Question 1

In general,the narrower the spectral line of a star:

Accepted Answer

A)  the hotter the star is. 
B)  the bigger the star is. 
C)  the denser the star is. 
D)  the smaller the star is. 
E)  the cooler the star is. 
A)  the hotter the star is. 
B)  the bigger the star is. 
C)  the denser the star is. 
D)  the smaller the star is. 
E)  the cooler the star is. B

Question 2

The ________ magnitude of a star depends directly upon its luminosity and distance.

Accepted Answer

apparent

Question 3

In a binary system,the more massive stars always stay closer to the center of mass and move slower.

Accepted Answer

A) True 
 B)False  True

Question 4

What role does helium play in spectral classification?

Accepted Answer

It is ionized in the hottest O

Question 5

On the H-R diagram,the Sun lies:

Accepted Answer

A)  at the top left. 
B)  at the bottom left. 
C)  at the bottom right. 
D)  about the middle of the main sequence. 
E)  at the top right. 
A)  at the top left. 
B)  at the bottom left. 
C)  at the bottom right. 
D)  about the middle of the main sequence. 
E)  at the top right.

Question 6

For luminosity classification,fat stars have skinny spectral lines.

Accepted Answer

A) True 
 B)False

Question 7

Star A is a main sequence star of spectral type F2 and star B is a white dwarf of spectral type B4.Which statement below is correct?

Accepted Answer

A)  Star A appears brighter than star B. 
B)  Star B appears brighter than star A. 
C)  Star A is hotter than star B. 
D)  Star B is hotter than star A. 
E)  None of the above can be said about these two stars. 
A)  Star A appears brighter than star B. 
B)  Star B appears brighter than star A. 
C)  Star A is hotter than star B. 
D)  Star B is hotter than star A. 
E)  None of the above can be said about these two stars.

Question 8

On the main sequence,almost all stars have radii between about 0.1 and 10 times the Sun.

Accepted Answer

A) True 
 B)False

Question 9

Two red stars have surface temperatures of 3000 K,but Star A's luminosity is about 5% of the Sun's and Star B's luminosity is about 32,000 times the luminosity of the Sun.How much bigger is star B than star A?

Accepted Answer

A)  They are the same size. 
B)  Star B's radius is about 16 times larger than star A's radius. 
C)  Star B's radius is about 800 times larger than star A's radius. 
D)  Star B's radius is about 640,000 times larger than star A's radius. 
E)  This cannot be determined from the information given. 
A)  They are the same size. 
B)  Star B's radius is about 16 times larger than star A's radius. 
C)  Star B's radius is about 800 times larger than star A's radius. 
D)  Star B's radius is about 640,000 times larger than star A's radius. 
E)  This cannot be determined from the information given.

Question 10

What types of observations are necessary to determine the motion of a star through space?

Accepted Answer

To determine the true space motion of a

Question 11

The vast majority of stars near us would fall to the bottom right on the H-R diagram.

Accepted Answer

A) True 
 B)False

Question 12

A nearby star has a parallax of 0.2 arc seconds.What is its distance?

Accepted Answer

A)  0.1 parsec 
B)  0.2 parsec 
C)  0.5 parsec 
D)  5 parsecs 
E)  50 parsecs 
A)  0.1 parsec 
B)  0.2 parsec 
C)  0.5 parsec 
D)  5 parsecs 
E)  50 parsecs

Question 13

If a star appears to move relative to other stars over a one-year period,this motion is due to the star's:

Accepted Answer

A)  transverse motion. 
B)  radial motion. 
C)  parallax shift. 
D)  Doppler shift. 
E)  true space motion. 
A)  transverse motion. 
B)  radial motion. 
C)  parallax shift. 
D)  Doppler shift. 
E)  true space motion.

Question 14

The Hipparcos mission's observations have given us good data on stars out to about:

Accepted Answer

A)  100 light years. 
B)  200 light years. 
C)  200 parsecs. 
D)  1000 light years. 
E)  1000 parsecs. 
A)  100 light years. 
B)  200 light years. 
C)  200 parsecs. 
D)  1000 light years. 
E)  1000 parsecs.

Question 15

The Hipparcos mission's data on parallaxes is useful for stellar distances out to about 200 pc.

Accepted Answer

A) True 
 B)False

Question 16

Having nothing to do with trigonometry,________ parallaxes use the width of absorption lines to estimate the star's luminosity and size and distance.

Accepted Answer

A)  bolometric 
B)  photometric 
C)  spectroscopic 
D)  holographic 
E)  videometric 
A)  bolometric 
B)  photometric 
C)  spectroscopic 
D)  holographic 
E)  videometric

Question 17

The apparent magnitude of the Sun is -26,while Sirius has an apparent magnitude of -1; how much brighter does the Sun appear than Sirius?

Accepted Answer

This is a difference of 25 mag

Question 18

If a star appears to move back and forth relative to other stars over a six-month period,this motion is due to the star's:

Accepted Answer

A)  transverse motion. 
B)  radial motion. 
C)  parallax shift. 
D)  Doppler shift. 
E)  true space motion. 
A)  transverse motion. 
B)  radial motion. 
C)  parallax shift. 
D)  Doppler shift. 
E)  true space motion.

Question 19

Why is the main sequence main? Why are these stars so common?

Accepted Answer

While their masses,luminosities,and temp

Question 20

How can the color index give the star's temperature?

Accepted Answer

Color index requires observing the star'

Exam 17: The Stars: Giants,Dwarfs,and the Main Sequence

In general,the narrower the spectral line of a star:

The ________ magnitude of a star depends directly upon its luminosity and distance.

In a binary system,the more massive stars always stay closer to the center of mass and move slower.

What role does helium play in spectral classification?

On the H-R diagram,the Sun lies:

For luminosity classification,fat stars have skinny spectral lines.

Star A is a main sequence star of spectral type F2 and star B is a white dwarf of spectral type B4.Which statement below is correct?

On the main sequence,almost all stars have radii between about 0.1 and 10 times the Sun.

Two red stars have surface temperatures of 3000 K,but Star A's luminosity is about 5% of the Sun's and Star B's luminosity is about 32,000 times the luminosity of the Sun.How much bigger is star B than star A?

What types of observations are necessary to determine the motion of a star through space?

The vast majority of stars near us would fall to the bottom right on the H-R diagram.

A nearby star has a parallax of 0.2 arc seconds.What is its distance?

If a star appears to move relative to other stars over a one-year period,this motion is due to the star's:

The Hipparcos mission's observations have given us good data on stars out to about:

The Hipparcos mission's data on parallaxes is useful for stellar distances out to about 200 pc.

Having nothing to do with trigonometry,________ parallaxes use the width of absorption lines to estimate the star's luminosity and size and distance.

The apparent magnitude of the Sun is -26,while Sirius has an apparent magnitude of -1; how much brighter does the Sun appear than Sirius?

If a star appears to move back and forth relative to other stars over a six-month period,this motion is due to the star's:

Why is the main sequence main? Why are these stars so common?

How can the color index give the star's temperature?

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information from the Cosmos

Spectroscopy: The Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earth's Sister Planet

Mars: A Near Miss for Life?

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Interstellar Medium: Gas and Dust among the Stars

Star Formation: A Traumatic Birth

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae,Supernovae,and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: A Spiral in Space

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

Life in the Universe: Are We Alone?

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