Question 1

Assuming that we can measure the apparent brightness of a star, what does the inverse square law for light allow us to do?

Accepted Answer

A) determine both the star's distance and luminosity from its apparent brightness 
B) calculate the star's surface temperature if we know either its luminosity or its distance 
C) determine the distance to the star from its apparent brightness 
D) calculate the star's luminosity if we know its distance, or calculate its distance if we know its luminosity 
A) determine both the star's distance and luminosity from its apparent brightness 
B) calculate the star's surface temperature if we know either its luminosity or its distance 
C) determine the distance to the star from its apparent brightness 
D) calculate the star's luminosity if we know its distance, or calculate its distance if we know its luminosity

Question 2

Which of the following stellar properties has the greatest range in values?

Accepted Answer

A) radius 
B) surface temperature 
C) luminosity 
D) core temperature 
E) mass 
A) radius 
B) surface temperature 
C) luminosity 
D) core temperature 
E) mass

Question 3

What is the spectral type of a star with strong molecular absorption lines?

Accepted Answer

A) K 
B) M 
C) G 
D) F 
A) K 
B) M 
C) G 
D) F

Question 4

How did astronomers discover the relationship between spectral type and mass for main sequence stars?

Accepted Answer

A) by using computer models of hydrogen fusion and stellar structure 
B) by measuring stellar radii with very powerful telescopes 
C) by measuring the masses and spectral types of main- sequence stars in binary systems 
D) by comparing stars with the same spectral type but different luminosities 
A) by using computer models of hydrogen fusion and stellar structure 
B) by measuring stellar radii with very powerful telescopes 
C) by measuring the masses and spectral types of main- sequence stars in binary systems 
D) by comparing stars with the same spectral type but different luminosities

Question 5

What is the approximate surface temperature of a B star?

Accepted Answer

A) 40,000 K 
B) 6,000 K 
C) 20,000 K 
D) 8,000 K 
A) 40,000 K 
B) 6,000 K 
C) 20,000 K 
D) 8,000 K

Question 6

What is the approximate surface temperature of a star with moderate hydrogen absorption lines and moderate ionized calcium absorption lines?

Accepted Answer

A) 4,500 K 
B) 3,500 K 
C) 6,500 K 
D) 5,500 K 
A) 4,500 K 
B) 3,500 K 
C) 6,500 K 
D) 5,500 K

Question 7

A main- sequence star's luminosity can directly inform us of

Accepted Answer

A) the star's mass. 
B) the star's distance from us. 
C) the rate at which it converts hydrogen to helium. 
D) the star's radius. 
A) the star's mass. 
B) the star's distance from us. 
C) the rate at which it converts hydrogen to helium. 
D) the star's radius.

Question 8

The faintest star visible to the naked eye has an apparent magnitude of about

Accepted Answer

A) - 1. 
B) 10. 
C) 0) 
D) 6) 
E) 1) 
A) - 1. 
B) 10. 
C) 0) 
D) 6) 
E) 1)

Question 9

You observe a star cluster with a main- sequence turn- off point at spectral type G2 (the same spectral type as the Sun). What is the age of this star cluster?

Accepted Answer

A) 10,000 years 
B) 100 billion years 
C) 4)6 billion years 
D) 10 billion years 
E) You also need to know the luminosity class of the turn- off point to determine the age. 
A) 10,000 years 
B) 100 billion years 
C) 4)6 billion years 
D) 10 billion years 
E) You also need to know the luminosity class of the turn- off point to determine the age.

Question 10

On a Hertzsprung- Russell diagram, where would you find stars that have the largest radii?

Accepted Answer

A) upper right 
B) lower right 
C) upper left 
D) lower left 
A) upper right 
B) lower right 
C) upper left 
D) lower left

Question 11

You measure the parallax angle for a star to be 0.5 arcseconds. The distance to this star is

Accepted Answer

A) 5 light- years. 
B) 2 parsecs. 
C) 5 parsecs. 
D) 0)5 light- year. 
E) 0)5 parsec. 
A) 5 light- years. 
B) 2 parsecs. 
C) 5 parsecs. 
D) 0)5 light- year. 
E) 0)5 parsec.

Question 12

A star is observed with a surface temperature of 3,000 K and a luminosity of 105 solar. What is the approximate radius of this star?

Accepted Answer

A) 30 Msun 
B) 0)3 Msun 
C) 3 Msun 
D) The radius cannot be determined. 
A) 30 Msun 
B) 0)3 Msun 
C) 3 Msun 
D) The radius cannot be determined.

Question 13

What is the spectral type of a main sequence star with a luminosity 100 times greater than the sun?

Accepted Answer

A) A 
B) G 
C) M 
D) O 
A) A 
B) G 
C) M 
D) O

Question 14

What is the approximate luminosity of a main- sequence star with weak hydrogen absorption lines and strong absorption lines of ionized calcium?

