Question 1

What are the stars in the upper part of the instability strip called?

Accepted Answer

A)  protostars 
B)  T Tauri stars 
C)  RR Lyrae variables 
D)  Cepheid variables 
A)  protostars 
B)  T Tauri stars 
C)  RR Lyrae variables 
D)  Cepheid variables

Question 2

Two close binary stars exchange mass.Each of the following statements describes a possible outcome of such a mass exchange EXCEPT ONE.Which is the exception?

Accepted Answer

A)  The star that was originally smaller can become the larger of the two. 
B)  An accretion disk can be formed around one of the stars which can almost block it from view. 
C)  One of the stars can begin to spin so rapidly that its shape will be distorted. 
D)  The two stars can merge to form a single star and then fly apart to form two wholly new stars. 
A)  The star that was originally smaller can become the larger of the two. 
B)  An accretion disk can be formed around one of the stars which can almost block it from view. 
C)  One of the stars can begin to spin so rapidly that its shape will be distorted. 
D)  The two stars can merge to form a single star and then fly apart to form two wholly new stars.

Question 3

A brown dwarf is a:

Accepted Answer

A)  high-mass star surrounded by an extensive and cool atmosphere of dust and gas. 
B)  star of mass less than about 0.08 solar mass whose core temperature is too low to initiate hydrogen fusion. 
C)  type of asteroid, so named because of its color, which indicates oxidized iron, or rust. 
D)  star in the late phases of evolution following the red giant phase whose temperature is very low-hence the brown color. 
A)  high-mass star surrounded by an extensive and cool atmosphere of dust and gas. 
B)  star of mass less than about 0.08 solar mass whose core temperature is too low to initiate hydrogen fusion. 
C)  type of asteroid, so named because of its color, which indicates oxidized iron, or rust. 
D)  star in the late phases of evolution following the red giant phase whose temperature is very low-hence the brown color.

Question 4

If a protostar were able to contract (get smaller)without any change in its surface temperature,what would happen to its luminosity?

Accepted Answer

A)  It is not possible to predict the change in the protostar's luminosity since other factors are involved. 
B)  The star's luminosity would increase due to the compression of the gas. 
C)  The star's luminosity would decrease due to the reduced surface area of the protostar. 
D)  The star's luminosity would remain the same since the temperature does not change. 
A)  It is not possible to predict the change in the protostar's luminosity since other factors are involved. 
B)  The star's luminosity would increase due to the compression of the gas. 
C)  The star's luminosity would decrease due to the reduced surface area of the protostar. 
D)  The star's luminosity would remain the same since the temperature does not change.

Question 5

Which method has NOT yet been used to study the material of the interstellar medium?

Accepted Answer

A)  scattering of starlight 
B)  collection of dust and gas by spacecraft 
C)  emission of electromagnetic radiation by atoms and molecules 
D)  absorption of light from more distant stars 
A)  scattering of starlight 
B)  collection of dust and gas by spacecraft 
C)  emission of electromagnetic radiation by atoms and molecules 
D)  absorption of light from more distant stars

Question 6

When a star's evolutionary track in the Hertzsprung-Russell diagram carries it into the instability strip,what happens to the star?

Accepted Answer

A)  The star pulsates randomly in brightness. 
B)  The star collapses and forms a black hole. 
C)  The star explodes. 
D)  The star pulsates regularly in brightness. 
A)  The star pulsates randomly in brightness. 
B)  The star collapses and forms a black hole. 
C)  The star explodes. 
D)  The star pulsates regularly in brightness.

Question 7

Some protostars,when they evolve onto the main sequence,are fully convective and use convection to transport material all the way from the core to the surface.Which stars show this characteristic?

Accepted Answer

A)  only the smallest, of less than about 0.4 solar mass 
B)  intermediate stars, of about 0.4 solar mass up to about 4 solar masses 
C)  the largest, of more than about 4 solar masses 
D)  all protostars 
A)  only the smallest, of less than about 0.4 solar mass 
B)  intermediate stars, of about 0.4 solar mass up to about 4 solar masses 
C)  the largest, of more than about 4 solar masses 
D)  all protostars

Question 8

What are the TWO MOST abundant elements in the universe?

