Question 1

What are some sources of the shock waves that initiate star formation?

Accepted Answer

Emission nebulae produce shock waves,res

Question 2

A cloud fragment too small to collapse into a main sequence star becomes a:

Accepted Answer

A)  white dwarf. 
B)  pulsar. 
C)  T Tauri object. 
D)  brown dwarf. 
E)  planet of another star. 
A)  white dwarf. 
B)  pulsar. 
C)  T Tauri object. 
D)  brown dwarf. 
E)  planet of another star.

Question 3

At what stage of evolution do T Tauri stars occur?

Accepted Answer

A)  just as the collapsing cloud becomes luminous 
B)  when a protostar is on the verge of becoming a main sequence star 
C)  just prior to the protostar stage 
D)  just after the planetary nebula is expelled 
E)  after the star has established itself as a main sequence star 
A)  just as the collapsing cloud becomes luminous 
B)  when a protostar is on the verge of becoming a main sequence star 
C)  just prior to the protostar stage 
D)  just after the planetary nebula is expelled 
E)  after the star has established itself as a main sequence star

Question 4

What are the characteristics of globular cluster stars?

Accepted Answer

A)  no stars as hot as our Sun 
B)  old age and hundreds of thousands to millions of member stars 
C)  no main sequence stars left, with billions of member stars 
D)  a few hundred stars, most still on the main sequence 
E)  hundreds of light years across, with bright OB stars dominant 
A)  no stars as hot as our Sun 
B)  old age and hundreds of thousands to millions of member stars 
C)  no main sequence stars left, with billions of member stars 
D)  a few hundred stars, most still on the main sequence 
E)  hundreds of light years across, with bright OB stars dominant

Question 5

What are some complications that interfere with star formation?

Accepted Answer

A rapidly spinning nebula may

Question 6

Star clusters have been observed within dark nebulae with:

Accepted Answer

A)  optical movies made over decades. 
B)  radio interferometers. 
C)  infrared observations. 
D)  the Chandra X-ray observatory. 
E)  ultraviolet light creating the emission nebulae. 
A)  optical movies made over decades. 
B)  radio interferometers. 
C)  infrared observations. 
D)  the Chandra X-ray observatory. 
E)  ultraviolet light creating the emission nebulae.

Question 7

All globular clusters in our Milky Way are about how old?

Accepted Answer

A)  less than a million years 
B)  ten-fifty million years old 
C)  one to three billion years old 
D)  around ten billion years old 
E)  a variety of ages, from newly born to twenty billions years old 
A)  less than a million years 
B)  ten-fifty million years old 
C)  one to three billion years old 
D)  around ten billion years old 
E)  a variety of ages, from newly born to twenty billions years old

Question 8

Rotation causes the cocoon of dust to flatten into a dusty disk around protostars.

Accepted Answer

A) True 
 B)False

Question 9

Stars form from a collapsing cloud that fragments into smaller and smaller pieces.This process takes about:

Accepted Answer

A)  10,000 years. 
B)  25,000 years. 
C)  100,000 years. 
D)  a few million years. 
E)  100 million years. 
A)  10,000 years. 
B)  25,000 years. 
C)  100,000 years. 
D)  a few million years. 
E)  100 million years.

Question 10

Which of these is NOT a source of the shock waves that lead to protostars?

Accepted Answer

A)  radiation from the OB stars in emission nebulae 
B)  expanding Herbig-Haro objects 
C)  expanding planetary nebula shells 
D)  violent supernovae explosions 
E)  collisions between galaxies 
A)  radiation from the OB stars in emission nebulae 
B)  expanding Herbig-Haro objects 
C)  expanding planetary nebula shells 
D)  violent supernovae explosions 
E)  collisions between galaxies

Question 11

Most stars in the Milky Way probably formed:

Accepted Answer

A)  alone. 
B)  in intergalactic space, then were swept up into the Galaxy. 
C)  in clusters in the Galaxy's spiral arms. 
D)  from planetary nebulae. 
E)  in the galactic Nucleus, then migrated outward later. 
A)  alone. 
B)  in intergalactic space, then were swept up into the Galaxy. 
C)  in clusters in the Galaxy's spiral arms. 
D)  from planetary nebulae. 
E)  in the galactic Nucleus, then migrated outward later.

