Question 1

The sun makes most of its energy by the CNO cycle.

Accepted Answer

A) True 
 B)False

Question 2

The pressure of a gas depends on the temperature and density of the gas.

Accepted Answer

A) True 
 B)False

Question 3

____ are star-like objects that contain less than 0.08 solar masses an will never raise their core temperatures high enough that the proton-proton chain can begin. Other minor fusion reactions do occur in these objects. They fall in a gap between the low-mass M dwarf stars and the massive planets in which nuclear fusion never occurs.

Accepted Answer

A)  Brown dwarfs 
B)  Herbig-Haro objects 
C)  Bok globules 
D)  T-Tauri star 
E)  Main sequence stars 
A)  Brown dwarfs 
B)  Herbig-Haro objects 
C)  Bok globules 
D)  T-Tauri star 
E)  Main sequence stars

Question 4

T Tauri stars are believed to be young, high mass main sequence stars.

Accepted Answer

A) True 
 B)False

Question 5

The diagram below is an HR diagram. The line indicates the location of the main sequence. Which of the five labeled locations on the HR diagram indicates a luminosity and temperature similar to that of a T Tauri star?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 6

If the dust around a protostar radiates most strongly at 30 microns or 30,000 nm, what is the approximate temperature of that dust? Hint: T in K =3,000,000/wavelength in nm.

Accepted Answer

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

Question 7

Which of the following is suggested as the best explanation of the missing solar neutrinos?

Accepted Answer

A)  The sun is fusing helium but not hydrogen. 
B)  Nuclear reactions do not produce neutrinos as fast as theory predicts. 
C)  The sun may contain matter we haven t yet identified. 
D)  Neutrinos may oscillate between three different flavors. 
E)  None of the above 
A)  The sun is fusing helium but not hydrogen. 
B)  Nuclear reactions do not produce neutrinos as fast as theory predicts. 
C)  The sun may contain matter we haven t yet identified. 
D)  Neutrinos may oscillate between three different flavors. 
E)  None of the above

Question 8

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

Accepted Answer

A)  3.2 10 7 years 
B)  320 years 
C)  3.2 10 12 years 
D)  1 10 9 years 
E)  1 10 11 years 
A)  3.2 10 7 years 
B)  320 years 
C)  3.2 10 12 years 
D)  1 10 9 years 
E)  1 10 11 years

Question 9

Hydrostatic equilibrium refers to the balance between weight and pressure.

Accepted Answer

A) True 
 B)False

Question 10

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...

Question 11

The ____ is the nuclear fusion of three helium nuclei to form a carbon nucleus.

Accepted Answer

A)  proton-proton chain 
B)  Carbon-Nitrogen-Oxygen cycle (CNO cycle) 
C)  triple-alpha process 
D)  Coulomb barrier 
E)  infrared cirrus 
A)  proton-proton chain 
B)  Carbon-Nitrogen-Oxygen cycle (CNO cycle) 
C)  triple-alpha process 
D)  Coulomb barrier 
E)  infrared cirrus

Question 12

Why is there a lower end to the main sequence? Why is there an upper end to the main sequence?

Accepted Answer

The main sequence is a continuous and di

Question 13

Why do nuclear reactions in a star occur only near its center?

Accepted Answer

The answer of Why do nuclear reactions in a star...

Question 14

HII regions are found near stars cooler than 25,000 K because large amounts of ultraviolet photons would totally destroy the hydrogen atoms in the gas.

Accepted Answer

A) True 
 B)False

Question 15

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

Accepted Answer

A) True 
 B)False

Question 16

The proton-proton chain

Accepted Answer

A)  combines two hydrogen nuclei to produce a single helium nucleus and energy. 
B)  splits a helium nucleus to produce 4 hydrogen nuclei and energy. 
C)  is the mechanism that increases the temperature between the photosphere and corona of the sun. 
D)  is the interactions between protons in Earth s atmosphere that produces auroras. 
E)  produces energy in the core of the sun in the form of gamma-rays, positrons, and neutrinos. 
A)  combines two hydrogen nuclei to produce a single helium nucleus and energy. 
B)  splits a helium nucleus to produce 4 hydrogen nuclei and energy. 
C)  is the mechanism that increases the temperature between the photosphere and corona of the sun. 
D)  is the interactions between protons in Earth s atmosphere that produces auroras. 
E)  produces energy in the core of the sun in the form of gamma-rays, positrons, and neutrinos.

Question 17

Stars are born in

Accepted Answer

A)  reflection nebulae. 
B)  dense molecular clouds. 
C)  HII regions. 
D)  the intercloud medium. 
E)  the local bubble. 
A)  reflection nebulae. 
B)  dense molecular clouds. 
C)  HII regions. 
D)  the intercloud medium. 
E)  the local bubble.

