Question 1

What type of star is our Sun?

Accepted Answer

A) a low- mass star 
B) a high- mass star 
C) an intermediate- mass star 
A) a low- mass star 
B) a high- mass star 
C) an intermediate- mass star

Question 2

What is the fate of an isolated brown dwarf?

Accepted Answer

A) It will become a neutron star. 
B) It will slowly evaporate to nothing. 
C) It will become a white dwarf. 
D) It will remain a brown dwarf forever. 
E) It will become a black hole. 
A) It will become a neutron star. 
B) It will slowly evaporate to nothing. 
C) It will become a white dwarf. 
D) It will remain a brown dwarf forever. 
E) It will become a black hole.

Question 3

Which of the following phenomena is not commonly associated with the star formation process?

Accepted Answer

A) intense ultraviolet radiation coming from a protostar 
B) strong winds of particles blowing out into space from a protostar 
C) powerful "jets" shooting out along the rotation axis of a protostar 
D) the formation of a spinning disk of material around a protostar 
A) intense ultraviolet radiation coming from a protostar 
B) strong winds of particles blowing out into space from a protostar 
C) powerful "jets" shooting out along the rotation axis of a protostar 
D) the formation of a spinning disk of material around a protostar

Question 4

Which of the following sequences correctly describes the stages of life for a low- mass star?

Accepted Answer

A) white dwarf, main- sequence, red giant, protostar 
B) protostar, red giant, main- sequence, white dwarf 
C) red giant, protostar, main- sequence, white dwarf 
D) protostar, main- sequence, white dwarf, red giant 
E) protostar, main- sequence, red giant, white dwarf 
A) white dwarf, main- sequence, red giant, protostar 
B) protostar, red giant, main- sequence, white dwarf 
C) red giant, protostar, main- sequence, white dwarf 
D) protostar, main- sequence, white dwarf, red giant 
E) protostar, main- sequence, red giant, white dwarf

Question 5

At the end of its life, the remaining core of this star will be left behind as

Accepted Answer

A) a black hole. 
B) a supernova. 
C) a white dwarf made primarily of silicon and iron. 
D) a white dwarf made primarily of carbon and oxygen. 
E) a neutron star. 
A) a black hole. 
B) a supernova. 
C) a white dwarf made primarily of silicon and iron. 
D) a white dwarf made primarily of carbon and oxygen. 
E) a neutron star.

Question 6

Briefly summarize the stages of life for a low- mass star.

Accepted Answer

The protostar assembles from the molecul

Question 7

Which of the following statements about the stages of nuclear burning in a massive star is not true?

Accepted Answer

A) Each successive stage lasts for approximately as long as the first, hydrogen fusion stage. 
B) Each successive stage of fusion requires higher temperatures than the previous stages. 
C) As each stage ends, the core shrinks further. 
D) Each successive stage creates an element with a higher atomic weight. 
A) Each successive stage lasts for approximately as long as the first, hydrogen fusion stage. 
B) Each successive stage of fusion requires higher temperatures than the previous stages. 
C) As each stage ends, the core shrinks further. 
D) Each successive stage creates an element with a higher atomic weight.

Question 8

Compared to the star it evolved from, a white dwarf is

Accepted Answer

A) cooler and brighter. 
B) hotter and dimmer. 
C) hotter and brighter. 
D) the same temperature and brightness. 
E) cooler and dimmer. 
A) cooler and brighter. 
B) hotter and dimmer. 
C) hotter and brighter. 
D) the same temperature and brightness. 
E) cooler and dimmer.

Question 9

Why don't low- mass stars have the CNO cycle occurring in their cores?

Accepted Answer

A) Their core temperatures are too low. 
B) The CNO cycle makes elements heavier than carbon, nitrogen, and oxygen. 
C) They don't have enough carbon, nitrogen, and oxygen. 
A) Their core temperatures are too low. 
B) The CNO cycle makes elements heavier than carbon, nitrogen, and oxygen. 
C) They don't have enough carbon, nitrogen, and oxygen.

Question 10

No stars are expected with masses greater than 150 times our Sun because

Accepted Answer

A) they would fragment into binary stars because of their rapid rotation. 
B) they would generate so much power that they would blow themselves apart. 
C) they would be too massive for hydrogen fusion to occur in their cores. 
D) they would shine exclusively at X- ray wavelengths and would be difficult to detect. 
E) molecular clouds do not have enough material to form such massive stars. 
A) they would fragment into binary stars because of their rapid rotation. 
B) they would generate so much power that they would blow themselves apart. 
C) they would be too massive for hydrogen fusion to occur in their cores. 
D) they would shine exclusively at X- ray wavelengths and would be difficult to detect. 
E) molecular clouds do not have enough material to form such massive stars.

