Question 1

What observations reveal star formation in the Orion nebula?

Accepted Answer

The Orion Nebula, also known as M42, is

Question 2

Opacity is

Accepted Answer

A)  the balance between the pressure and force of gravity inside a star. 
B)  the force that binds protons and neutrons together to form a nucleus. 
C)  the force that binds an electron to the nucleus in an atom. 
D)  a measure of the resistance to the flow of radiation (photons) through a gas. 
E)  the temperature and density at which a gas will undergo thermonuclear fusion. 
A)  the balance between the pressure and force of gravity inside a star. 
B)  the force that binds protons and neutrons together to form a nucleus. 
C)  the force that binds an electron to the nucleus in an atom. 
D)  a measure of the resistance to the flow of radiation (photons) through a gas. 
E)  the temperature and density at which a gas will undergo thermonuclear fusion.

Question 3

Stars with masses less than ____ produce most of their energy via the proton-proton chain.

Accepted Answer

A)  0.01 solar masses 
B)  0.1 solar masses 
C)  1.1 solar masses 
D)  11 solar masses 
E)  110 solar masses 
A)  0.01 solar masses 
B)  0.1 solar masses 
C)  1.1 solar masses 
D)  11 solar masses 
E)  110 solar masses

Question 4

The lowest mass object that can initiate thermonuclear fusion of hydrogen has a mass of about

Accepted Answer

A)  1 solar masses 
B)  80 solar masses 
C)  8 solar masses 
D)  0.08 solar masses 
E)  0.001 solar masses 
A)  1 solar masses 
B)  80 solar masses 
C)  8 solar masses 
D)  0.08 solar masses 
E)  0.001 solar masses

Question 5

Why are interstellar absorption lines so narrow compared to the width of lines which originate in the photopsheres of stars?

Accepted Answer

Interstellar absorption lines are narrow

Question 6

What causes the outward gas pressure that balances the inward pull of gravity in a main sequence star?

Accepted Answer

A)  The rapid outward flow of gas. 
B)  The rapid inward flow of the gas. 
C)  The high temperature of the gas. 
D)  The high density of the gas. 
E)  c and d 
A)  The rapid outward flow of gas. 
B)  The rapid inward flow of the gas. 
C)  The high temperature of the gas. 
D)  The high density of the gas. 
E)  c and d

Question 7

____ are small dark nebulae about 1 light-year in diameter that contain 10 to 1,000 solar masses.

Accepted Answer

A)  HI regions 
B)  HII regions 
C)  Emission nebulae 
D)  Bok globules 
E)  Reflection nebulae 
A)  HI regions 
B)  HII regions 
C)  Emission nebulae 
D)  Bok globules 
E)  Reflection nebulae

Question 8

The lower edge of the Main Sequence band is known as ____ and represents the location in the HR-diagram at which stars begin their lives as main sequence stars.

Accepted Answer

A)  the Coulomb barrier 
B)  hydrostatic equilibrium 
C)  the birth line 
D)  the zero-age main sequence 
E)  the evolutionary track 
A)  the Coulomb barrier 
B)  hydrostatic equilibrium 
C)  the birth line 
D)  the zero-age main sequence 
E)  the evolutionary track

Question 9

The dust in the interstellar medium can make distant stars look redder than they really are.

Accepted Answer

A) True 
 B)False

Question 10

The capture of too few solar neutrinos by Davis in the solar neutrino experiment

Accepted Answer

A)  has been disproved by the results of later experiments. 
B)  can be explained if the sun is not undergoing thermonuclear fusion of hydrogen in its core. 
C)  indicates that the sun s core is much hotter than expected. 
D)  indicates that the sun s core is convective. 
E)  none of the above 
A)  has been disproved by the results of later experiments. 
B)  can be explained if the sun is not undergoing thermonuclear fusion of hydrogen in its core. 
C)  indicates that the sun s core is much hotter than expected. 
D)  indicates that the sun s core is convective. 
E)  none of the above

Question 11

How do measurements of neutrinos from the sun pose a problem for modern astronomy?

