Question 1

It takes about 10³² hydrogen atoms to make a star.

Accepted Answer

A) True 
 B)False

Question 2

Stage 4 of star formation is when the object can exhibit violent surface activity producing extremely strong protostellar winds.This phase is also called the:

Accepted Answer

A)  protostar phase. 
B)  Herbig-Haro phase. 
C)  brown dwarf phase. 
D)  T Tauri phase. 
E)  protoplanetary nebula phase. 
A)  protostar phase. 
B)  Herbig-Haro phase. 
C)  brown dwarf phase. 
D)  T Tauri phase. 
E)  protoplanetary nebula phase.

Question 3

The birth of stars is a battle between gravity and radiation pressure.

Accepted Answer

A) True 
 B)False

Question 4

During the Hayashi track,a star drops drastically in both ________ and ________.

Accepted Answer

The answer of During the Hayashi track,a star drops drastically...

Question 5

Why does gravitational contraction halt in collapsing protostars?

Accepted Answer

Gravitational contraction heat

Question 6

A typical protostar may be several thousand times more luminous than the Sun.What is the source of this energy?

Accepted Answer

A)  chemical combustion of hydrocarbons 
B)  nuclear fusion in its core 
C)  from the release of gravitational energy as the protostar continues to shrink 
D)  the ionization of the gas as it heats up 
E)  from nearby hot stars or supernovae that have initiated the star formation process 
A)  chemical combustion of hydrocarbons 
B)  nuclear fusion in its core 
C)  from the release of gravitational energy as the protostar continues to shrink 
D)  the ionization of the gas as it heats up 
E)  from nearby hot stars or supernovae that have initiated the star formation process

Question 7

Collisions between galaxies tend to destroy,not create,stars.

Accepted Answer

A) True 
 B)False

Question 8

What kind of variable stars are pre-Main Sequence stars undergoing gravitational contraction and exhibiting erratic changes in their luminosities?

Accepted Answer

A)  R Coronae Borealis 
B)  RR Lyrae 
C)  Cepheid 
D)  T Tauri 
E)  Herbig-Haro 
A)  R Coronae Borealis 
B)  RR Lyrae 
C)  Cepheid 
D)  T Tauri 
E)  Herbig-Haro

Question 9

The Orion Nebula and Tarantula Nebula are examples of ________ Nurseries.

Accepted Answer

The answer of The Orion Nebula and Tarantula Nebula are...

Question 10

The stars found in nebulae like the Orion Nebula probably formed:

Accepted Answer

A)  a few million years ago. 
B)  about 10 million years ago. 
C)  hundreds of millions of years ago. 
D)  billions of years ago. 
E)  at the beginning of the universe. 
A)  a few million years ago. 
B)  about 10 million years ago. 
C)  hundreds of millions of years ago. 
D)  billions of years ago. 
E)  at the beginning of the universe.

Question 11

From stage 4 to stage 7 of star formation,the object plotted on the H-R diagram moves so that:

Accepted Answer

A)  its luminosity decreases, while its temperature increases. 
B)  its luminosity decreases, while its temperature stays the same. 
C)  its luminosity increases, while its temperature increases. 
D)  its luminosity increases, while its temperature stays the same. 
E)  its luminosity stays the same, and its temperature stays the same. 
A)  its luminosity decreases, while its temperature increases. 
B)  its luminosity decreases, while its temperature stays the same. 
C)  its luminosity increases, while its temperature increases. 
D)  its luminosity increases, while its temperature stays the same. 
E)  its luminosity stays the same, and its temperature stays the same.

Question 12

A collapsing cloud fragment that will form a star of one solar mass (like our Sun)has a mass of about:

Accepted Answer

A)  2 solar masses. 
B)  10 solar masses. 
C)  200 solar masses. 
D)  10²⁰ solar masses. 
E)  10⁴⁰ solar masses. 
A)  2 solar masses. 
B)  10 solar masses. 
C)  200 solar masses. 
D)  10²⁰ solar masses. 
E)  10⁴⁰ solar masses.

Question 13

The evolution of a protostar slows significantly as it approaches the main sequence.

Accepted Answer

A) True 
 B)False

Question 14

If the initial interstellar cloud in star formation has a mass sufficient to form hundreds of stars,how does a single star form from it?

Accepted Answer

A)  One star forms at its center and blows the rest of the matter back into space. 
B)  The cloud fragments into smaller clouds and forms many stars at one time. 
C)  One star forms and the rest of the matter goes into making planets, moons, and other objects of a solar system. 
D)  The cloud is disrupted by rotation so that it reduces its mass down to that of a typical star. 
E)  A supernova blows the cloud up and dissipates the majority of the gas. 
A)  One star forms at its center and blows the rest of the matter back into space. 
B)  The cloud fragments into smaller clouds and forms many stars at one time. 
C)  One star forms and the rest of the matter goes into making planets, moons, and other objects of a solar system. 
D)  The cloud is disrupted by rotation so that it reduces its mass down to that of a typical star. 
E)  A supernova blows the cloud up and dissipates the majority of the gas.

