Question 1

How does the method of energy generation inside main-sequence stars affect their internal structure?

Accepted Answer

The method of energy generation inside m

Question 2

Nuclear fusion in stars is controlled by the dependence of density on mass.

Accepted Answer

A) True 
 B)False

Question 3

Higher mass stars evolve more slowly to the main sequence than lower mass stars.

Accepted Answer

A) True 
 B)False

Question 4

Why is convection important in stars?

Accepted Answer

A) because it mixes the star's gases and increases the temperature of the star 
B) because it mixes the star's gases and transports energy outwards 
C) because it carries energy toward the core of the star 
D) because it carries the neutrinos to the surface of the star where they can escape 
A) because it mixes the star's gases and increases the temperature of the star 
B) because it mixes the star's gases and transports energy outwards 
C) because it carries energy toward the core of the star 
D) because it carries the neutrinos to the surface of the star where they can escape

Question 5

Molecular clouds are mapped using CO instead of hydrogen because CO is much more abundant than hydrogen in molecular clouds.

Accepted Answer

A) True 
 B)False

Question 6

Bok globules are small,dark fragments of the interstellar medium.

Accepted Answer

A) True 
 B)False

Question 7

How can molecular clouds be observed?

Accepted Answer

A) by using infrared telescopes to detect ionized gas in the clouds 
B) by using X-ray telescopes to observe the X-ray radiation from the molecules in the cloud 
C) by using radio telescopes to observe the emission from CO molecules in the clouds 
D) by using radio telescopes to observe the 21-cm radiation from hydrogen 
A) by using infrared telescopes to detect ionized gas in the clouds 
B) by using X-ray telescopes to observe the X-ray radiation from the molecules in the cloud 
C) by using radio telescopes to observe the emission from CO molecules in the clouds 
D) by using radio telescopes to observe the 21-cm radiation from hydrogen

Question 8

What is the lifetime of a 10 solar mass star on the main sequence?

Accepted Answer

A) 3.2×10⁷ years 
B) 1×10⁹ years 
C) 1×10¹¹ years 
D) 3.2×10¹² years 
A) 3.2×10⁷ years 
B) 1×10⁹ years 
C) 1×10¹¹ years 
D) 3.2×10¹² years

Question 9

The Sun has an expected main-sequence lifetime of about 10¹⁰ years.What is the lifetime on the main sequence of a 2 solar mass star?

Accepted Answer

A) 1.8×10⁶ years 
B) 1.8×10⁹ years 
C) 1.8×10¹⁰ yearsα 
D) 1.8×10¹¹ years 
A) 1.8×10⁶ years 
B) 1.8×10⁹ years 
C) 1.8×10¹⁰ yearsα 
D) 1.8×10¹¹ years

Question 10

The thermal motions of the atoms in a gas cloud can make it collapse to form a protostar.

Accepted Answer

A) True 
 B)False

Question 11

A(n)____________________ is a subatomic particle produced in nuclear fusion that can travel through the Sun and escape to space without interacting with any particles in the Sun.

Accepted Answer

The answer of A(n)____________________ is a subatomic particle produced in...

Question 12

The pressure of an interstellar gas cloud depends on the cloud's ____________________ and ____________________.

Accepted Answer

temperatur

Question 13

Consider two stars of the same mass: star 1 has just moved on to the main sequence,and star 2 is about to leave it.How are these two stars different?

Accepted Answer

A) Star 2 has more helium in its core and a hotter surface. 
B) Star 2 has more helium in its core and a cooler surface. 
C) Star 1 is more luminous and has a hotter surface. 
D) Star 1 is more luminous and has a cooler surface. 
A) Star 2 has more helium in its core and a hotter surface. 
B) Star 2 has more helium in its core and a cooler surface. 
C) Star 1 is more luminous and has a hotter surface. 
D) Star 1 is more luminous and has a cooler surface.

Question 14

Stars of one solar mass produce their energy by the set of nuclear reactions called the CNO cycle.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following are small dark nebulae about 1 light year in diameter,with masses from 10 to 1,000 solar masses?

Accepted Answer

A) HII regions 
B) emission nebulae 
C) Bok globules 
D) reflection nebulae 
A) HII regions 
B) emission nebulae 
C) Bok globules 
D) reflection nebulae

Question 16

As a human with a temperature of about 310 K,you radiate most strongly at a wavelength of about 10 micrometres.If the dust around a protostar radiates most strongly at 30 micrometres,what is the approximate temperature of that dust?

Accepted Answer

A) 100,000 K 
B) 10,000 K 
C) 1000 K 
D) 100 K 
A) 100,000 K 
B) 10,000 K 
C) 1000 K 
D) 100 K

Question 17

When energy is carried by the bulk motion of matter,that is called ____________________.

Accepted Answer

The answer of When energy is carried by the bulk...

Question 18

Which of the following is most similar in size to a brown dwarf?

