Question 1

What is the ultimate fate of an open star cluster?

Accepted Answer

A)  The shape of the cluster will remain more or less as it is at the present time as the stars in it age and die. 
B)  The stars in the cluster escape one by one until the cluster no longer exists. 
C)  Over time the stars collide and merge, eventually creating a black hole. 
D)  The stars gradually sink toward the center, creating a globular cluster. 
A)  The shape of the cluster will remain more or less as it is at the present time as the stars in it age and die. 
B)  The stars in the cluster escape one by one until the cluster no longer exists. 
C)  Over time the stars collide and merge, eventually creating a black hole. 
D)  The stars gradually sink toward the center, creating a globular cluster.

Question 2

Which of these statements about a globular cluster is NOT true?

Accepted Answer

A)  A globular cluster can contain up to 1 million stars. 
B)  A globular cluster contains only low-mass stars on the main sequence. 
C)  A globular cluster does not contain main-sequence stars. 
D)  A globular cluster has a round shape. 
A)  A globular cluster can contain up to 1 million stars. 
B)  A globular cluster contains only low-mass stars on the main sequence. 
C)  A globular cluster does not contain main-sequence stars. 
D)  A globular cluster has a round shape.

Question 3

The light from a distant cloud of gas and dust looks distinctly red to the unaided eye. When a spectrum is taken, the red color is found to come from a single, bright spectral line. Thus, the red color in this situation is due to

Accepted Answer

A)  interstellar reddening. 
B)  the Balmer spectrum of hydrogen. 
C)  the Doppler effect. 
D)  interstellar reddening, the Balmer spectrum of hydrogen, or the Doppler effect. 
A)  interstellar reddening. 
B)  the Balmer spectrum of hydrogen. 
C)  the Doppler effect. 
D)  interstellar reddening, the Balmer spectrum of hydrogen, or the Doppler effect.

Question 4

In some binary star systems, such as Algol, the less massive star is an old red giant and the more massive star is on the main sequence, evidence that

Accepted Answer

A)  the more massive star captured the other one into orbit sometime after the two stars had formed. 
B)  the more massive star formed later, from a disk of gas surrounding the less massive star. 
C)  mass transfer from one of the stars to the other has occurred. 
D)  stars evolve differently in binary star systems, with less massive stars evolving faster than more massive stars. 
A)  the more massive star captured the other one into orbit sometime after the two stars had formed. 
B)  the more massive star formed later, from a disk of gas surrounding the less massive star. 
C)  mass transfer from one of the stars to the other has occurred. 
D)  stars evolve differently in binary star systems, with less massive stars evolving faster than more massive stars.

Question 5

The mass of a particular giant molecular cloud in interstellar space is 2 million solar masses. What is the mass of the helium in this cloud?

Accepted Answer

A)  40,000 solar masses 
B)  1 million solar masses 
C)  200,000 solar masses 
D)  500,000 solar masses 
A)  40,000 solar masses 
B)  1 million solar masses 
C)  200,000 solar masses 
D)  500,000 solar masses

Question 6

When a star leaves the main sequence and expands toward the red giant region, what is happening inside the star?

Accepted Answer

A)  Helium burning is taking place in a spherical shell just outside the core; the core itself is almost pure carbon and oxygen. 
B)  Hydrogen burning is taking place in a spherical shell just outside the core; the core itself is almost pure helium. 
C)  Hydrogen burning is taking place in a spherical shell just outside the core; the core has not yet started thermonuclear reactions and is still mostly hydrogen. 
D)  Helium is being converted into carbon and oxygen in the core. 
A)  Helium burning is taking place in a spherical shell just outside the core; the core itself is almost pure carbon and oxygen. 
B)  Hydrogen burning is taking place in a spherical shell just outside the core; the core itself is almost pure helium. 
C)  Hydrogen burning is taking place in a spherical shell just outside the core; the core has not yet started thermonuclear reactions and is still mostly hydrogen. 
D)  Helium is being converted into carbon and oxygen in the core.

Question 7

The T Tauri phase of a protostar is characterized by

Accepted Answer

A)  the formation of a planetary nebula. 
B)  strong spectral absorption lines of metals. 
C)  the ejection of substantial amounts of gas from the protostar. 
D)  the helium flash. 
A)  the formation of a planetary nebula. 
B)  strong spectral absorption lines of metals. 
C)  the ejection of substantial amounts of gas from the protostar. 
D)  the helium flash.

Question 8

A brown dwarf is a

Accepted Answer

A)  high-mass star surrounded by an extensive and cool atmosphere of dust and gas. 
B)  star of mass less than about 0.08 solar mass whose core temperature is too low to initiate hydrogen fusion. 
C)  type of asteroid, so named because of its color, which indicates oxidized iron, or rust. 
D)  star in the late phases of evolution following the red giant phase whose temperature is very low-hence the brown color. 
A)  high-mass star surrounded by an extensive and cool atmosphere of dust and gas. 
B)  star of mass less than about 0.08 solar mass whose core temperature is too low to initiate hydrogen fusion. 
C)  type of asteroid, so named because of its color, which indicates oxidized iron, or rust. 
D)  star in the late phases of evolution following the red giant phase whose temperature is very low-hence the brown color.

