 
D)  semidetached 
A)  detached 
B)  overcontact 
C)  contact 
D)  semidetached

Question 5

What rates of mass loss from red giant stars are typical?

Accepted Answer

A)  10-¹⁴ solar mass per year 
B)  10-³ solar mass per year 
C)  Red giant stars do not suffer mass loss. 
D)  10-⁷ solar mass per year 
A)  10-¹⁴ solar mass per year 
B)  10-³ solar mass per year 
C)  Red giant stars do not suffer mass loss. 
D)  10-⁷ solar mass per year

Question 6

What fraction of the mass of a typical interstellar cloud is helium?

Accepted Answer

A)  50% 
B)  2% 
C)  10% 
D)  25% 
A)  50% 
B)  2% 
C)  10% 
D)  25%

Question 7

What are the main general features that make clusters of stars useful to astronomers?

Accepted Answer

A)  The stars all have the same apparent magnitude, the same surface temperatures, and the same sizes. 
B)  The stars are all at the same distance from Earth, have the same surface temperature, and joined the cluster at various times. 
C)  The stars all have the same intrinsic brightness but differ in size and surface temperature. 
D)  The stars are at the same distance from Earth, were formed at approximately the same time, and were made from the same chemical mix. 
A)  The stars all have the same apparent magnitude, the same surface temperatures, and the same sizes. 
B)  The stars are all at the same distance from Earth, have the same surface temperature, and joined the cluster at various times. 
C)  The stars all have the same intrinsic brightness but differ in size and surface temperature. 
D)  The stars are at the same distance from Earth, were formed at approximately the same time, and were made from the same chemical mix.

Question 8

What is the dominant nuclear reaction during helium burning in the core of a star?

Accepted Answer

A)  ¹H + ⁴He combine to form C, 
B)  ⁴He fuses to form C. 
C)  ²He fuses to form C. 
D)  ³He fuses to form C. 
A)  ¹H + ⁴He combine to form C, 
B)  ⁴He fuses to form C. 
C)  ²He fuses to form C. 
D)  ³He fuses to form C.

Question 9

MOST of the energy emitted by a protostar comes from:

Accepted Answer

A)  radioactive elements. 
B)  gravitational potential energy being converted to heat as the protostar collapses. 
C)  infalling material colliding with the protostar's surface. 
D)  nuclear fusion. 
A)  radioactive elements. 
B)  gravitational potential energy being converted to heat as the protostar collapses. 
C)  infalling material colliding with the protostar's surface. 
D)  nuclear fusion.

Question 10

An astronomer plots the H-R diagram of a star cluster and finds that it contains hot B-type stars on the main sequence and cooler G- and K-type stars noticeably above the main sequence.This cluster is:

Accepted Answer

A)  of indeterminate age since the age of the cluster cannot be estimated from the information given. 
B)  impossible because cool stars cannot be above the main sequence when hot stars are on the main sequence. 
C)  old because the G and K stars are already evolving off (away from) the main sequence. 
D)  very young because the G and K stars are still evolving toward the main sequence. 
A)  of indeterminate age since the age of the cluster cannot be estimated from the information given. 
B)  impossible because cool stars cannot be above the main sequence when hot stars are on the main sequence. 
C)  old because the G and K stars are already evolving off (away from) the main sequence. 
D)  very young because the G and K stars are still evolving toward the main sequence.

Question 11

The H-R diagram for an open cluster gives special information because all stars in an open cluster are:

Accepted Answer

A)  the same age. 
B)  the same mass. 
C)  moving in the same direction. 
D)  the same spectral type. 
A)  the same age. 
B)  the same mass. 
C)  moving in the same direction. 
D)  the same spectral type.

Question 12

Stars are formed from interstellar matter.Why then are stars in open clusters metal-rich,while stars in globular clusters are metal-poor?

