Question 1

Why are dark dust clouds largely misnamed?

Accepted Answer

A)  They contain much more gas than dust. 
B)  It is ice, not dust, which make them look dark. 
C)  Dust clouds do radiate energy, but not as much light as the stars do. 
D)  The cloud is an illusion, for the dust is evenly distributed around the Galaxy. 
E)  All of the above are correct. 
A)  They contain much more gas than dust. 
B)  It is ice, not dust, which make them look dark. 
C)  Dust clouds do radiate energy, but not as much light as the stars do. 
D)  The cloud is an illusion, for the dust is evenly distributed around the Galaxy. 
E)  All of the above are correct.

Question 2

Why do new stars generally form in close proximity?

Accepted Answer

As a gas cloud collapses, it breaks into

Question 3

Contrast the appearance of the H- R diagrams of a young open and old globular cluster.

Accepted Answer

In a young cluster, the main sequence is

Question 4

Dark nebulae are opaque to all wavelengths of electromagnetic radiation.

Accepted Answer

A) True 
 B)False

Question 5

On an H- R diagram, a protostar would be

Accepted Answer

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

Question 6

What is the primary visible color of an emission nebula?

Accepted Answer

A)  red due to the Ha line of hydrogen 
B)  black, because of dust 
C)  blue due to ionized helium atoms 
D)  blue from the scattering of light off the tiny molecules 
E)  red because of reddening by dust 
A)  red due to the Ha line of hydrogen 
B)  black, because of dust 
C)  blue due to ionized helium atoms 
D)  blue from the scattering of light off the tiny molecules 
E)  red because of reddening by dust

Question 7

Almost all of the complex molecules found in space are based on atoms.

Accepted Answer

A)  silicon 
B)  carbon 
C)  oxygen 
D)  hydrogen 
E)  iron 
A)  silicon 
B)  carbon 
C)  oxygen 
D)  hydrogen 
E)  iron

Question 8

The spectra of interstellar gas clouds show that they have the same basic composition as

Accepted Answer

A)  asteroids. 
B)  Earth's atmosphere. 
C)  interstellar dust. 
D)  stars. 
E)  the Martian polar caps. 
A)  asteroids. 
B)  Earth's atmosphere. 
C)  interstellar dust. 
D)  stars. 
E)  the Martian polar caps.

Question 9

What are thought to be some possible causes of triggering the contraction of an interstellar cloud?

Accepted Answer

The shockwave from the formati

Question 10

Most molecules found in the interstellar medium are based on carbon.

Accepted Answer

A) True 
 B)False

Question 11

Bright blue stars are typical of young star clusters.

Accepted Answer

The answer of Bright blue stars are typical of young...

Question 12

Contrast the chemical composition of interstellar gas with that of interstellar dust.

Accepted Answer

Gas is almost all hydrogen and

Question 13

The average temperature of the typical dark dust cloud is about

Accepted Answer

A)  0 K. 
B)  2.73 K. 
C)  100 K. 
D)  3,000 K. 
E)  6,000 K. 
A)  0 K. 
B)  2.73 K. 
C)  100 K. 
D)  3,000 K. 
E)  6,000 K.

Question 14

A photosphere appears on a protostar near the end of stage

Accepted Answer

A)  1. 
B)  2. 
C)  3. 
D)  6. 
E)  7. 
A)  1. 
B)  2. 
C)  3. 
D)  6. 
E)  7.

Question 15

What information does 21- cm radiation provide about the gas clouds?

Accepted Answer

A)  their density 
B)  their motion 
C)  their temperature 
D)  their distribution 
E)  all of the above 
A)  their density 
B)  their motion 
C)  their temperature 
D)  their distribution 
E)  all of the above

Question 16

What happens to light passing through even thin clouds of dust?

Accepted Answer

A)  Even a little can completely block all light, such as the Horsehead Nebula. 
B)  It dims and reddens the light of all more distant stars. 
C)  Its motion causes the light of stars beyond to twinkle. 
D)  The light that passes through them is blueshifted due to the cloud's approach. 
E)  Its motion causes all light to be redshifted as it passes through these clouds. 
A)  Even a little can completely block all light, such as the Horsehead Nebula. 
B)  It dims and reddens the light of all more distant stars. 
C)  Its motion causes the light of stars beyond to twinkle. 
D)  The light that passes through them is blueshifted due to the cloud's approach. 
E)  Its motion causes all light to be redshifted as it passes through these clouds.

Question 17

What is the critical temperature for stage 7; why?

Accepted Answer

The core must reach 15 million

Question 18

What is the Local Bubble?

Accepted Answer

The Local Bubble is a large region, appr

Question 19

What two things are needed to create an emission nebula?