Question 9

Brown dwarfs and Jovian planets have many similarities. In which of these aspects are they NOT similar?

Accepted Answer

A)  None produce energy by hydrogen fusion. 
B)  They are primarily composed of hydrogen and helium. 
C)  Storms occur in their atmospheres. 
D)  Their cores are not hot enough to fuse deuterium into helium. 
A)  None produce energy by hydrogen fusion. 
B)  They are primarily composed of hydrogen and helium. 
C)  Storms occur in their atmospheres. 
D)  Their cores are not hot enough to fuse deuterium into helium.

Question 10

The instability strip on the H-R diagram

Accepted Answer

A)  includes part of the main sequence. 
B)  is passed through by stars on their way to the helium flash. 
C)  involves only giant stars. 
D)  is where stars erupt as novas and supernovas. 
A)  includes part of the main sequence. 
B)  is passed through by stars on their way to the helium flash. 
C)  involves only giant stars. 
D)  is where stars erupt as novas and supernovas.

Question 11

The light from a distant cloud of gas and dust looks distinctly red to the naked eye. When a spectrum is taken, it is found that many wavelengths that would normally be expected to be in the middle of the spectrum have been shifted into the long-wavelength end of the spectrum. Thus, the red color in this situation is due to

Accepted Answer

A)  interstellar reddening. 
B)  the Balmer spectrum of hydrogen. 
C)  the Doppler effect. 
D)  interstellar reddening, the Balmer spectrum of hydrogen, or the Doppler effect. 
A)  interstellar reddening. 
B)  the Balmer spectrum of hydrogen. 
C)  the Doppler effect. 
D)  interstellar reddening, the Balmer spectrum of hydrogen, or the Doppler effect.

Question 12

What rates of mass loss from red giant stars are typical?

Accepted Answer

A)  10-14 solar mass per year 
B)  10-3 solar mass per year 
C)  Red giant stars do not suffer mass loss. 
D)  10-7 solar mass per year 
A)  10-14 solar mass per year 
B)  10-3 solar mass per year 
C)  Red giant stars do not suffer mass loss. 
D)  10-7 solar mass per year

Question 13

The MOST likely places in which stars and planetary systems are forming in the universe are

Accepted Answer

A)  the centers of galaxies. 
B)  nebulae composed of dense gas and dust. 
C)  regions surrounding quasars. 
D)  the rarified space between galaxies. 
A)  the centers of galaxies. 
B)  nebulae composed of dense gas and dust. 
C)  regions surrounding quasars. 
D)  the rarified space between galaxies.

Question 14

In a list of the 100 nearest stars in the sky, MOST of them are

Accepted Answer

A)  white dwarfs. 
B)  main-sequence stars. 
C)  giants and supergiants. 
D)  brown dwarfs. 
A)  white dwarfs. 
B)  main-sequence stars. 
C)  giants and supergiants. 
D)  brown dwarfs.

Question 15

Which of these statements about open star clusters is TRUE?

Accepted Answer

A)  Open star clusters slowly condense into globular clusters as the stars drive off the remaining interstellar dust and gas. 
B)  One star in an open cluster eventually undergoes a supernova explosion that quickly disperses the other stars. 
C)  As open star clusters slowly condense, their residual rotation spins them into a flat pancake shape and they become spiral galaxies. 
D)  The motions of individual stars are such that all open clusters eventually disperse. 
A)  Open star clusters slowly condense into globular clusters as the stars drive off the remaining interstellar dust and gas. 
B)  One star in an open cluster eventually undergoes a supernova explosion that quickly disperses the other stars. 
C)  As open star clusters slowly condense, their residual rotation spins them into a flat pancake shape and they become spiral galaxies. 
D)  The motions of individual stars are such that all open clusters eventually disperse.

Question 16

The light from a distant cloud of gas and dust looks distinctly red to the unaided eye. When a spectrum is taken, the short wavelengths are all found to be dimmed in intensity compared with the longer wavelengths, which are all more intense. Thus, the red color in this situation is due to

Accepted Answer

A)  interstellar reddening. 
B)  the Balmer spectrum of hydrogen. 
C)  the Doppler effect. 
D)  any one of these three phenomena. 
A)  interstellar reddening. 
B)  the Balmer spectrum of hydrogen. 
C)  the Doppler effect. 
D)  any one of these three phenomena.

Question 17

What is the MOST abundant element in the interstellar medium?