Accepted Answer

The measurements of neutrinos from the s

Question 12

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

Accepted Answer

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

Question 13

In the proton-proton chain

Accepted Answer

A)  no neutrinos are produced. 
B)  energy is released because a hydrogen nucleus has a greater mass than a helium nucleus. 
C)  no photons are produced. 
D)  carbon serves as a catalyst for the nuclear reaction. 
E)  energy is produced in the form of gamma rays and the velocity of the created nuclei. 
A)  no neutrinos are produced. 
B)  energy is released because a hydrogen nucleus has a greater mass than a helium nucleus. 
C)  no photons are produced. 
D)  carbon serves as a catalyst for the nuclear reaction. 
E)  energy is produced in the form of gamma rays and the velocity of the created nuclei.

Question 14

The nuclear reactions in a star s core remain under control so long as

Accepted Answer

A)  luminosity depends on mass. 
B)  pressure depends on temperature. 
C)  density depends on mass. 
D)  weight depends on temperature. 
E)  temperature depends on mass. 
A)  luminosity depends on mass. 
B)  pressure depends on temperature. 
C)  density depends on mass. 
D)  weight depends on temperature. 
E)  temperature depends on mass.

Question 15

Protostars are difficult to observe because

Accepted Answer

A)  the protostar stage is very short. 
B)  they are surrounded by cocoons of gas and dust. 
C)  they radiate mainly in the infrared. 
D)  all of the above 
E)  they are all so far away that the light hasn t reached us yet. 
A)  the protostar stage is very short. 
B)  they are surrounded by cocoons of gas and dust. 
C)  they radiate mainly in the infrared. 
D)  all of the above 
E)  they are all so far away that the light hasn t reached us yet.

Question 16

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 17

Some young star clusters contain large numbers of T Tauri stars.

Accepted Answer

A) True 
 B)False

Question 18

What is the difference between the proton-proton chain and the CNO cycle?

Accepted Answer

The answer of What is the difference between the proton-proton...

Question 19

What observations demonstrate the existence of an interstellar medium?

Accepted Answer

The answer of What observations demonstrate the existence of an...

Question 20

The condition of ____________________ means that the force due to gravity pushing down on a layer is exactly equal to the pressure pushing outward on that layer.

Accepted Answer

hydrostati

What observations reveal star formation in the Orion nebula?

Opacity is

Stars with masses less than ____ produce most of their energy via the proton-proton chain.

The lowest mass object that can initiate thermonuclear fusion of hydrogen has a mass of about

Why are interstellar absorption lines so narrow compared to the width of lines which originate in the photopsheres of stars?

What causes the outward gas pressure that balances the inward pull of gravity in a main sequence star?

____ are small dark nebulae about 1 light-year in diameter that contain 10 to 1,000 solar masses.

The lower edge of the Main Sequence band is known as ____ and represents the location in the HR-diagram at which stars begin their lives as main sequence stars.

The dust in the interstellar medium can make distant stars look redder than they really are.

The capture of too few solar neutrinos by Davis in the solar neutrino experiment

How do measurements of neutrinos from the sun pose a problem for modern astronomy?

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

In the proton-proton chain

The nuclear reactions in a star s core remain under control so long as

Protostars are difficult to observe because

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

Some young star clusters contain large numbers of T Tauri stars.

What is the difference between the proton-proton chain and the CNO cycle?

What observations demonstrate the existence of an interstellar medium?

The condition of ____________________ means that the force due to gravity pushing down on a layer is exactly equal to the pressure pushing outward on that layer.

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

What observations reveal star formation in the Orion nebula?

Opacity is

Stars with masses less than ____ produce most of their energy via the proton-proton chain.

The lowest mass object that can initiate thermonuclear fusion of hydrogen has a mass of about

Why are interstellar absorption lines so narrow compared to the width of lines which originate in the photopsheres of stars?

What causes the outward gas pressure that balances the inward pull of gravity in a main sequence star?

____ are small dark nebulae about 1 light-year in diameter that contain 10 to 1,000 solar masses.

The lower edge of the Main Sequence band is known as ____ and represents the location in the HR-diagram at which stars begin their lives as main sequence stars.

The dust in the interstellar medium can make distant stars look redder than they really are.

The capture of too few solar neutrinos by Davis in the solar neutrino experiment

How do measurements of neutrinos from the sun pose a problem for modern astronomy?

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

In the proton-proton chain

The nuclear reactions in a star s core remain under control so long as

Protostars are difficult to observe because

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

Some young star clusters contain large numbers of T Tauri stars.

What is the difference between the proton-proton chain and the CNO cycle?

What observations demonstrate the existence of an interstellar medium?

The condition of ____________________ means that the force due to gravity pushing down on a layer is exactly equal to the pressure pushing outward on that layer.

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