Accepted Answer

A) About 10-2 solar 
B) About 0.1 solar 
C) About 3 solar 
D) About 1 solar 
A) About 10-2 solar 
B) About 0.1 solar 
C) About 3 solar 
D) About 1 solar

Question 15

If the distance between us and a star is doubled, with everything else remaining the same, its luminosity

Accepted Answer

A) is decreased by a factor of four, and its apparent brightness is decreased by a factor of four. 
B) is decreased by a factor of two, and its apparent brightness is decreased by a factor of two. 
C) remains the same, but its apparent brightness is decreased by a factor of four. 
D) is decreased by a factor of four, but its apparent brightness remains the same. 
E) remains the same, but its apparent brightness is decreased by a factor of two. 
A) is decreased by a factor of four, and its apparent brightness is decreased by a factor of four. 
B) is decreased by a factor of two, and its apparent brightness is decreased by a factor of two. 
C) remains the same, but its apparent brightness is decreased by a factor of four. 
D) is decreased by a factor of four, but its apparent brightness remains the same. 
E) remains the same, but its apparent brightness is decreased by a factor of two.

Question 16

A 10 solar mass star is about ten times more luminous than a 1 solar mass star.

Accepted Answer

A) True 
 B)False

Question 17

The spectral sequence sorts stars according to

Accepted Answer

A) core temperature. 
B) radius. 
C) mass. 
D) surface temperature. 
E) luminosity. 
A) core temperature. 
B) radius. 
C) mass. 
D) surface temperature. 
E) luminosity.

Question 18

What is the common trait of all main- sequence stars?

Accepted Answer

A) They are in the final stage of their lives. 
B) They are all spectral type G. 
C) They generate energy through hydrogen fusion in their core. 
D) They all have approximately the same mass. 
A) They are in the final stage of their lives. 
B) They are all spectral type G. 
C) They generate energy through hydrogen fusion in their core. 
D) They all have approximately the same mass.

Question 19

What is the approximate luminosity of a main- sequence M star?

Accepted Answer

A) 10 solar 
B) 1 solar 
C) 0)01 solar 
D) 10-6 solar 
A) 10 solar 
B) 1 solar 
C) 0)01 solar 
D) 10-6 solar

Question 20

Two stars, Tom and Jerry, have the same spectral type. Tom is luminosity class V and Jerry is luminosity class I. Which star is bigger? Which star is more luminous? Which star has a hotter surface temperature? Explain your answers.

Accepted Answer

Tom is on the main sequence, while Jerry

Assuming that we can measure the apparent brightness of a star, what does the inverse square law for light allow us to do?

Which of the following stellar properties has the greatest range in values?

What is the spectral type of a star with strong molecular absorption lines?

How did astronomers discover the relationship between spectral type and mass for main sequence stars?

What is the approximate surface temperature of a B star?

What is the approximate surface temperature of a star with moderate hydrogen absorption lines and moderate ionized calcium absorption lines?

A main- sequence star's luminosity can directly inform us of

The faintest star visible to the naked eye has an apparent magnitude of about

You observe a star cluster with a main- sequence turn- off point at spectral type G2 (the same spectral type as the Sun). What is the age of this star cluster?

On a Hertzsprung- Russell diagram, where would you find stars that have the largest radii?

You measure the parallax angle for a star to be 0.5 arcseconds. The distance to this star is

A star is observed with a surface temperature of 3,000 K and a luminosity of 105 solar. What is the approximate radius of this star?

What is the spectral type of a main sequence star with a luminosity 100 times greater than the sun?

What is the approximate luminosity of a main- sequence star with weak hydrogen absorption lines and strong absorption lines of ionized calcium?

If the distance between us and a star is doubled, with everything else remaining the same, its luminosity

A 10 solar mass star is about ten times more luminous than a 1 solar mass star.

The spectral sequence sorts stars according to

What is the common trait of all main- sequence stars?

What is the approximate luminosity of a main- sequence M star?

Two stars, Tom and Jerry, have the same spectral type. Tom is luminosity class V and Jerry is luminosity class I. Which star is bigger? Which star is more luminous? Which star has a hotter surface temperature? Explain your answers.

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Star Stuff

The Bizarre Stellar Graveyard

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Exam 12: Surveying the Stars

Assuming that we can measure the apparent brightness of a star, what does the inverse square law for light allow us to do?

Which of the following stellar properties has the greatest range in values?

What is the spectral type of a star with strong molecular absorption lines?

How did astronomers discover the relationship between spectral type and mass for main sequence stars?

What is the approximate surface temperature of a B star?

What is the approximate surface temperature of a star with moderate hydrogen absorption lines and moderate ionized calcium absorption lines?

A main- sequence star's luminosity can directly inform us of

The faintest star visible to the naked eye has an apparent magnitude of about

You observe a star cluster with a main- sequence turn- off point at spectral type G2 (the same spectral type as the Sun). What is the age of this star cluster?

On a Hertzsprung- Russell diagram, where would you find stars that have the largest radii?

You measure the parallax angle for a star to be 0.5 arcseconds. The distance to this star is

A star is observed with a surface temperature of 3,000 K and a luminosity of 105 solar. What is the approximate radius of this star?

What is the spectral type of a main sequence star with a luminosity 100 times greater than the sun?

What is the approximate luminosity of a main- sequence star with weak hydrogen absorption lines and strong absorption lines of ionized calcium?

If the distance between us and a star is doubled, with everything else remaining the same, its luminosity

A 10 solar mass star is about ten times more luminous than a 1 solar mass star.

The spectral sequence sorts stars according to

What is the common trait of all main- sequence stars?

What is the approximate luminosity of a main- sequence M star?

Two stars, Tom and Jerry, have the same spectral type. Tom is luminosity class V and Jerry is luminosity class I. Which star is bigger? Which star is more luminous? Which star has a hotter surface temperature? Explain your answers.

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters