Question 1

A T Tauri star is at what stage of its stellar evolution?

Accepted Answer

A)  A well-established main-sequence star 
B)  Just before red-giant phase-when variability begins 
C)  At the end of its life-decaying away and cooling 
D)  Protostar-before main-sequence phase 
A)  A well-established main-sequence star 
B)  Just before red-giant phase-when variability begins 
C)  At the end of its life-decaying away and cooling 
D)  Protostar-before main-sequence phase

Question 2

At what stage of its evolutionary life is the Sun?

Accepted Answer

A)  Pre-main-sequence-variable star 
B)  Main-sequence-middle age 
C)  Post-main-sequence-red-giant (cool)phase 
D)  Just before supernova stage (perhaps 5 years)-late evolutionary stage 
A)  Pre-main-sequence-variable star 
B)  Main-sequence-middle age 
C)  Post-main-sequence-red-giant (cool)phase 
D)  Just before supernova stage (perhaps 5 years)-late evolutionary stage

Question 3

The source of a protostar's heat is

Accepted Answer

A)  gravitational energy,released as the star contracts. 
B)  gravitational energy,released as the protostar expands. 
C)  nuclear reactions converting helium to carbon and oxygen in its core. 
D)  nuclear reactions converting hydrogen into helium in its core. 
A)  gravitational energy,released as the star contracts. 
B)  gravitational energy,released as the protostar expands. 
C)  nuclear reactions converting helium to carbon and oxygen in its core. 
D)  nuclear reactions converting hydrogen into helium in its core.

Question 4

Of the three phases of matter-gas,liquid,and solid-solids are by far the simplest to understand.

Accepted Answer

A) True 
 B)False

Question 5

What is the difference between Population I and Population II stars?

Accepted Answer

Ancient stars are said to be metal-poor

Question 6

Planetary nebulae are so-named because

Accepted Answer

A)  these extended objects,often green-colored,looked like planets when first seen by nineteenth-century observers through their telescopes. 
B)  the ejected material is rich in carbon and oxygen,necessary elements for the manufacture of planets in the nebulae surrounding stars. 
C)  they rotate slowly and condense into planetary objects around a central star. 
D)  their spectra appear to be similar to that of the giant gas planets in our own solar system. 
A)  these extended objects,often green-colored,looked like planets when first seen by nineteenth-century observers through their telescopes. 
B)  the ejected material is rich in carbon and oxygen,necessary elements for the manufacture of planets in the nebulae surrounding stars. 
C)  they rotate slowly and condense into planetary objects around a central star. 
D)  their spectra appear to be similar to that of the giant gas planets in our own solar system.

Question 7

A planetary nebula may take millions of years to fade from view from Earth's perspective.

Accepted Answer

A) True 
 B)False

Question 8

Of the following components,which are responsible for the main spectral emission lines found in an emission nebula?

Accepted Answer

A)  Neutral helium,carbon,oxygen,and iron atoms 
B)  Ionized helium atoms and electrons 
C)  Protons,positrons,helium nuclei,and neutrinos 
D)  Hydrogen atoms,protons,and electrons 
A)  Neutral helium,carbon,oxygen,and iron atoms 
B)  Ionized helium atoms and electrons 
C)  Protons,positrons,helium nuclei,and neutrinos 
D)  Hydrogen atoms,protons,and electrons

Question 9

What are evolutionary tracks and how do astronomers use them?

Accepted Answer

The evolutionary track is produced when

Question 10

What is the second most abundant element in the universe (after hydrogen)?

Accepted Answer

A)  Iron 
B)  Carbon 
C)  Nitrogen 
D)  Helium 
A)  Iron 
B)  Carbon 
C)  Nitrogen 
D)  Helium

Question 11

The main energy-generation mechanism in main-sequence stars is

Accepted Answer

A)  core hydrogen fusion. 
B)  shell hydrogen fusion. 
C)  core helium fusion. 
D)  Kelvin-Helmholtz contraction. 
A)  core hydrogen fusion. 
B)  shell hydrogen fusion. 
C)  core helium fusion. 
D)  Kelvin-Helmholtz contraction.

