Question 1

The chemical composition of a star's atmosphere tells us:

Accepted Answer

A)   how much nuclear burning has gone on in the star.
B)   the star's evolutionary stage.
C)   the chemical composition of the cloud from which the star formed.
D)   all of the above

Question 2

In which part of the Milky Way would you find little or no neutral hydrogen,no current star formation,and stars that are older than 10 billion years?

Accepted Answer

A)   the halo
B)   the disk
C)   the galactic center
D)   the solar neighborhood

Question 3

Explain how a standard candle allows you to determine the distance to an object.What is it that you have to measure or know about the standard candle to derive its distance?

Accepted Answer

A standard candle is a star that can be seen at great distances and whose luminosity we know simply by identifying the star (that is,using its period or some other property to recognize it).Its distance is then easily calculated by astronomers by comparing the known luminosity and the measured apparent brightness.

Question 4

Observations of Doppler shifts toward the center of the galaxy show on one side hydrogen clouds are blueshifted while on the other side hydrogen clouds are redshifted.This is the pattern of the rotation velocity of a:

Accepted Answer

A)   cube.
B)   disk.
C)   sphere.
D)   Cannot determine shape from information given. B

Question 5

Which of the following are NOT found in our galaxy's halo?

Accepted Answer

A)   globular clusters
B)   planetary nebulae
C)   RR Lyrae stars
D)   clouds emitting 21-cm radiation

Question 6

Which of the following statements about the history of the Milky Way is correct?

Accepted Answer

A)   The Milky Way was much larger in the past.
B)   The Milky Way evolved from smaller clumps of stars.
C)   The Milky Way has not evolved.
D)   The Milky Way is expanding.

Question 7

Open star clusters primarily inhabit which part of spiral galaxies?

Accepted Answer

A)   disk
B)   halo
C)   bulge
D)   nucleus

Question 8

How do we observe the supermassive black hole at the center of our galaxy?

Accepted Answer

A)   Directly. We can see the dark circle inside its event horizon.
B)   Directly. We can see the light that the black hole emits.
C)   Indirectly. We can observe its gravitational effects on the nearby gas and stars.
D)   We cannot make any observations of the supermassive black hole at the center of our galaxy.

Question 9

Which of the following is closest to the mass of the supermassive black hole at the center of the Milky Way Galaxy?

Accepted Answer

A)   400 solar masses
B)   40,000 solar masses
C)   4 million solar masses
D)   4 billion solar masses

Question 10

Studying standard candles in globular clusters offered the first conclusive proof that our galaxy was much ________ than originally believed.

Accepted Answer

A)   smaller
B)   rounder
C)   larger
D)   flatter

Question 11

The discovery of the period-luminosity relationship for variable stars allowed them to be used as standard candles.Who made this important discovery?

Accepted Answer

A)   Ejnar Hertzsprung
B)   Henrietta Leavitt
C)   Henry Norris Russell
D)   Harlow Shapley

Question 12

In general,open clusters are found in the ________ of the Milky Way; globular clusters are found in the ________ of the Milky Way.

Accepted Answer

A)   disk; disk
B)   halo; halo
C)   disk; halo
D)   halo; disk

Question 13

The distance to the center of the Milky Way cannot be measured directly.Which of the following reasons is the best explanation for this fact?

Accepted Answer

A)   There are no variable stars in the galactic center.
B)   The supermassive black hole emits no light.
C)   Clouds of gas and dust obscure our view.
D)   The center is too bright to measure accurately.

Question 14

Describe the basic scenario that describes the formation and evolution of the Milky Way,including a description of how the halo and disk formed.

Accepted Answer

Several protogalactic fragments began fo...

Question 15

Describe the population of globular star clusters in the Milky Way: how many are there,where do they reside in the Milky Way,and how do their ages and chemical abundances compare to the Sun?

Accepted Answer

The Milky Way contains more than 150 glo...

