Question 1

Why are globular clusters useful for studies of stellar evolution?

Accepted Answer

A)  Their stars span a wide range of masses. 
B)  Their stars are the same age. 
C)  Their stars all have the same composition. 
D)  All of the above. 
A)  Their stars span a wide range of masses. 
B)  Their stars are the same age. 
C)  Their stars all have the same composition. 
D)  All of the above. D

Question 2

Over the course of their hydrogen-fusing lives,stars:

Accepted Answer

A)  move along the main sequence, from left to right. 
B)  remain in nearly the same location on the main sequence. 
C)  move along the main sequence, from right to left. 
D)  move up the red giant branch. 
A)  move along the main sequence, from left to right. 
B)  remain in nearly the same location on the main sequence. 
C)  move along the main sequence, from right to left. 
D)  move up the red giant branch. B

Question 3

Which of the following stellar properties does NOT increase as you trace the main sequence from right to left on an HR diagram?

Accepted Answer

A)  fusion rate 
B)  peak wavelength 
C)  surface area 
D)  temperature 
A)  fusion rate 
B)  peak wavelength 
C)  surface area 
D)  temperature B

Question 4

Suppose that astronomers discover an error in our understanding of Cepheid variable stars,such that stars of a given oscillation period have a smaller luminosity than previously assumed.How would that change the estimated distances to other galaxies?

Accepted Answer

A)  The distance estimates would not change. 
B)  The distance estimates would have greater variation. 
C)  The distance estimates would become larger. 
D)  The distance estimates would become smaller. 
A)  The distance estimates would not change. 
B)  The distance estimates would have greater variation. 
C)  The distance estimates would become larger. 
D)  The distance estimates would become smaller.

Question 5

What was Henrietta Leavitt's most important contribution to astronomy?

Accepted Answer

A)  the spectral typing of stars 
B)  the relationship of stellar spectral type to temperature 
C)  the period-luminosity relation of Cepheid variables 
D)  the discovery of interstellar reddening 
A)  the spectral typing of stars 
B)  the relationship of stellar spectral type to temperature 
C)  the period-luminosity relation of Cepheid variables 
D)  the discovery of interstellar reddening

Question 6

Why does the nature of a star's energy source require a star to change over time?

Accepted Answer

Stars are powered by fusion,wh

Question 7

The figure below shows the apparent position of star A on the sky at two different positions in Earth's orbit.How far away is the star?

Accepted Answer

A)  0.1 parsec 
B)  1 parsec 
C)  10 parsecs 
D)  100 parsecs 
A)  0.1 parsec 
B)  1 parsec 
C)  10 parsecs 
D)  100 parsecs

Question 8

The Hubble Space Telescope has detected galaxies with apparent magnitudes of about 30.Approximately how much fainter are these galaxies than stars with an apparent magnitude of 5?

Accepted Answer

A)  1025 times 
B)  1010 times 
C)  2,500 times 
D)  25 times 
A)  1025 times 
B)  1010 times 
C)  2,500 times 
D)  25 times

Question 9

Star A's spectrum is most intense at 500 nm,while star B's spectrum is most intense at 750 nm.If star A has a temperature of 5,800 K,what is the temperature of star B?

Accepted Answer

A)  13,000 K 
B)  8,700 K 
C)  4,500 K 
D)  3,850 K 
A)  13,000 K 
B)  8,700 K 
C)  4,500 K 
D)  3,850 K

Question 10

On the main sequence,a star's spectral type is ultimately determined by its:

Accepted Answer

A)  distance. 
B)  luminosity. 
C)  composition. 
D)  mass. 
A)  distance. 
B)  luminosity. 
C)  composition. 
D)  mass.

Question 11

How do astronomers construct stellar evolutionary tracks on the HR diagram?

Accepted Answer

Beginning with a computer mode

Question 12

Star A has an apparent magnitude of 5,while star B has an apparent magnitude of 10.If star A is twice as far from Earth as star B,how do the luminosities of the two stars compare?

Accepted Answer

Star A is

Question 13

Why does luminosity increase with stellar mass on the main sequence?

Accepted Answer

More massive stars have more g

Question 14

What will happen when the Sun runs out of hydrogen fuel for fusion?

Accepted Answer

A)  It will explode in a supernova. 
B)  Its internal structure will change. 
C)  It will begin fusing helium. 
D)  It will become a white dwarf. 
A)  It will explode in a supernova. 
B)  Its internal structure will change. 
C)  It will begin fusing helium. 
D)  It will become a white dwarf.

Question 15

What information do you need to calculate the apparent magnitude of a star? What about the absolute magnitude?

Accepted Answer

The apparent magnitude just re

Question 16

What determines the location of a star on the main sequence?

Accepted Answer

A)  age 
B)  mass 
C)  composition 
D)  the star's principal fusion reaction 
A)  age 
B)  mass 
C)  composition 
D)  the star's principal fusion reaction

Question 17

How would astronomers measure the velocity of the star shown in the figure below?