Accepted Answer

A)  hydrogen and carbon 
B)  hydrogen and oxygen 
C)  hydrogen and helium 
D)  nitrogen and oxygen 
A)  hydrogen and carbon 
B)  hydrogen and oxygen 
C)  hydrogen and helium 
D)  nitrogen and oxygen

Question 9

A low-mass red dwarf (0.08 M < M < 0.4 M)will eventually NOT become a:

Accepted Answer

A)  red giant. 
B)  brown dwarf. 
C)  white dwarf. 
D)  red giant, a brown dwarf, or a white dwarf. 
A)  red giant. 
B)  brown dwarf. 
C)  white dwarf. 
D)  red giant, a brown dwarf, or a white dwarf.

Question 10

In some binary star systems,such as Algol,the less massive star is an old red giant and the more massive star is on the main sequence,evidence that:

Accepted Answer

A)  the more massive star captured the other one into orbit some time after the two stars had formed. 
B)  the more massive star formed later, from a disk of gas surrounding the less massive star. 
C)  mass transfer from one of the stars to the other has occurred. 
D)  stars evolve differently in binary star systems, with less massive stars evolving faster than more massive stars. 
A)  the more massive star captured the other one into orbit some time after the two stars had formed. 
B)  the more massive star formed later, from a disk of gas surrounding the less massive star. 
C)  mass transfer from one of the stars to the other has occurred. 
D)  stars evolve differently in binary star systems, with less massive stars evolving faster than more massive stars.

Question 11

For an astronomer,what is the significance of the turnoff point in the Hertzsprung-Russell diagram of a star cluster?

Accepted Answer

A)  The turnoff point tells the astronomer the age of the star cluster. 
B)  The turnoff point tells the astronomer which stars might be about to explode as supernovas. 
C)  The turnoff point tells the astronomer which stars pulsate in brightness (variable stars). 
D)  The turnoff point tells the astronomer the metal content of the star cluster. 
A)  The turnoff point tells the astronomer the age of the star cluster. 
B)  The turnoff point tells the astronomer which stars might be about to explode as supernovas. 
C)  The turnoff point tells the astronomer which stars pulsate in brightness (variable stars). 
D)  The turnoff point tells the astronomer the metal content of the star cluster.

Question 12

Which part of the Hertzsprung-Russell diagram is occupied by protostars?

Accepted Answer

A)  to the left of the main sequence 
B)  the band running from upper right to lower left 
C)  the band running from upper left to lower right 
D)  to the right of the main sequence 
A)  to the left of the main sequence 
B)  the band running from upper right to lower left 
C)  the band running from upper left to lower right 
D)  to the right of the main sequence

Question 13

The group of stars that is formed when a giant molecular cloud collapses is called a(n):

Accepted Answer

A)  open cluster. 
B)  galaxy. 
C)  constellation. 
D)  gravitational lens. 
A)  open cluster. 
B)  galaxy. 
C)  constellation. 
D)  gravitational lens.

Question 14

How does the temperature of an interstellar cloud affect its ability to form stars?

Accepted Answer

A)  Higher temperatures help star formation. 
B)  Star formation is independent of the temperature of the cloud. 
C)  Star formation is too complicated to be able to say how one quantity, such as temperature, affects it. 
D)  Higher temperatures inhibit star formation. 
A)  Higher temperatures help star formation. 
B)  Star formation is independent of the temperature of the cloud. 
C)  Star formation is too complicated to be able to say how one quantity, such as temperature, affects it. 
D)  Higher temperatures inhibit star formation.

Question 15

Which wavelength region is MOST useful for investigating the dense cores inside giant molecular clouds?

Accepted Answer

A)  infrared 
B)  X-ray 
C)  ultraviolet 
D)  optical 
A)  infrared 
B)  X-ray 
C)  ultraviolet 
D)  optical

Question 16

The stars that last longest are the stars:

Accepted Answer

A)  with the largest luminosity and highest temperature since they take the longest to cool down to invisibility. 
B)  with the largest mass, that is, the largest amount of fuel. 
C)  with the smallest mass. 
D)  of intermediate mass; small-mass stars have little fuel and burn out quickly, while very massive stars burn their fuel very rapidly. 
A)  with the largest luminosity and highest temperature since they take the longest to cool down to invisibility. 
B)  with the largest mass, that is, the largest amount of fuel. 
C)  with the smallest mass. 
D)  of intermediate mass; small-mass stars have little fuel and burn out quickly, while very massive stars burn their fuel very rapidly.