Question 16

Where would we find the stars with the richest abundance of massive elements? Where would we find those with the smallest amounts of massive elements? Why?

Accepted Answer

Stars with the highest abundance of massive elements are the young stars in the innermost regions of the disk.Stars with the fewest massive elements are the halo stars (such as globular cluster stars).
The reason is that the halo stars formed first when the interstellar medium of the galaxy was the least enriched; the disk stars,particularly in the inner disk where gas is more concentrated,have formed from material that has been (and continues to be)enriched by many generations of star formation.

Question 17

What is the main observational difficulty in observing the shape of the Milky Way?

Accepted Answer

We are seeing it fro...

Question 18

Astronomers use data about stars near the very center of the Milky Way to argue that there must be a supermassive black hole at the center of the galaxy.Describe the method that is used.

Accepted Answer

The stars follow Keplerian orb...

Question 19

If the Large Magellanic Cloud is orbiting the Milky Way in a circular orbit with a speed of 175 km/s and a distance of 165,000 light-years from the center,how long would it take for the Large Magellanic Cloud to complete one orbit around the Milky Way?

Accepted Answer

A)   600 million years
B)   1.8 billion years
C)   3.5 billion years
D)   17 billion years

Question 20

Describe the differences between the ages and chemical abundances of globular and open star clusters.

Accepted Answer

Globular clusters are very old,12 billio...

Exam 15: Our Galaxy: the Milky Way

The chemical composition of a star's atmosphere tells us:

Correct Answer
verified

In which part of the Milky Way would you find little or no neutral hydrogen,no current star formation,and stars that are older than 10 billion years?

Correct Answer
verified

Explain how a standard candle allows you to determine the distance to an object.What is it that you have to measure or know about the standard candle to derive its distance?

Observations of Doppler shifts toward the center of the galaxy show on one side hydrogen clouds are blueshifted while on the other side hydrogen clouds are redshifted.This is the pattern of the rotation velocity of a:

Correct Answer
verified
B

Which of the following are NOT found in our galaxy's halo?

Correct Answer
verified

Which of the following statements about the history of the Milky Way is correct?

Correct Answer
verified

Open star clusters primarily inhabit which part of spiral galaxies?

Correct Answer
verified

How do we observe the supermassive black hole at the center of our galaxy?

Correct Answer
verified

Which of the following is closest to the mass of the supermassive black hole at the center of the Milky Way Galaxy?

Correct Answer
verified

Studying standard candles in globular clusters offered the first conclusive proof that our galaxy was much ________ than originally believed.

Correct Answer
verified

The discovery of the period-luminosity relationship for variable stars allowed them to be used as standard candles.Who made this important discovery?

Correct Answer
verified

In general,open clusters are found in the of the Milky Way; globular clusters are found in the of the Milky Way.

Correct Answer
verified

The distance to the center of the Milky Way cannot be measured directly.Which of the following reasons is the best explanation for this fact?

Correct Answer
verified

Describe the basic scenario that describes the formation and evolution of the Milky Way,including a description of how the halo and disk formed.

Correct Answer
verified
Several protogalactic fragments began fo...
View Answer

Describe the population of globular star clusters in the Milky Way: how many are there,where do they reside in the Milky Way,and how do their ages and chemical abundances compare to the Sun?

Correct Answer
verified
The Milky Way contains more than 150 glo...
View Answer

Where would we find the stars with the richest abundance of massive elements? Where would we find those with the smallest amounts of massive elements? Why?

What is the main observational difficulty in observing the shape of the Milky Way?

Correct Answer
verified
We are seeing it fro...
View Answer

Astronomers use data about stars near the very center of the Milky Way to argue that there must be a supermassive black hole at the center of the galaxy.Describe the method that is used.

Correct Answer
verified
The stars follow Keplerian orb...
View Answer

If the Large Magellanic Cloud is orbiting the Milky Way in a circular orbit with a speed of 175 km/s and a distance of 165,000 light-years from the center,how long would it take for the Large Magellanic Cloud to complete one orbit around the Milky Way?