Accepted Answer

A) the planet Jupiter 
B) a red dwarf 
C) a white dwarf 
D) a Bok globule 
A) the planet Jupiter 
B) a red dwarf 
C) a white dwarf 
D) a Bok globule

Question 19

Which of the following relationships is the key to nuclear reactions in a star's core remaining under control?

Accepted Answer

A) Luminosity depends on mass. 
B) Pressure depends on temperature. 
C) Density depends on mass. 
D) Weight depends on temperature. 
A) Luminosity depends on mass. 
B) Pressure depends on temperature. 
C) Density depends on mass. 
D) Weight depends on temperature.

Question 20

The solar neutrino experiments detected about twice as many neutrinos as theory predicted should be detected.

Accepted Answer

A) True 
 B)False

How does the method of energy generation inside main-sequence stars affect their internal structure?

Nuclear fusion in stars is controlled by the dependence of density on mass.

Higher mass stars evolve more slowly to the main sequence than lower mass stars.

Why is convection important in stars?

Molecular clouds are mapped using CO instead of hydrogen because CO is much more abundant than hydrogen in molecular clouds.

Bok globules are small,dark fragments of the interstellar medium.

How can molecular clouds be observed?

What is the lifetime of a 10 solar mass star on the main sequence?

The Sun has an expected main-sequence lifetime of about 10¹⁰ years.What is the lifetime on the main sequence of a 2 solar mass star?

The thermal motions of the atoms in a gas cloud can make it collapse to form a protostar.

A(n)____________________ is a subatomic particle produced in nuclear fusion that can travel through the Sun and escape to space without interacting with any particles in the Sun.

The pressure of an interstellar gas cloud depends on the cloud's and .

Consider two stars of the same mass: star 1 has just moved on to the main sequence,and star 2 is about to leave it.How are these two stars different?

Stars of one solar mass produce their energy by the set of nuclear reactions called the CNO cycle.

Which of the following are small dark nebulae about 1 light year in diameter,with masses from 10 to 1,000 solar masses?

As a human with a temperature of about 310 K,you radiate most strongly at a wavelength of about 10 micrometres.If the dust around a protostar radiates most strongly at 30 micrometres,what is the approximate temperature of that dust?

When energy is carried by the bulk motion of matter,that is called ____________________.

Which of the following is most similar in size to a brown dwarf?

Which of the following relationships is the key to nuclear reactions in a star's core remaining under control?

The solar neutrino experiments detected about twice as many neutrinos as theory predicted should be detected.

The Scale of the Cosmos

User's Guide to the Sky

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments

Sun Light and Sun Atoms

The Family of Stars

The Deaths of Stars

The Milky Way Galaxy

Galaxies

Cosmology in the 21st Century

The Origin of the Solar System

Comparative Planetology of the Terrestrial Planets

Comparative Planetology of the Jovian Planets

Life on Other Worlds

Filters

Exam 7: The Structure and Formation of Stars

How does the method of energy generation inside main-sequence stars affect their internal structure?

Nuclear fusion in stars is controlled by the dependence of density on mass.

Higher mass stars evolve more slowly to the main sequence than lower mass stars.

Why is convection important in stars?

Molecular clouds are mapped using CO instead of hydrogen because CO is much more abundant than hydrogen in molecular clouds.

Bok globules are small,dark fragments of the interstellar medium.

How can molecular clouds be observed?

What is the lifetime of a 10 solar mass star on the main sequence?

The Sun has an expected main-sequence lifetime of about 10¹⁰ years.What is the lifetime on the main sequence of a 2 solar mass star?

The thermal motions of the atoms in a gas cloud can make it collapse to form a protostar.

A(n)____________________ is a subatomic particle produced in nuclear fusion that can travel through the Sun and escape to space without interacting with any particles in the Sun.

The pressure of an interstellar gas cloud depends on the cloud's ____________________ and ____________________.

Consider two stars of the same mass: star 1 has just moved on to the main sequence,and star 2 is about to leave it.How are these two stars different?

Stars of one solar mass produce their energy by the set of nuclear reactions called the CNO cycle.

Which of the following are small dark nebulae about 1 light year in diameter,with masses from 10 to 1,000 solar masses?

As a human with a temperature of about 310 K,you radiate most strongly at a wavelength of about 10 micrometres.If the dust around a protostar radiates most strongly at 30 micrometres,what is the approximate temperature of that dust?

When energy is carried by the bulk motion of matter,that is called ____________________.

Which of the following is most similar in size to a brown dwarf?

Which of the following relationships is the key to nuclear reactions in a star's core remaining under control?

The solar neutrino experiments detected about twice as many neutrinos as theory predicted should be detected.

The Scale of the Cosmos

User's Guide to the Sky

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments

Sun Light and Sun Atoms

The Family of Stars

The Deaths of Stars

The Milky Way Galaxy

Galaxies

Cosmology in the 21st Century

The Origin of the Solar System

Comparative Planetology of the Terrestrial Planets

Comparative Planetology of the Jovian Planets

Life on Other Worlds

Filters

The pressure of an interstellar gas cloud depends on the cloud's and .