Astronomy 1010 Final Exam | Up to date
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Star A and B have the same luminosity, but star B is 10 times farther from
Earth than star A. How much brighter will star A appear?
A) 1,000 times
B) 100 times
C) 100,000 times
D) 10 times
E) 10,000 times ---------CORRECT ANSWER-----------------B) 100 times
You measure the parallax angle for a star to be 0.1 arcseconds. The
distance to this star is A) 10 parsecs.
B) 0.1 parsec.
C) 10 light-years.
D) 0.1 light-year.
E) impossible to determine. ---------CORRECT ANSWER-----------------A) 10
parsecs
Which of the following statements about apparent and absolute magnitudes
is false ?
A) A star's absolute magnitude is the apparent magnitude it would have if it
were at a distance of 10
parsecs from Earth.
B) The apparent magnitude of a star is dependent upon its luminosity.
C) A star with an apparent magnitude of 1 appears brighter than a star with
an apparent magnitude of 2.
D) The magnitude system that we use now is based on a system used by
the ancient Greeks over 2,000
years ago that classified stars by how bright they appeared. ---------
CORRECT ANSWER-----------------B) the apparent magnitude of a star is
dependent upon its luminosity
,The spectral sequence sorts stars according to
A) mass.
B) luminosity.
C) surface temperature.
D) radius.
E) core temperature ---------CORRECT ANSWER-----------------C) surface
temperature
On a Hertzsprung-Russell diagram, where on the main sequence would
you find stars that have the greatest mass?
A) upper right
B) lower right
C) upper left
D) lower left ---------CORRECT ANSWER-----------------C) upper left
On the main sequence, stars obtain their energy
A) from nuclear fission.
B) from gravitational contraction.
C) from chemical reactions.
D) by converting hydrogen to helium.
E) by converting helium to carbon, nitrogen, and oxygen. ---------CORRECT
ANSWER-----------------D) By converting hydrogen to helium
Which of the following comparisons between low-mass stars and high-
mass main-sequence stars is true?
A) Low-mass stars are cooler and less luminous than high-mass stars.
B) Low-mass stars are cooler but more luminous than high-mass stars.
C) Low-mass stars are hotter and more luminous than high-mass stars.
D) Low-mass stars are hotter but less luminous than high-mass stars.
,E) Low-mass stars have the same temperature and luminosity as high-
mass stars. ---------CORRECT ANSWER-----------------A) Low-mass stars
are cooler and less luminous than high-mass stars.
Which of the following statements about open clusters is true ?
A) All stars in the cluster are approximately the same age.
B) All stars in the cluster have approximately the same mass.
C) All stars in the cluster are approximately the same color.
D) All stars in the cluster will evolve similarly.
E) There is an approximately equal number of all spectral type stars in the
cluster. ---------CORRECT ANSWER-----------------A) All stars in the cluster
are approximately the same age
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?
A) 4.6 billion years
B) 10,000 years
C) 10 billion years
D) 100 billion years
E) You also need to know the luminosity class of the turn-off point to
determine the age. ---------CORRECT ANSWER-----------------C) 10 billion
years
Star X has an apparent magnitude of 3, and star Y has an apparent
magnitude of 8. How do they compare in observed brightness?
A) Star X is 100 times brighter than star Y.
B) Star X is 5 times brighter than star Y.
C) Star Y is 100 times brighter than star X
D) Star Y is 5 times brighter than star X. ---------CORRECT ANSWER--------
---------A) Star X is 100 times brighter than star Y
, Which star has the lowest surface temperature?
A) Sun, G2 V
B) Sirius, A1V
C) Proxima Centauri, M5.5 V
D) Betelgeuse, M2I ---------CORRECT ANSWER-----------------C) Proxima
centauri, M5.5 V
Careful measurements reveal that a star maintains a steady apparent
brightness at most times, except that at precise intervals of 73 hours the
star becomes dimmer for about 2 hours. The change in brightness
alternates between a small change and a large change. The most likely
explanation is that ________.
A) the star is a Cepheid variable
B) the star is a member of an eclipsing binary star system
C) the star is periodically ejecting gas into space every 73 hours
D) the star is a white dwarf ---------CORRECT ANSWER-----------------B)the
star is a member of an eclipsing binary star system
The star Vega has an absolute magnitude of about 4 and an apparent
magnitude of about 0. Based on the definitions of absolute and apparent
magnitude, we can conclude that ________.
A) Vega is nearer than 10 parsecs from Earth
B) Vega's surface temperature is cooler than the Sun
C) Vega's luminosity is less than that of our Sun D) Vega is farther than 10
parsecs from Earth ---------CORRECT ANSWER-----------------A) Vega is
nearer than 10 parsecs from Earth
You observe a star and you want to plot it on an H-R diagram. You will
need to measure all of the following, except the star's ________.