Correct Answer
verified

Describe the differences between the ages and chemical abundances of globular and open star clusters.

Correct Answer
verified
Globular clusters are very old,12 billio...
View Answer

Exam 15: Our Galaxy: the Milky Way

The chemical composition of a star's atmosphere tells us:

Correct AnswerverifiedShow Answer

In which part of the Milky Way would you find little or no neutral hydrogen,no current star formation,and stars that are older than 10 billion years?

Correct AnswerverifiedShow Answer

Explain how a standard candle allows you to determine the distance to an object.What is it that you have to measure or know about the standard candle to derive its distance?

Observations of Doppler shifts toward the center of the galaxy show on one side hydrogen clouds are blueshifted while on the other side hydrogen clouds are redshifted.This is the pattern of the rotation velocity of a:

Correct AnswerverifiedB

Which of the following are NOT found in our galaxy's halo?

Correct AnswerverifiedShow Answer

Which of the following statements about the history of the Milky Way is correct?

Correct AnswerverifiedShow Answer

Open star clusters primarily inhabit which part of spiral galaxies?

Correct AnswerverifiedShow Answer

How do we observe the supermassive black hole at the center of our galaxy?

Correct AnswerverifiedShow Answer

Which of the following is closest to the mass of the supermassive black hole at the center of the Milky Way Galaxy?

Correct AnswerverifiedShow Answer

Studying standard candles in globular clusters offered the first conclusive proof that our galaxy was much ________ than originally believed.

Correct AnswerverifiedShow Answer

The discovery of the period-luminosity relationship for variable stars allowed them to be used as standard candles.Who made this important discovery?

Correct AnswerverifiedShow Answer

In general,open clusters are found in the ________ of the Milky Way; globular clusters are found in the ________ of the Milky Way.

Correct AnswerverifiedShow Answer

The distance to the center of the Milky Way cannot be measured directly.Which of the following reasons is the best explanation for this fact?

Correct AnswerverifiedShow Answer

Describe the basic scenario that describes the formation and evolution of the Milky Way,including a description of how the halo and disk formed.

Correct AnswerverifiedSeveral protogalactic fragments began fo...View AnswerShow Answer

Describe the population of globular star clusters in the Milky Way: how many are there,where do they reside in the Milky Way,and how do their ages and chemical abundances compare to the Sun?

Correct AnswerverifiedThe Milky Way contains more than 150 glo...View AnswerShow Answer

Where would we find the stars with the richest abundance of massive elements? Where would we find those with the smallest amounts of massive elements? Why?

What is the main observational difficulty in observing the shape of the Milky Way?

Correct AnswerverifiedWe are seeing it fro...View AnswerShow Answer

Astronomers use data about stars near the very center of the Milky Way to argue that there must be a supermassive black hole at the center of the galaxy.Describe the method that is used.

Correct AnswerverifiedThe stars follow Keplerian orb...View AnswerShow Answer

If the Large Magellanic Cloud is orbiting the Milky Way in a circular orbit with a speed of 175 km/s and a distance of 165,000 light-years from the center,how long would it take for the Large Magellanic Cloud to complete one orbit around the Milky Way?

Correct AnswerverifiedShow Answer

Describe the differences between the ages and chemical abundances of globular and open star clusters.

Correct AnswerverifiedGlobular clusters are very old,12 billio...View AnswerShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

In general,open clusters are found in the of the Milky Way; globular clusters are found in the of the Milky Way.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Several protogalactic fragments began fo...
View Answer

Correct Answer
verified
The Milky Way contains more than 150 glo...
View Answer

Correct Answer
verified
We are seeing it fro...
View Answer

Correct Answer
verified
The stars follow Keplerian orb...
View Answer

Correct Answer
verified

Correct Answer
verified
Globular clusters are very old,12 billio...
View Answer