Accepted Answer

A)  through its spectrum 
B)  through a transit 
C)  through its angular velocity across the sky 
D)  through its brightening or dimming with time 
A)  through its spectrum 
B)  through a transit 
C)  through its angular velocity across the sky 
D)  through its brightening or dimming with time

Question 18

If a star is so large that it cannot be resolved by a telescope on (or near)Earth,what quantities must you measure to determine its radius?

Accepted Answer

Its luminosity and temperature

Question 19

Which of the following inputs are necessary for astronomers to compute the stellar evolutionary track of a star?

Accepted Answer

A)  mass and surface temperature 
B)  mass and luminosity 
C)  mass and composition 
D)  luminosity and surface temperature 
A)  mass and surface temperature 
B)  mass and luminosity 
C)  mass and composition 
D)  luminosity and surface temperature

Question 20

An astronomer observes a cluster of stars and constructs an HR diagram like Figure 11.6.What can he or she learn from the region marked "X"?

Accepted Answer

A)  the distance to the cluster 
B)  the radius of the cluster 
C)  the mass of the cluster 
D)  the age of the cluster 
A)  the distance to the cluster 
B)  the radius of the cluster 
C)  the mass of the cluster 
D)  the age of the cluster

Why are globular clusters useful for studies of stellar evolution?

Over the course of their hydrogen-fusing lives,stars:

Which of the following stellar properties does NOT increase as you trace the main sequence from right to left on an HR diagram?

Suppose that astronomers discover an error in our understanding of Cepheid variable stars,such that stars of a given oscillation period have a smaller luminosity than previously assumed.How would that change the estimated distances to other galaxies?

What was Henrietta Leavitt's most important contribution to astronomy?

Why does the nature of a star's energy source require a star to change over time?

The figure below shows the apparent position of star A on the sky at two different positions in Earth's orbit.How far away is the star?

The Hubble Space Telescope has detected galaxies with apparent magnitudes of about 30.Approximately how much fainter are these galaxies than stars with an apparent magnitude of 5?

Star A's spectrum is most intense at 500 nm,while star B's spectrum is most intense at 750 nm.If star A has a temperature of 5,800 K,what is the temperature of star B?

On the main sequence,a star's spectral type is ultimately determined by its:

How do astronomers construct stellar evolutionary tracks on the HR diagram?

Star A has an apparent magnitude of 5,while star B has an apparent magnitude of 10.If star A is twice as far from Earth as star B,how do the luminosities of the two stars compare?

Why does luminosity increase with stellar mass on the main sequence?

What will happen when the Sun runs out of hydrogen fuel for fusion?

What information do you need to calculate the apparent magnitude of a star? What about the absolute magnitude?

What determines the location of a star on the main sequence?

How would astronomers measure the velocity of the star shown in the figure below?

If a star is so large that it cannot be resolved by a telescope on (or near)Earth,what quantities must you measure to determine its radius?

Which of the following inputs are necessary for astronomers to compute the stellar evolutionary track of a star?

An astronomer observes a cluster of stars and constructs an HR diagram like Figure 11.6.What can he or she learn from the region marked "X"?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Nursery of the Stars: the Interstellar Medium and Star Formation

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

Filters

Exam 11: Measuring the Stars: the Main Sequence and Its Meaning

Why are globular clusters useful for studies of stellar evolution?

Over the course of their hydrogen-fusing lives,stars:

Which of the following stellar properties does NOT increase as you trace the main sequence from right to left on an HR diagram?

Suppose that astronomers discover an error in our understanding of Cepheid variable stars,such that stars of a given oscillation period have a smaller luminosity than previously assumed.How would that change the estimated distances to other galaxies?

What was Henrietta Leavitt's most important contribution to astronomy?

Why does the nature of a star's energy source require a star to change over time?

The figure below shows the apparent position of star A on the sky at two different positions in Earth's orbit.How far away is the star?

The Hubble Space Telescope has detected galaxies with apparent magnitudes of about 30.Approximately how much fainter are these galaxies than stars with an apparent magnitude of 5?

Star A's spectrum is most intense at 500 nm,while star B's spectrum is most intense at 750 nm.If star A has a temperature of 5,800 K,what is the temperature of star B?

On the main sequence,a star's spectral type is ultimately determined by its:

How do astronomers construct stellar evolutionary tracks on the HR diagram?

Star A has an apparent magnitude of 5,while star B has an apparent magnitude of 10.If star A is twice as far from Earth as star B,how do the luminosities of the two stars compare?

Why does luminosity increase with stellar mass on the main sequence?

What will happen when the Sun runs out of hydrogen fuel for fusion?

What information do you need to calculate the apparent magnitude of a star? What about the absolute magnitude?

What determines the location of a star on the main sequence?

How would astronomers measure the velocity of the star shown in the figure below?

If a star is so large that it cannot be resolved by a telescope on (or near)Earth,what quantities must you measure to determine its radius?

Which of the following inputs are necessary for astronomers to compute the stellar evolutionary track of a star?

An astronomer observes a cluster of stars and constructs an HR diagram like Figure 11.6.What can he or she learn from the region marked "X"?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Nursery of the Stars: the Interstellar Medium and Star Formation

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

Filters