A) distance
C) spectral type
B) apparent brightness
D) mass ---------CORRECT ANSWER-----------------D) mass
Questions and Answers | Verified Answers |
Brand New Version
Star A and B have the same luminosity, but star B is 10 times farther from
Earth than star A. How much brighter will star A appear?
A) 1,000 times
B) 100 times
C) 100,000 times
D) 10 times
E) 10,000 times ---------CORRECT ANSWER-----------------B) 100 times
You measure the parallax angle for a star to be 0.1 arcseconds. The
distance to this star is A) 10 parsecs.
B) 0.1 parsec.
C) 10 light-years.
D) 0.1 light-year.
E) impossible to determine. ---------CORRECT ANSWER-----------------A) 10
parsecs
Which of the following statements about apparent and absolute magnitudes
is false ?
A) A star's absolute magnitude is the apparent magnitude it would have if it
were at a distance of 10
parsecs from Earth.
B) The apparent magnitude of a star is dependent upon its luminosity.
C) A star with an apparent magnitude of 1 appears brighter than a star with
an apparent magnitude of 2.
D) The magnitude system that we use now is based on a system used by
the ancient Greeks over 2,000
years ago that classified stars by how bright they appeared. ---------
CORRECT ANSWER-----------------B) the apparent magnitude of a star is
dependent upon its luminosity
,The spectral sequence sorts stars according to
A) mass.
B) luminosity.
C) surface temperature.
D) radius.
E) core temperature ---------CORRECT ANSWER-----------------C) surface
temperature
On a Hertzsprung-Russell diagram, where on the main sequence would
you find stars that have the greatest mass?
A) upper right
B) lower right
C) upper left
D) lower left ---------CORRECT ANSWER-----------------C) upper left
On the main sequence, stars obtain their energy
A) from nuclear fission.
B) from gravitational contraction.
C) from chemical reactions.
D) by converting hydrogen to helium.
E) by converting helium to carbon, nitrogen, and oxygen. ---------CORRECT
ANSWER-----------------D) By converting hydrogen to helium
Which of the following comparisons between low-mass stars and high-
mass main-sequence stars is true?
A) Low-mass stars are cooler and less luminous than high-mass stars.
B) Low-mass stars are cooler but more luminous than high-mass stars.
C) Low-mass stars are hotter and more luminous than high-mass stars.
D) Low-mass stars are hotter but less luminous than high-mass stars.
,E) Low-mass stars have the same temperature and luminosity as high-
mass stars. ---------CORRECT ANSWER-----------------A) Low-mass stars
are cooler and less luminous than high-mass stars.
Which of the following statements about open clusters is true ?
A) All stars in the cluster are approximately the same age.
B) All stars in the cluster have approximately the same mass.
C) All stars in the cluster are approximately the same color.
D) All stars in the cluster will evolve similarly.
E) There is an approximately equal number of all spectral type stars in the
cluster. ---------CORRECT ANSWER-----------------A) All stars in the cluster
are approximately the same age
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?
A) 4.6 billion years
B) 10,000 years
C) 10 billion years
D) 100 billion years
E) You also need to know the luminosity class of the turn-off point to
determine the age. ---------CORRECT ANSWER-----------------C) 10 billion
years
Star X has an apparent magnitude of 3, and star Y has an apparent
magnitude of 8. How do they compare in observed brightness?
A) Star X is 100 times brighter than star Y.
B) Star X is 5 times brighter than star Y.
C) Star Y is 100 times brighter than star X
D) Star Y is 5 times brighter than star X. ---------CORRECT ANSWER--------
---------A) Star X is 100 times brighter than star Y
, Which star has the lowest surface temperature?
A) Sun, G2 V
B) Sirius, A1V
C) Proxima Centauri, M5.5 V
D) Betelgeuse, M2I ---------CORRECT ANSWER-----------------C) Proxima
centauri, M5.5 V
Careful measurements reveal that a star maintains a steady apparent
brightness at most times, except that at precise intervals of 73 hours the
star becomes dimmer for about 2 hours. The change in brightness
alternates between a small change and a large change. The most likely
explanation is that ________.
A) the star is a Cepheid variable
B) the star is a member of an eclipsing binary star system
C) the star is periodically ejecting gas into space every 73 hours
D) the star is a white dwarf ---------CORRECT ANSWER-----------------B)the
star is a member of an eclipsing binary star system
The star Vega has an absolute magnitude of about 4 and an apparent
magnitude of about 0. Based on the definitions of absolute and apparent
magnitude, we can conclude that ________.
A) Vega is nearer than 10 parsecs from Earth
B) Vega's surface temperature is cooler than the Sun
C) Vega's luminosity is less than that of our Sun D) Vega is farther than 10
parsecs from Earth ---------CORRECT ANSWER-----------------A) Vega is
nearer than 10 parsecs from Earth
You observe a star and you want to plot it on an H-R diagram. You will
need to measure all of the following, except the star's ________.
A) distance
C) spectral type
B) apparent brightness
D) mass ---------CORRECT ANSWER-----------------D) mass