Question 12

Many of the brightest stars we see are only a few million years old.

Accepted Answer

A) True 
 B)False

Question 13

A typical protostar may be several thousand times more luminous than our Sun.Where does this energy come from?

Accepted Answer

From the release of

Question 14

Which of these is NOT typical of a condensing protostar?

Accepted Answer

A)  magnetic fields producing polar flows 
B)  dusty disks around their equators 
C)  Herbig-Haro objects projecting a light year out in space 
D)  fusion of helium into carbon in their cores 
E)  more infrared than visible light given off from the cocoon of dust around the star 
A)  magnetic fields producing polar flows 
B)  dusty disks around their equators 
C)  Herbig-Haro objects projecting a light year out in space 
D)  fusion of helium into carbon in their cores 
E)  more infrared than visible light given off from the cocoon of dust around the star

Question 15

Since brown dwarfs cannot ignite hydrogen fusion,how might we hope to spot them? What role does deuterium play in this?

Accepted Answer

In the Kelvin-Helmholtz contraction,they

Question 16

In general,the greater the mass of the protostar,the ________ it contracts to the main sequence.

Accepted Answer

The answer of In general,the greater the mass of the...

Question 17

What do we mean by the term molecular clouds? Why do they exist? How can observation of their properties yield clues to the processes of stellar formation?

Accepted Answer

Molecular clouds are very cool interstel

Question 18

As a protostar evolves from stage 4 to stage 6,it gets hotter but much less bright.

Accepted Answer

A) True 
 B)False

Question 19

A cloud fragment too small to form a star becomes:

Accepted Answer

A)  a red giant. 
B)  a black hole. 
C)  a brown dwarf. 
D)  a T Tauri object. 
E)  a Herbig Haro object. 
A)  a red giant. 
B)  a black hole. 
C)  a brown dwarf. 
D)  a T Tauri object. 
E)  a Herbig Haro object.

Question 20

A newly formed protostar will radiate primarily at which wavelength?

Accepted Answer

A)  visible light 
B)  X-ray 
C)  infrared 
D)  ultraviolet 
E)  radio 
A)  visible light 
B)  X-ray 
C)  infrared 
D)  ultraviolet 
E)  radio

Exam 19: Star Formation: A Traumatic Birth

What are some sources of the shock waves that initiate star formation?

A cloud fragment too small to collapse into a main sequence star becomes a:

At what stage of evolution do T Tauri stars occur?

What are the characteristics of globular cluster stars?

What are some complications that interfere with star formation?

Star clusters have been observed within dark nebulae with:

All globular clusters in our Milky Way are about how old?

Rotation causes the cocoon of dust to flatten into a dusty disk around protostars.

Stars form from a collapsing cloud that fragments into smaller and smaller pieces.This process takes about:

Which of these is NOT a source of the shock waves that lead to protostars?

Most stars in the Milky Way probably formed:

Many of the brightest stars we see are only a few million years old.

A typical protostar may be several thousand times more luminous than our Sun.Where does this energy come from?

Which of these is NOT typical of a condensing protostar?

Since brown dwarfs cannot ignite hydrogen fusion,how might we hope to spot them? What role does deuterium play in this?

In general,the greater the mass of the protostar,the ________ it contracts to the main sequence.

What do we mean by the term molecular clouds? Why do they exist? How can observation of their properties yield clues to the processes of stellar formation?

As a protostar evolves from stage 4 to stage 6,it gets hotter but much less bright.

A cloud fragment too small to form a star becomes:

A newly formed protostar will radiate primarily at which wavelength?

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?

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