Question 12

The event that marks the end of the main-sequence lifetime of a star is the

Accepted Answer

A)  formation of a nova. 
B)  formation of a planetary nebula. 
C)  end of hydrogen fusion in the core. 
D)  helium flash. 
A)  formation of a nova. 
B)  formation of a planetary nebula. 
C)  end of hydrogen fusion in the core. 
D)  helium flash.

Question 13

The one characteristic that determines a main-sequence star's lifetime is mass.

Accepted Answer

A) True 
 B)False

Question 14

The evolution of a star is controlled mostly by its

Accepted Answer

A)  initial mass. 
B)  location in the galaxy. 
C)  surface temperature. 
D)  chemical composition. 
A)  initial mass. 
B)  location in the galaxy. 
C)  surface temperature. 
D)  chemical composition.

Question 15

The distinct blue color of the nebulosity around stars in young clusters,such as the Pleiades,is caused by

Accepted Answer

A)  light emitted by very hot gas which has been heated by collisions in the interstellar gas. 
B)  preferential scattering of blue starlight by small dust grains in the interstellar material. 
C)  atoms of gas emitting light by fluorescence,having been excited by ultraviolet radiation from hot stars. 
D)  halos caused by refraction of starlight in ice crystals in the nebula,similar to halos seen occasionally in Earth's atmosphere. 
A)  light emitted by very hot gas which has been heated by collisions in the interstellar gas. 
B)  preferential scattering of blue starlight by small dust grains in the interstellar material. 
C)  atoms of gas emitting light by fluorescence,having been excited by ultraviolet radiation from hot stars. 
D)  halos caused by refraction of starlight in ice crystals in the nebula,similar to halos seen occasionally in Earth's atmosphere.

Question 16

What fraction of the measured mass of the universe is helium (as represented by "standard cosmic abundances" in the interstellar medium)?

Accepted Answer

A)  25% 
B)  1% 
C)  8% 
D)  74% 
A)  25% 
B)  1% 
C)  8% 
D)  74%

Question 17

What happens to the helium-rich core of a star after the core runs out of hydrogen?

Accepted Answer

A)  It heats and expands. 
B)  It contracts and heats. 
C)  It cools and contracts. 
D)  It expands and cools. 
A)  It heats and expands. 
B)  It contracts and heats. 
C)  It cools and contracts. 
D)  It expands and cools.

Question 18

What fraction of the measured mass of the universe is hydrogen (as represented by "standard cosmic abundances" in the interstellar medium)?

Accepted Answer

A)  25% 
B)  98% 
C)  1% 
D)  74% 
A)  25% 
B)  98% 
C)  1% 
D)  74%

Question 19

In which phase of a star's life are thermonuclear reactions converting hydrogen into helium in the core of a star?

Accepted Answer

A)  The main-sequence phase 
B)  The horizontal branch phase 
C)  As the star moves up the red-giant branch for the first time 
D)  The protostar phase 
A)  The main-sequence phase 
B)  The horizontal branch phase 
C)  As the star moves up the red-giant branch for the first time 
D)  The protostar phase

Question 20

If a protostar were able to contract (get smaller)without any change to its surface temperature,what would happen to its luminosity?

Accepted Answer

A)  It would decrease,due to the smaller surface area of the protostar. 
B)  It would remain the same because the temperature does not change. 
C)  It is not possible to predict the change in luminosity because other factors are involved. 
D)  It would increase due to the compression of the gas. 
A)  It would decrease,due to the smaller surface area of the protostar. 
B)  It would remain the same because the temperature does not change. 
C)  It is not possible to predict the change in luminosity because other factors are involved. 
D)  It would increase due to the compression of the gas.