Accepted Answer

A)  Open clusters contain very hot stars that produce metals by nuclear reactions in their outer layers. 
B)  Globular clusters have "burned" their heavy elements over their longer lifetime. 
C)  Globular clusters are too young for their stars to have produced any significant amount of metals. 
D)  Open clusters are young and stars have formed from material that has been enriched in metals by supernova explosions of previous stars. 
A)  Open clusters contain very hot stars that produce metals by nuclear reactions in their outer layers. 
B)  Globular clusters have "burned" their heavy elements over their longer lifetime. 
C)  Globular clusters are too young for their stars to have produced any significant amount of metals. 
D)  Open clusters are young and stars have formed from material that has been enriched in metals by supernova explosions of previous stars.

Question 13

How is the length of a star's lifetime related to the mass of the star?

Accepted Answer

A)  Lower-mass stars run through their lives faster and have shorter lifetimes. 
B)  The lifetimes of stars are too long to measure, so it is not known how (or if) their lifetimes depend on mass. 
C)  A star's lifetime does not depend on its mass. 
D)  Higher-mass stars run through their lives faster and have shorter lifetimes. 
A)  Lower-mass stars run through their lives faster and have shorter lifetimes. 
B)  The lifetimes of stars are too long to measure, so it is not known how (or if) their lifetimes depend on mass. 
C)  A star's lifetime does not depend on its mass. 
D)  Higher-mass stars run through their lives faster and have shorter lifetimes.

Question 14

In terms of nuclear reactions,what is the next stage of a star's life after the end of hydrogen burning in the core?

Accepted Answer

A)  hydrogen burning in a thin shell around the core 
B)  helium burning in the core 
C)  carbon burning 
D)  death (it becomes either a supernova or a white dwarf) 
A)  hydrogen burning in a thin shell around the core 
B)  helium burning in the core 
C)  carbon burning 
D)  death (it becomes either a supernova or a white dwarf)

Question 15

If the universe is only 14 billion years old,which stars have never moved beyond the main sequence?

Accepted Answer

A)  stars with masses less than 0.08 solar mass 
B)  stars with masses less than 0.75 solar mass 
C)  stars with masses greater than 100 solar masses 
D)  stars with masses greater than 10 solar masses 
A)  stars with masses less than 0.08 solar mass 
B)  stars with masses less than 0.75 solar mass 
C)  stars with masses greater than 100 solar masses 
D)  stars with masses greater than 10 solar masses

Question 16

Why is it that the majority of stars in the sky are in the main-sequence phase of their lives?

Accepted Answer

A)  Most stars die at the end of the main-sequence phase. 
B)  The main-sequence phase is the longest-lasting phase in each star's life. 
C)  The main-sequence phase is the only phase that is common to all stars. 
D)  Most stars in the sky were created at about the same time, so these are all in the same phase of their lives. 
A)  Most stars die at the end of the main-sequence phase. 
B)  The main-sequence phase is the longest-lasting phase in each star's life. 
C)  The main-sequence phase is the only phase that is common to all stars. 
D)  Most stars in the sky were created at about the same time, so these are all in the same phase of their lives.

Question 17

What wavelengths have astronomers used to map and study the distribution of the giant molecular clouds in space?

Accepted Answer

A)  X-ray 
B)  visible 
C)  ultraviolet 
D)  radio 
A)  X-ray 
B)  visible 
C)  ultraviolet 
D)  radio

Question 18

A T Tauri star is at what stage of its stellar evolution?

Accepted Answer

A)  just before red giant phase, when variability begins 
B)  well established on the main sequence 
C)  the end of its life, decaying away and cooling 
D)  protostar, before the main-sequence phase 
A)  just before red giant phase, when variability begins 
B)  well established on the main sequence 
C)  the end of its life, decaying away and cooling 
D)  protostar, before the main-sequence phase

Question 19

Which factor,more than any other,modifies the evolutionary tracks of stars in binary combinations compared with their single-star counterparts?

Accepted Answer

A)  tidal distortion of the shapes of the stars 
B)  reduction of the quantum mechanical limitation on continued shrinking of one star by the gravitational field of the second star 
C)  mass exchange between the stars 
D)  radiation from one star heating the surface of the second star 
A)  tidal distortion of the shapes of the stars 
B)  reduction of the quantum mechanical limitation on continued shrinking of one star by the gravitational field of the second star 
C)  mass exchange between the stars 
D)  radiation from one star heating the surface of the second star

Question 20

If you look out in the night sky with your naked eye,what is the luminosity class of most of the stars you see? Are these actually the most numerous stars?