Question 15

What is the force that keeps a main sequence star from blowing apart?

Accepted Answer

A)  magnetism 
B)  gravitation 
C)  the strong force 
D)  radiation pressure 
E)  electron degeneration pressure 
A)  magnetism 
B)  gravitation 
C)  the strong force 
D)  radiation pressure 
E)  electron degeneration pressure

Question 16

What is characteristic of a main sequence star?

Accepted Answer

A)  It has a mass less than the Sun's. 
B)  It has rapid rotation and a strong stellar wind. 
C)  Nuclear fusion in the core varies due to the amount of gravitational contraction that occurs and which heavy elements are produced. 
D)  The rate of nuclear energy generated in the hydrogen to helium fusing core equals the rate radiated from the surface. 
E)  All of the above are correct. 
A)  It has a mass less than the Sun's. 
B)  It has rapid rotation and a strong stellar wind. 
C)  Nuclear fusion in the core varies due to the amount of gravitational contraction that occurs and which heavy elements are produced. 
D)  The rate of nuclear energy generated in the hydrogen to helium fusing core equals the rate radiated from the surface. 
E)  All of the above are correct.

Question 17

The most important fact about a cluster of stars that makes them useful for studying star formation is that

Accepted Answer

A)  all the stars formed from the same cloud. 
B)  all the stars formed at about the same time. 
C)  all the stars are at the same distance from Earth. 
D)  all the stars have the same chemical composition. 
E)  all the stars are the same spectral type. 
A)  all the stars formed from the same cloud. 
B)  all the stars formed at about the same time. 
C)  all the stars are at the same distance from Earth. 
D)  all the stars have the same chemical composition. 
E)  all the stars are the same spectral type.

Question 18

Rotation of the protostar helps generate the magnetic fields and bipolar flows.

Accepted Answer

A) True 
 B)False

Question 19

On an H-R diagram,a protostar would be:

Accepted Answer

A)  above and to the right of the main sequence. 
B)  below and to the left of the main sequence. 
C)  below and near the right side of the main sequence. 
D)  above and near the upper left of the main sequence. 
E)  on the main sequence at the extreme lower right. 
A)  above and to the right of the main sequence. 
B)  below and to the left of the main sequence. 
C)  below and near the right side of the main sequence. 
D)  above and near the upper left of the main sequence. 
E)  on the main sequence at the extreme lower right.

Question 20

Star formation may be triggered by ________ which aid gravity through compression of interstellar clouds to greater densities.

Accepted Answer

pressure o

Exam 19: Star Formation: A Traumatic Birth

It takes about 10³² hydrogen atoms to make a star.

Stage 4 of star formation is when the object can exhibit violent surface activity producing extremely strong protostellar winds.This phase is also called the:

The birth of stars is a battle between gravity and radiation pressure.

During the Hayashi track,a star drops drastically in both ________ and ________.

Why does gravitational contraction halt in collapsing protostars?

A typical protostar may be several thousand times more luminous than the Sun.What is the source of this energy?

Collisions between galaxies tend to destroy,not create,stars.

What kind of variable stars are pre-Main Sequence stars undergoing gravitational contraction and exhibiting erratic changes in their luminosities?

The Orion Nebula and Tarantula Nebula are examples of ________ Nurseries.

The stars found in nebulae like the Orion Nebula probably formed:

From stage 4 to stage 7 of star formation,the object plotted on the H-R diagram moves so that:

A collapsing cloud fragment that will form a star of one solar mass (like our Sun)has a mass of about:

The evolution of a protostar slows significantly as it approaches the main sequence.

If the initial interstellar cloud in star formation has a mass sufficient to form hundreds of stars,how does a single star form from it?

What is the force that keeps a main sequence star from blowing apart?

What is characteristic of a main sequence star?

The most important fact about a cluster of stars that makes them useful for studying star formation is that

Rotation of the protostar helps generate the magnetic fields and bipolar flows.

On an H-R diagram,a protostar would be:

Star formation may be triggered by ________ which aid gravity through compression of interstellar clouds to greater densities.

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information from the Cosmos

Spectroscopy: The Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earth's Sister Planet

Mars: A Near Miss for Life?

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants,Dwarfs,and the Main Sequence

The Interstellar Medium: Gas and Dust among the Stars

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae,Supernovae,and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: A Spiral in Space

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

Life in the Universe: Are We Alone?

Filters

During the Hayashi track,a star drops drastically in both and .