A T Tauri star is at what stage of its stellar evolution?

At what stage of its evolutionary life is the Sun?

The source of a protostar's heat is

Of the three phases of matter-gas,liquid,and solid-solids are by far the simplest to understand.

What is the difference between Population I and Population II stars?

Planetary nebulae are so-named because

A planetary nebula may take millions of years to fade from view from Earth's perspective.

Of the following components,which are responsible for the main spectral emission lines found in an emission nebula?

What are evolutionary tracks and how do astronomers use them?

What is the second most abundant element in the universe (after hydrogen)?

The main energy-generation mechanism in main-sequence stars is

The event that marks the end of the main-sequence lifetime of a star is the

The one characteristic that determines a main-sequence star's lifetime is mass.

The evolution of a star is controlled mostly by its

The distinct blue color of the nebulosity around stars in young clusters,such as the Pleiades,is caused by

What fraction of the measured mass of the universe is helium (as represented by "standard cosmic abundances" in the interstellar medium)?

What happens to the helium-rich core of a star after the core runs out of hydrogen?

What fraction of the measured mass of the universe is hydrogen (as represented by "standard cosmic abundances" in the interstellar medium)?

In which phase of a star's life are thermonuclear reactions converting hydrogen into helium in the core of a star?

If a protostar were able to contract (get smaller)without any change to its surface temperature,what would happen to its luminosity?

Predicting the Motions of the Stars, Sun, and Moon

Decoding the Hidden Messages in Starlight

Analyzing Scales and Motions of the Universe

Exploring Our Evolving Solar System

Uncovering Earths Systems

Exploring Terrestrial Surface Processes and Atmospheres

Observing the Dynamic Giant Planets

Looking for Life Beyond Earth

Probing the Dynamic Sun

Observing Properties of Distant Stars

Predicting the Violent End of the Largest Stars

Exploring Our Galaxy

Investigating Other Galaxies

Observing the Evolution of the Universe

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Exam 11: Inferring Patterns in Star Life Cycles

A T Tauri star is at what stage of its stellar evolution?

At what stage of its evolutionary life is the Sun?

The source of a protostar's heat is

Of the three phases of matter-gas,liquid,and solid-solids are by far the simplest to understand.

What is the difference between Population I and Population II stars?

Planetary nebulae are so-named because

A planetary nebula may take millions of years to fade from view from Earth's perspective.

Of the following components,which are responsible for the main spectral emission lines found in an emission nebula?

What are evolutionary tracks and how do astronomers use them?

What is the second most abundant element in the universe (after hydrogen)?

The main energy-generation mechanism in main-sequence stars is

The event that marks the end of the main-sequence lifetime of a star is the

The one characteristic that determines a main-sequence star's lifetime is mass.

The evolution of a star is controlled mostly by its

The distinct blue color of the nebulosity around stars in young clusters,such as the Pleiades,is caused by

What fraction of the measured mass of the universe is helium (as represented by "standard cosmic abundances" in the interstellar medium)?

What happens to the helium-rich core of a star after the core runs out of hydrogen?

What fraction of the measured mass of the universe is hydrogen (as represented by "standard cosmic abundances" in the interstellar medium)?

In which phase of a star's life are thermonuclear reactions converting hydrogen into helium in the core of a star?

If a protostar were able to contract (get smaller)without any change to its surface temperature,what would happen to its luminosity?

Predicting the Motions of the Stars, Sun, and Moon

Decoding the Hidden Messages in Starlight

Analyzing Scales and Motions of the Universe

Exploring Our Evolving Solar System

Uncovering Earths Systems

Exploring Terrestrial Surface Processes and Atmospheres

Observing the Dynamic Giant Planets

Looking for Life Beyond Earth

Probing the Dynamic Sun

Observing Properties of Distant Stars

Predicting the Violent End of the Largest Stars

Exploring Our Galaxy

Investigating Other Galaxies

Observing the Evolution of the Universe

Filters