Question 11

The overall helium fusion reaction is _ .

Accepted Answer

A) three helium nuclei fuse to form one carbon nucleus 
B) two helium nuclei fuse to form one beryllium nucleus 
C) four helium nuclei fuse to form one oxygen nucleus 
D) two hydrogen nuclei fuse to form one helium nucleus 
A) three helium nuclei fuse to form one carbon nucleus 
B) two helium nuclei fuse to form one beryllium nucleus 
C) four helium nuclei fuse to form one oxygen nucleus 
D) two hydrogen nuclei fuse to form one helium nucleus

Question 12

Which of the following lists the stages of life for a low- mass star in the correct order?

Accepted Answer

A) protostar, main- sequence star, red giant, planetary nebula, white dwarf 
B) protostar, main- sequence star, planetary nebula, red giant 
C) protostar, main- sequence star, red giant, supernova, neutron star 
D) main- sequence star, white dwarf, red giant, planetary nebula, protostar 
A) protostar, main- sequence star, red giant, planetary nebula, white dwarf 
B) protostar, main- sequence star, planetary nebula, red giant 
C) protostar, main- sequence star, red giant, supernova, neutron star 
D) main- sequence star, white dwarf, red giant, planetary nebula, protostar

Question 13

You discover a binary star system in which one star is a 15 MSun main- sequence star and the other is a 10 MSun giant. How do we think that a star system such as this might have come to exist?

Accepted Answer

A) The giant must once have been the more massive star, but is now less massive because it transferred some of its mass to its companion. 
B) The two stars are simply evolving normally and independently, and one has become a giant before the other. 
C) The two stars probably were once separate, but became a binary when a close encounter allowed their mutual gravity to pull them together. 
D) Although both stars probably formed from the same clump of gas, the more massive one must have had its birth slowed so that it became a main sequence stars millions of years later than its less massive companion. 
A) The giant must once have been the more massive star, but is now less massive because it transferred some of its mass to its companion. 
B) The two stars are simply evolving normally and independently, and one has become a giant before the other. 
C) The two stars probably were once separate, but became a binary when a close encounter allowed their mutual gravity to pull them together. 
D) Although both stars probably formed from the same clump of gas, the more massive one must have had its birth slowed so that it became a main sequence stars millions of years later than its less massive companion.

Question 14

The figure above shows the abundance of elements in the galaxy relative to hydrogen. What is the least abundant of the elements with an atomic number less than iron's?

Accepted Answer

A) beryllium 
B) hydrogen 
C) nitrogen 
D) lithium 
A) beryllium 
B) hydrogen 
C) nitrogen 
D) lithium

Question 15

Where does gold (the element)come from?

Accepted Answer

A) It is produced by mass transfer in close binaries. 
B) It is produced during the late stages of fusion in low- mass stars. 
C) It was produced during the Big Bang. 
D) It is produced during the supernova explosions of high- mass stars. 
A) It is produced by mass transfer in close binaries. 
B) It is produced during the late stages of fusion in low- mass stars. 
C) It was produced during the Big Bang. 
D) It is produced during the supernova explosions of high- mass stars.

Question 16

Compared to the star it evolved from, a red giant is

Accepted Answer

A) hotter and brighter. 
B) hotter and dimmer. 
C) cooler and brighter. 
D) the same temperature and brightness. 
E) cooler and dimmer. 
A) hotter and brighter. 
B) hotter and dimmer. 
C) cooler and brighter. 
D) the same temperature and brightness. 
E) cooler and dimmer.

Question 17

The vast majority of stars in a newly formed star cluster are .

Accepted Answer

A) very high- mass, type O and B stars 
B) red giants 
C) about the same mass as our Sun 
D) less massive than the Sun 
A) very high- mass, type O and B stars 
B) red giants 
C) about the same mass as our Sun 
D) less massive than the Sun

Question 18

Stellar Evolution as a Scientific Theory: Based on the chapter material, list what you feel are the basic founding assumptions of the theory of stellar evolution. For example, you might list that stars are assumed to be balls of mostly hydrogen gas held together by their own gravity. After this, make another list of as many of the successful predictions of this theory as you can. Based on the comparison of these two lists, how successful a scientific theory would you rate the theory of stellar evolution?