Question 17

Which property is a known characteristic of a T Tauri star?

Accepted Answer

A)  ejection of mass into space 
B)  great age, near the end of its life as a star 
C)  high mass, greater than about 3 solar masses 
D)  nuclear reactions in the core 
A)  ejection of mass into space 
B)  great age, near the end of its life as a star 
C)  high mass, greater than about 3 solar masses 
D)  nuclear reactions in the core

Question 18

If you make a list of the 100 brightest stars in the sky,you will find that most of them are:

Accepted Answer

A)  white dwarfs. 
B)  main-sequence stars. 
C)  giants and supergiants. 
D)  brown dwarfs. 
A)  white dwarfs. 
B)  main-sequence stars. 
C)  giants and supergiants. 
D)  brown dwarfs.

Question 19

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

Accepted Answer

A)  2% 
B)  almost 50% 
C)  74% 
D)  98% 
A)  2% 
B)  almost 50% 
C)  74% 
D)  98%

Question 20

How many stars are there in a large globular cluster?

Accepted Answer

A)  about 1 million 
B)  about 1000 
C)  up to 100 billion 
D)  only a few dozen 
A)  about 1 million 
B)  about 1000 
C)  up to 100 billion 
D)  only a few dozen

What are the stars in the upper part of the instability strip called?

Two close binary stars exchange mass.Each of the following statements describes a possible outcome of such a mass exchange EXCEPT ONE.Which is the exception?

A brown dwarf is a:

If a protostar were able to contract (get smaller)without any change in its surface temperature,what would happen to its luminosity?

Which method has NOT yet been used to study the material of the interstellar medium?

When a star's evolutionary track in the Hertzsprung-Russell diagram carries it into the instability strip,what happens to the star?

Some protostars,when they evolve onto the main sequence,are fully convective and use convection to transport material all the way from the core to the surface.Which stars show this characteristic?

What are the TWO MOST abundant elements in the universe?

A low-mass red dwarf (0.08 M < M < 0.4 M)will eventually NOT become a:

In some binary star systems,such as Algol,the less massive star is an old red giant and the more massive star is on the main sequence,evidence that:

For an astronomer,what is the significance of the turnoff point in the Hertzsprung-Russell diagram of a star cluster?

Which part of the Hertzsprung-Russell diagram is occupied by protostars?

The group of stars that is formed when a giant molecular cloud collapses is called a(n):

How does the temperature of an interstellar cloud affect its ability to form stars?

Which wavelength region is MOST useful for investigating the dense cores inside giant molecular clouds?

The stars that last longest are the stars:

Which property is a known characteristic of a T Tauri star?

If you make a list of the 100 brightest stars in the sky,you will find that most of them are:

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

How many stars are there in a large globular cluster?

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

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

What are the stars in the upper part of the instability strip called?

Two close binary stars exchange mass.Each of the following statements describes a possible outcome of such a mass exchange EXCEPT ONE.Which is the exception?

A brown dwarf is a:

If a protostar were able to contract (get smaller)without any change in its surface temperature,what would happen to its luminosity?

Which method has NOT yet been used to study the material of the interstellar medium?

When a star's evolutionary track in the Hertzsprung-Russell diagram carries it into the instability strip,what happens to the star?

Some protostars,when they evolve onto the main sequence,are fully convective and use convection to transport material all the way from the core to the surface.Which stars show this characteristic?

What are the TWO MOST abundant elements in the universe?

A low-mass red dwarf (0.08 M < M < 0.4 M)will eventually NOT become a:

In some binary star systems,such as Algol,the less massive star is an old red giant and the more massive star is on the main sequence,evidence that:

For an astronomer,what is the significance of the turnoff point in the Hertzsprung-Russell diagram of a star cluster?

Which part of the Hertzsprung-Russell diagram is occupied by protostars?

The group of stars that is formed when a giant molecular cloud collapses is called a(n):

How does the temperature of an interstellar cloud affect its ability to form stars?

Which wavelength region is MOST useful for investigating the dense cores inside giant molecular clouds?

The stars that last longest are the stars:

Which property is a known characteristic of a T Tauri star?

If you make a list of the 100 brightest stars in the sky,you will find that most of them are:

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

How many stars are there in a large globular cluster?

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