Accepted Answer

A)  interstellar gas and dust 
B)  hydrogen fusion and helium ionization 
C)  hydrogen gas and carbon dust 
D)  hot stars and interstellar gas, particularly hydrogen 
E)  cool stars and much interstellar dust 
A)  interstellar gas and dust 
B)  hydrogen fusion and helium ionization 
C)  hydrogen gas and carbon dust 
D)  hot stars and interstellar gas, particularly hydrogen 
E)  cool stars and much interstellar dust

Question 20

While ionized hydrogen glows bright red, neutral hydrogen is transparent visibly and best studied with 21- cm radio waves.

Accepted Answer

A) True 
 B)False

Why are dark dust clouds largely misnamed?

Why do new stars generally form in close proximity?

Contrast the appearance of the H- R diagrams of a young open and old globular cluster.

Dark nebulae are opaque to all wavelengths of electromagnetic radiation.

On an H- R diagram, a protostar would be

What is the primary visible color of an emission nebula?

Almost all of the complex molecules found in space are based on atoms.

The spectra of interstellar gas clouds show that they have the same basic composition as

What are thought to be some possible causes of triggering the contraction of an interstellar cloud?

Most molecules found in the interstellar medium are based on carbon.

Bright blue stars are typical of young star clusters.

Contrast the chemical composition of interstellar gas with that of interstellar dust.

The average temperature of the typical dark dust cloud is about

A photosphere appears on a protostar near the end of stage

What information does 21- cm radiation provide about the gas clouds?

What happens to light passing through even thin clouds of dust?

What is the critical temperature for stage 7; why?

What is the Local Bubble?

What two things are needed to create an emission nebula?

While ionized hydrogen glows bright red, neutral hydrogen is transparent visibly and best studied with 21- cm radio waves.

Charting the Heavens: the Foundations of Astronomy

The Copernican Revolution: the Birth of Modern Science

Light and Matter: the Inner Workings of the Cosmos

Telescopes: the Tools of Astronomy

The Solar System: Interplanetary Matter and the Birth of the Planets

Earth and Its Moon: Our Cosmic Backyard

The Terrestrial Planets: a Study in Contrasts

The Jovian Planets: Giants of the Solar System

Moons, Rings, and Plutoids: Small Worlds Among Giants

The Sun: Our Parent Star

Measuring the Stars: Giants, Dwarfs, and the Main Sequence

Stellar Evolution: the Lives and Deaths of Stars

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: a Spiral in Space

Normal and Active Galaxies: Building Blocks of the Universe

Hubbles Law and Dark Matter: the Large-Scale Structure of the Cosmos

Cosmology: the Big Bang and the Fate of the Universe

Life in the Universe: Are We Alone

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Exam 12: The Interstellar Medium: Star Formation in the Milky Way

Why are dark dust clouds largely misnamed?

Why do new stars generally form in close proximity?

Contrast the appearance of the H- R diagrams of a young open and old globular cluster.

Dark nebulae are opaque to all wavelengths of electromagnetic radiation.

On an H- R diagram, a protostar would be

What is the primary visible color of an emission nebula?

Almost all of the complex molecules found in space are based on atoms.

The spectra of interstellar gas clouds show that they have the same basic composition as

What are thought to be some possible causes of triggering the contraction of an interstellar cloud?

Most molecules found in the interstellar medium are based on carbon.

Bright blue stars are typical of young star clusters.

Contrast the chemical composition of interstellar gas with that of interstellar dust.

The average temperature of the typical dark dust cloud is about

A photosphere appears on a protostar near the end of stage

What information does 21- cm radiation provide about the gas clouds?

What happens to light passing through even thin clouds of dust?

What is the critical temperature for stage 7; why?

What is the Local Bubble?

What two things are needed to create an emission nebula?

While ionized hydrogen glows bright red, neutral hydrogen is transparent visibly and best studied with 21- cm radio waves.

Charting the Heavens: the Foundations of Astronomy

The Copernican Revolution: the Birth of Modern Science

Light and Matter: the Inner Workings of the Cosmos

Telescopes: the Tools of Astronomy

The Solar System: Interplanetary Matter and the Birth of the Planets

Earth and Its Moon: Our Cosmic Backyard

The Terrestrial Planets: a Study in Contrasts

The Jovian Planets: Giants of the Solar System

Moons, Rings, and Plutoids: Small Worlds Among Giants

The Sun: Our Parent Star

Measuring the Stars: Giants, Dwarfs, and the Main Sequence

Stellar Evolution: the Lives and Deaths of Stars

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: a Spiral in Space

Normal and Active Galaxies: Building Blocks of the Universe

Hubbles Law and Dark Matter: the Large-Scale Structure of the Cosmos

Cosmology: the Big Bang and the Fate of the Universe

Life in the Universe: Are We Alone

Filters