Accepted Answer

Basic founding assumptions of the theory

Question 19

Algol consists of a 3.7 MSun main- sequence star and a 0.8 MSun subgiant. Why does this seem surprising, at least at first?

Accepted Answer

A) The two stars should be the same age, so we'd expect the subgiant to be more massive than the main- sequence star. 
B) A star with a mass of 3.7 MSun is too big to be a main sequence star. 
C) It doesn't make sense to find a subgiant in a binary star system. 
D) The two stars in a binary system should both be at the same stage of life; that is, they should either both be main sequence stars or both be subgiants. 
A) The two stars should be the same age, so we'd expect the subgiant to be more massive than the main- sequence star. 
B) A star with a mass of 3.7 MSun is too big to be a main sequence star. 
C) It doesn't make sense to find a subgiant in a binary star system. 
D) The two stars in a binary system should both be at the same stage of life; that is, they should either both be main sequence stars or both be subgiants.

Question 20

What happens when a star like the sun exhausts its core hydrogen supply?

Accepted Answer

A) It expands, becoming bigger but dimmer. 
B) Its core contracts, but its outer layers expand and the star becomes bigger and brighter. 
C) It contracts, becoming hotter and brighter. 
D) It contracts, becoming smaller and dimmer. 
E) Its core contracts, but its outer layers expand and the star becomes bigger but cooler and therefore remains at the same brightness. 
A) It expands, becoming bigger but dimmer. 
B) Its core contracts, but its outer layers expand and the star becomes bigger and brighter. 
C) It contracts, becoming hotter and brighter. 
D) It contracts, becoming smaller and dimmer. 
E) Its core contracts, but its outer layers expand and the star becomes bigger but cooler and therefore remains at the same brightness.

What type of star is our Sun?

What is the fate of an isolated brown dwarf?

Which of the following phenomena is not commonly associated with the star formation process?

Which of the following sequences correctly describes the stages of life for a low- mass star?

At the end of its life, the remaining core of this star will be left behind as

Briefly summarize the stages of life for a low- mass star.

Which of the following statements about the stages of nuclear burning in a massive star is not true?

Compared to the star it evolved from, a white dwarf is

Why don't low- mass stars have the CNO cycle occurring in their cores?

No stars are expected with masses greater than 150 times our Sun because

The overall helium fusion reaction is _ .

Which of the following lists the stages of life for a low- mass star in the correct order?

You discover a binary star system in which one star is a 15 MSun main- sequence star and the other is a 10 MSun giant. How do we think that a star system such as this might have come to exist?

The figure above shows the abundance of elements in the galaxy relative to hydrogen. What is the least abundant of the elements with an atomic number less than iron's?

Where does gold (the element)come from?

Compared to the star it evolved from, a red giant is

The vast majority of stars in a newly formed star cluster are .

Algol consists of a 3.7 MSun main- sequence star and a 0.8 MSun subgiant. Why does this seem surprising, at least at first?

What happens when a star like the sun exhausts its core hydrogen supply?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters

Exam 13: Star Stuff

What type of star is our Sun?

What is the fate of an isolated brown dwarf?

Which of the following phenomena is not commonly associated with the star formation process?

Which of the following sequences correctly describes the stages of life for a low- mass star?

At the end of its life, the remaining core of this star will be left behind as

Briefly summarize the stages of life for a low- mass star.

Which of the following statements about the stages of nuclear burning in a massive star is not true?

Compared to the star it evolved from, a white dwarf is

Why don't low- mass stars have the CNO cycle occurring in their cores?

No stars are expected with masses greater than 150 times our Sun because

The overall helium fusion reaction is _ .

Which of the following lists the stages of life for a low- mass star in the correct order?

You discover a binary star system in which one star is a 15 MSun main- sequence star and the other is a 10 MSun giant. How do we think that a star system such as this might have come to exist?

The figure above shows the abundance of elements in the galaxy relative to hydrogen. What is the least abundant of the elements with an atomic number less than iron's?

Where does gold (the element)come from?

Compared to the star it evolved from, a red giant is

The vast majority of stars in a newly formed star cluster are .

Algol consists of a 3.7 MSun main- sequence star and a 0.8 MSun subgiant. Why does this seem surprising, at least at first?

What happens when a star like the sun exhausts its core hydrogen supply?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters