Question 1

There is a main-sequence mass-luminosity relation because

Accepted Answer

A)  helium fusion produces carbon. 
B)  stars expand when they become giants. 
C)  more massive stars support their larger weight by making more energy. 
D)  the helium flash occurs in degenerate matter. 
E)  all stars on the main sequence have about the same radius. 
A)  helium fusion produces carbon. 
B)  stars expand when they become giants. 
C)  more massive stars support their larger weight by making more energy. 
D)  the helium flash occurs in degenerate matter. 
E)  all stars on the main sequence have about the same radius.

Question 2

What is the lifetime of a 10-solar-mass star on the main sequence?

Accepted Answer

A)  3.2 × 107 years 
B)  320 years 
C)  3.2 × 1012 years 
D)  1 × 109 years 
E)  1 × 1011 years 
A)  3.2 × 107 years 
B)  320 years 
C)  3.2 × 1012 years 
D)  1 × 109 years 
E)  1 × 1011 years

Question 3

Which of the following is NOT evidence of the existence of an interstellar medium?

Accepted Answer

A)  extinction of light from distant stars 
B)  very narrow calcium absorption lines in the spectra of O and B stars 
C)  reddening of more distant stars 
D)  dark cloud silhouetted against background stars 
E)  molecular absorption lines in the spectra of cool stars 
A)  extinction of light from distant stars 
B)  very narrow calcium absorption lines in the spectra of O and B stars 
C)  reddening of more distant stars 
D)  dark cloud silhouetted against background stars 
E)  molecular absorption lines in the spectra of cool stars

Question 4

ZAMS is an acronym for ______________________________.

Accepted Answer

Zero Age M

Question 5

The above visual wavelength image of the Trapezium cluster shows _________.

Accepted Answer

A)  main sequence and protostars 
B)  protostars and YSOs 
C)  YSOs and ZAMS 
D)  ZAMS and protostars 
A)  main sequence and protostars 
B)  protostars and YSOs 
C)  YSOs and ZAMS 
D)  ZAMS and protostars

Question 6

More massive stars have more weight to support, so these stars are more luminous.

Accepted Answer

A) True 
 B)False

Question 7

What is the difference between the proton-proton chain and the CNO cycle?

Accepted Answer

The proton-proton chain occurs at temper

Question 8

The average star spends ________ of its lifetime on the main sequence.

Accepted Answer

A)  1% 
B)  2% 
C)  10% 
D)  20% 
E)  90% 
A)  1% 
B)  2% 
C)  10% 
D)  20% 
E)  90%

Question 9

The interstellar medium is made of ___ % dust and ___ % gas.

Accepted Answer

A)  1, 99 
B)  0, 100 
C)  100, 0 
D)  5, 95 
A)  1, 99 
B)  0, 100 
C)  100, 0 
D)  5, 95

Question 10

Due to the dust in the interstellar medium, a distant star will appear to an observer on Earth to be

Accepted Answer

A)  brighter and cooler than it really is. 
B)  brighter and hotter than it really is. 
C)  fainter and cooler than it really is. 
D)  fainter and hotter than it really is. 
E)  unchanged in brightness or apparent color. 
A)  brighter and cooler than it really is. 
B)  brighter and hotter than it really is. 
C)  fainter and cooler than it really is. 
D)  fainter and hotter than it really is. 
E)  unchanged in brightness or apparent color.

Question 11

____________________ is the resistance of a gas to the flow of radiation.

Accepted Answer

The answer of ____________________ is the resistance of a gas...

Question 12

The dust in the interstellar medium can make distant stars look redder than they really are.

Accepted Answer

A) True 
 B)False

Question 13

YSOs are in hydrostatic equilibrium.

Accepted Answer

A) True 
 B)False

Question 14

The central cores of which type of star is the lowest temperature?

Accepted Answer

A)  protostars. 
B)  massive main-sequence stars. 
C)  white dwarf stars. 
A)  protostars. 
B)  massive main-sequence stars. 
C)  white dwarf stars.

Question 15

In the Herbig-Haro object shown above, the Herbig-Haro is the ___________.

Accepted Answer

A)  red jet 
B)  white/blue colored interstellar medium the red jet runs into 
C)  dusty disk containing a newborn star and the red jet 
D)  All of these choices are correct. 
A)  red jet 
B)  white/blue colored interstellar medium the red jet runs into 
C)  dusty disk containing a newborn star and the red jet 
D)  All of these choices are correct.

Question 16

The pressure of a gas depends on the temperature and density of the gas.