Accepted Answer

A)  carbon 
B)  helium 
C)  oxygen 
D)  hydrogen 
A)  carbon 
B)  helium 
C)  oxygen 
D)  hydrogen

Question 18

Hydrogen in molecular form, H2, is thought to be very abundant in gas clouds in space, but these molecules emit radiation relatively inefficiently since they are symmetrical. Which other molecular element occurs in close association with H2 and is used as a probe for molecular clouds?

Accepted Answer

A)  carbon monoxide (CO) 
B)  methane (CH4) 
C)  water vapor (H2O) 
D)  carbon dioxide (CO2) 
A)  carbon monoxide (CO) 
B)  methane (CH4) 
C)  water vapor (H2O) 
D)  carbon dioxide (CO2)

Question 19

Which of these objects is NOT fully convective?

Accepted Answer

A)  brown dwarf 
B)  low-mass main-sequence star 
C)  Sun 
D)  All objects undergoing fusion are fully convective. 
A)  brown dwarf 
B)  low-mass main-sequence star 
C)  Sun 
D)  All objects undergoing fusion are fully convective.

Question 20

The temperature at which thermonuclear reactions begin to convert helium into carbon (helium burning) is

Accepted Answer

A)  15 million K. 
B)  100 million K. 
C)  1 billion K. 
D)  1 million K. 
A)  15 million K. 
B)  100 million K. 
C)  1 billion K. 
D)  1 million K.

What is the ultimate fate of an open star cluster?

Which of these statements about a globular cluster is NOT true?

The light from a distant cloud of gas and dust looks distinctly red to the unaided eye. When a spectrum is taken, the red color is found to come from a single, bright spectral line. Thus, the red color in this situation is due to

In some binary star systems, such as Algol, the less massive star is an old red giant and the more massive star is on the main sequence, evidence that

The mass of a particular giant molecular cloud in interstellar space is 2 million solar masses. What is the mass of the helium in this cloud?

When a star leaves the main sequence and expands toward the red giant region, what is happening inside the star?

The T Tauri phase of a protostar is characterized by

A brown dwarf is a

Brown dwarfs and Jovian planets have many similarities. In which of these aspects are they NOT similar?

The instability strip on the H-R diagram

What rates of mass loss from red giant stars are typical?

The MOST likely places in which stars and planetary systems are forming in the universe are

In a list of the 100 nearest stars in the sky, MOST of them are

Which of these statements about open star clusters is TRUE?

The light from a distant cloud of gas and dust looks distinctly red to the unaided eye. When a spectrum is taken, the short wavelengths are all found to be dimmed in intensity compared with the longer wavelengths, which are all more intense. Thus, the red color in this situation is due to

What is the MOST abundant element in the interstellar medium?

Hydrogen in molecular form, H₂, is thought to be very abundant in gas clouds in space, but these molecules emit radiation relatively inefficiently since they are symmetrical. Which other molecular element occurs in close association with H₂ and is used as a probe for molecular clouds?

Which of these objects is NOT fully convective?

The temperature at which thermonuclear reactions begin to convert helium into carbon (helium burning) is

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

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Exam 13: The Lives of Stars From Birth Through Middle Age

What is the ultimate fate of an open star cluster?

Which of these statements about a globular cluster is NOT true?

The light from a distant cloud of gas and dust looks distinctly red to the unaided eye. When a spectrum is taken, the red color is found to come from a single, bright spectral line. Thus, the red color in this situation is due to

In some binary star systems, such as Algol, the less massive star is an old red giant and the more massive star is on the main sequence, evidence that

The mass of a particular giant molecular cloud in interstellar space is 2 million solar masses. What is the mass of the helium in this cloud?

When a star leaves the main sequence and expands toward the red giant region, what is happening inside the star?

The T Tauri phase of a protostar is characterized by

A brown dwarf is a

Brown dwarfs and Jovian planets have many similarities. In which of these aspects are they NOT similar?

The instability strip on the H-R diagram

What rates of mass loss from red giant stars are typical?

The MOST likely places in which stars and planetary systems are forming in the universe are

In a list of the 100 nearest stars in the sky, MOST of them are

Which of these statements about open star clusters is TRUE?

The light from a distant cloud of gas and dust looks distinctly red to the unaided eye. When a spectrum is taken, the short wavelengths are all found to be dimmed in intensity compared with the longer wavelengths, which are all more intense. Thus, the red color in this situation is due to

What is the MOST abundant element in the interstellar medium?

Hydrogen in molecular form, H2, is thought to be very abundant in gas clouds in space, but these molecules emit radiation relatively inefficiently since they are symmetrical. Which other molecular element occurs in close association with H2 and is used as a probe for molecular clouds?

Which of these objects is NOT fully convective?

The temperature at which thermonuclear reactions begin to convert helium into carbon (helium burning) is

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Hydrogen in molecular form, H₂, is thought to be very abundant in gas clouds in space, but these molecules emit radiation relatively inefficiently since they are symmetrical. Which other molecular element occurs in close association with H₂ and is used as a probe for molecular clouds?