Question 18

____________________ is the resistance of a gas to the flow of radiation.

Accepted Answer

The answer of ____________________ is the resistance of a gas...

Question 19

Helioseismology shows that deeper layers of gas in the sun rotate at different speeds. When different parts of an object rotate at different rates it is called

Accepted Answer

A)  the dynamo effect. 
B)  lagging. 
C)  reconnection. 
D)  differential rotation. 
E)  the Zeeman effect. 
A)  the dynamo effect. 
B)  lagging. 
C)  reconnection. 
D)  differential rotation. 
E)  the Zeeman effect.

Question 20

Due to the dust in the interstellar medium, a distant star will appear to an observer on Earth to be

Accepted Answer

A)  brighter and cooler than it really is. 
B)  brighter and hotter than it really is. 
C)  fainter and cooler than it really is. 
D)  fainter and hotter than it really is. 
E)  unchanged in brightness or apparent color. 
A)  brighter and cooler than it really is. 
B)  brighter and hotter than it really is. 
C)  fainter and cooler than it really is. 
D)  fainter and hotter than it really is. 
E)  unchanged in brightness or apparent color.

The sun makes most of its energy by the CNO cycle.

The pressure of a gas depends on the temperature and density of the gas.

T Tauri stars are believed to be young, high mass main sequence stars.

The diagram below is an HR diagram. The line indicates the location of the main sequence. Which of the five labeled locations on the HR diagram indicates a luminosity and temperature similar to that of a T Tauri star?

If the dust around a protostar radiates most strongly at 30 microns or 30,000 nm, what is the approximate temperature of that dust? Hint: T in K =3,000,000/wavelength in nm.

Which of the following is suggested as the best explanation of the missing solar neutrinos?

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

Hydrostatic equilibrium refers to the balance between weight and pressure.

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 ____ is the nuclear fusion of three helium nuclei to form a carbon nucleus.

Why is there a lower end to the main sequence? Why is there an upper end to the main sequence?

Why do nuclear reactions in a star occur only near its center?

HII regions are found near stars cooler than 25,000 K because large amounts of ultraviolet photons would totally destroy the hydrogen atoms in the gas.

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

The proton-proton chain

Stars are born in

____________________ is the resistance of a gas to the flow of radiation.

Helioseismology shows that deeper layers of gas in the sun rotate at different speeds. When different parts of an object rotate at different rates it is called

Due to the dust in the interstellar medium, a distant star will appear to an observer on Earth to be

Here and Now

Users Guide to the Sky: Patterns and Cycles

The Origin of Modern Astronomy

Light and Telescopes

Sun Light and Sun Atoms

The Terrestrial Planets

The Outer Solar System

Origins of the Solar System and Extrasolar Planets

The Family of Stars

The Deaths of Stars

The Milky Way Galaxy

Galaxies: Normal and Active

Modern Cosmology

Life on Other Worlds

Filters

Exam 10: Structure and Formation of Stars

The sun makes most of its energy by the CNO cycle.

The pressure of a gas depends on the temperature and density of the gas.

T Tauri stars are believed to be young, high mass main sequence stars.

The diagram below is an HR diagram. The line indicates the location of the main sequence. Which of the five labeled locations on the HR diagram indicates a luminosity and temperature similar to that of a T Tauri star?

If the dust around a protostar radiates most strongly at 30 microns or 30,000 nm, what is the approximate temperature of that dust? Hint: T in K =3,000,000/wavelength in nm.

Which of the following is suggested as the best explanation of the missing solar neutrinos?

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

Hydrostatic equilibrium refers to the balance between weight and pressure.

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 ____ is the nuclear fusion of three helium nuclei to form a carbon nucleus.

Why is there a lower end to the main sequence? Why is there an upper end to the main sequence?

Why do nuclear reactions in a star occur only near its center?

HII regions are found near stars cooler than 25,000 K because large amounts of ultraviolet photons would totally destroy the hydrogen atoms in the gas.

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

The proton-proton chain

Stars are born in

____________________ is the resistance of a gas to the flow of radiation.

Helioseismology shows that deeper layers of gas in the sun rotate at different speeds. When different parts of an object rotate at different rates it is called

Due to the dust in the interstellar medium, a distant star will appear to an observer on Earth to be

Here and Now

Users Guide to the Sky: Patterns and Cycles

The Origin of Modern Astronomy

Light and Telescopes

Sun Light and Sun Atoms

The Terrestrial Planets

The Outer Solar System

Origins of the Solar System and Extrasolar Planets

The Family of Stars

The Deaths of Stars

The Milky Way Galaxy

Galaxies: Normal and Active

Modern Cosmology

Life on Other Worlds

Filters