Accepted Answer

A) True 
 B)False

Question 17

Why are massive stars more luminous than low mass stars? That is, why is there a mass-luminosity relation?

Accepted Answer

​T o understand the mass-luminosity rela

Question 18

The above reactions are of the ___________________.

Accepted Answer

A)  proton-proton fusion chain 
B)  hydrogen-hydrogen fusion chain 
C)  CNO cycle 
D)  All of the other choices are correct. 
A)  proton-proton fusion chain 
B)  hydrogen-hydrogen fusion chain 
C)  CNO cycle 
D)  All of the other choices are correct.

Question 19

Ionization from the ____________________ star in the Orion nebula makes it ____________________ brightly.

Accepted Answer

The answer of Ionization from the ____________________ star in the...

Question 20

What is the correct fraction of dust to gas in the interstellar medium?

Accepted Answer

A)  1/99 
B)  10/90 
C)  50/50 
D)  90/10 
A)  1/99 
B)  10/90 
C)  50/50 
D)  90/10

There is a main-sequence mass-luminosity relation because

What is the lifetime of a 10-solar-mass star on the main sequence?

Which of the following is NOT evidence of the existence of an interstellar medium?

ZAMS is an acronym for ______________________________.

The above visual wavelength image of the Trapezium cluster shows _________.

More massive stars have more weight to support, so these stars are more luminous.

What is the difference between the proton-proton chain and the CNO cycle?

The average star spends ________ of its lifetime on the main sequence.

The interstellar medium is made of _ % dust and _ % gas.

Due to the dust in the interstellar medium, a distant star will appear to an observer on Earth to be

____________________ is the resistance of a gas to the flow of radiation.

The dust in the interstellar medium can make distant stars look redder than they really are.

YSOs are in hydrostatic equilibrium.

The central cores of which type of star is the lowest temperature?

In the Herbig-Haro object shown above, the Herbig-Haro is the ___________.

The pressure of a gas depends on the temperature and density of the gas.

Why are massive stars more luminous than low mass stars? That is, why is there a mass-luminosity relation?

The above reactions are of the ___________________.

Ionization from the star in the Orion nebula makes it brightly.

What is the correct fraction of dust to gas in the interstellar medium?

Here and Now

A Users Guide to the Sky

Cycles of the Sun and Moon

The Origin of Modern Astronomy

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Deaths of Stars

Neutron Stars and Black Holes

The Milky Way Galaxy

Galaxies: Normal and Active

Modern Cosmology

Origin of the Solar System and Extrasolar Planets

Earth and Moon: Bases for Comparative Planetology

Mercury, Venus, and Mars

The Outer Solar System

Meteorites, Asteroids, and Comets

Astrobiology: Life on Other Worlds

Filters

Exam 9: The Formation and Structure of Stars

There is a main-sequence mass-luminosity relation because

What is the lifetime of a 10-solar-mass star on the main sequence?

Which of the following is NOT evidence of the existence of an interstellar medium?

ZAMS is an acronym for ______________________________.

The above visual wavelength image of the Trapezium cluster shows _________.

More massive stars have more weight to support, so these stars are more luminous.

What is the difference between the proton-proton chain and the CNO cycle?

The average star spends ________ of its lifetime on the main sequence.

The interstellar medium is made of ___ % dust and ___ % gas.

Due to the dust in the interstellar medium, a distant star will appear to an observer on Earth to be

____________________ is the resistance of a gas to the flow of radiation.

The dust in the interstellar medium can make distant stars look redder than they really are.

YSOs are in hydrostatic equilibrium.

The central cores of which type of star is the lowest temperature?

In the Herbig-Haro object shown above, the Herbig-Haro is the ___________.

The pressure of a gas depends on the temperature and density of the gas.

Why are massive stars more luminous than low mass stars? That is, why is there a mass-luminosity relation?

The above reactions are of the ___________________.

Ionization from the ____________________ star in the Orion nebula makes it ____________________ brightly.

What is the correct fraction of dust to gas in the interstellar medium?

Here and Now

A Users Guide to the Sky

Cycles of the Sun and Moon

The Origin of Modern Astronomy

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Deaths of Stars

Neutron Stars and Black Holes

The Milky Way Galaxy

Galaxies: Normal and Active

Modern Cosmology

Origin of the Solar System and Extrasolar Planets

Earth and Moon: Bases for Comparative Planetology

Mercury, Venus, and Mars

The Outer Solar System

Meteorites, Asteroids, and Comets

Astrobiology: Life on Other Worlds

Filters

The interstellar medium is made of _ % dust and _ % gas.

Ionization from the star in the Orion nebula makes it brightly.