Accepted Answer

A)  You will see mostly main-sequence stars; yes, these are the most numerous of stars. 
B)  You will see mostly main-sequence stars, but most stars are actually giants. 
C)  You will see mostly giants, but most stars are actually main-sequence stars. 
D)  You will see mostly giants; yes, most stars are actually giants. 
A)  You will see mostly main-sequence stars; yes, these are the most numerous of stars. 
B)  You will see mostly main-sequence stars, but most stars are actually giants. 
C)  You will see mostly giants, but most stars are actually main-sequence stars. 
D)  You will see mostly giants; yes, most stars are actually giants.

What is the SECOND most abundant element in the universe (after hydrogen)?

What event occurs at the end of the protostar stage of a star's life?

A main-sequence star is defined as a star:

The transfer of mass from the surface of one star onto the surface of another is MOST often observed in _____ binaries.

What rates of mass loss from red giant stars are typical?

What fraction of the mass of a typical interstellar cloud is helium?

What are the main general features that make clusters of stars useful to astronomers?

What is the dominant nuclear reaction during helium burning in the core of a star?

MOST of the energy emitted by a protostar comes from:

An astronomer plots the H-R diagram of a star cluster and finds that it contains hot B-type stars on the main sequence and cooler G- and K-type stars noticeably above the main sequence.This cluster is:

The H-R diagram for an open cluster gives special information because all stars in an open cluster are:

Stars are formed from interstellar matter.Why then are stars in open clusters metal-rich,while stars in globular clusters are metal-poor?

How is the length of a star's lifetime related to the mass of the star?

In terms of nuclear reactions,what is the next stage of a star's life after the end of hydrogen burning in the core?

If the universe is only 14 billion years old,which stars have never moved beyond the main sequence?

Why is it that the majority of stars in the sky are in the main-sequence phase of their lives?

What wavelengths have astronomers used to map and study the distribution of the giant molecular clouds in space?

A T Tauri star is at what stage of its stellar evolution?

Which factor,more than any other,modifies the evolutionary tracks of stars in binary combinations compared with their single-star counterparts?

If you look out in the night sky with your naked eye,what is the luminosity class of most of the stars you see? Are these actually the most numerous stars?

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 the SECOND most abundant element in the universe (after hydrogen)?

What event occurs at the end of the protostar stage of a star's life?

A main-sequence star is defined as a star:

The transfer of mass from the surface of one star onto the surface of another is MOST often observed in _____ binaries.

What rates of mass loss from red giant stars are typical?

What fraction of the mass of a typical interstellar cloud is helium?

What are the main general features that make clusters of stars useful to astronomers?

What is the dominant nuclear reaction during helium burning in the core of a star?

MOST of the energy emitted by a protostar comes from:

An astronomer plots the H-R diagram of a star cluster and finds that it contains hot B-type stars on the main sequence and cooler G- and K-type stars noticeably above the main sequence.This cluster is:

The H-R diagram for an open cluster gives special information because all stars in an open cluster are:

Stars are formed from interstellar matter.Why then are stars in open clusters metal-rich,while stars in globular clusters are metal-poor?

How is the length of a star's lifetime related to the mass of the star?

In terms of nuclear reactions,what is the next stage of a star's life after the end of hydrogen burning in the core?

If the universe is only 14 billion years old,which stars have never moved beyond the main sequence?

Why is it that the majority of stars in the sky are in the main-sequence phase of their lives?

What wavelengths have astronomers used to map and study the distribution of the giant molecular clouds in space?

A T Tauri star is at what stage of its stellar evolution?

Which factor,more than any other,modifies the evolutionary tracks of stars in binary combinations compared with their single-star counterparts?

If you look out in the night sky with your naked eye,what is the luminosity class of most of the stars you see? Are these actually the most numerous stars?

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