Astro 7N Exam 2 Solved 100%
Correct!!
A high luminosity star - Answer Emits more light than a low-luminosity star
If a red giant appears the same brightness as a red main sequence star, which one
is farther away? - Answer The red giant
The heaviest nuclei of all are formed... - Answer During a supernova explosion
Hydrogen-2 + proton = ____ + energy: - Answer Helium-3
Which of the following has the smallest radius? - Answer Neutron star
Why does the main sequence part of a star's life end? - Answer The hydrogen in the
core is exhausted.
Which of the following will have the shortest lifetime on the main sequence? -
Answer Main sequence star with surface temperature 20000 K
Many of the brightest 100 stars viewed from Earth are not on the main sequence
(even though most stars are) because... - Answer The most luminous stars are
giants and supergiants that have already finished their main sequence lifetimes
A 2-solar-mass main sequence star is the same distance as a 0.2-solar-mass main
sequence star. Which star appears brighter? - Answer The 2 solar mass main
sequence star appears brighter
The temperature of the photosphere of the Sun is closest to... - Answer 6000 Kelvin
An estimate of the number of communicating/technological civilizations that we
expect in our Galaxy would be a larger number if... - Answer The average number of
planets that could support life for each star were larger
If the sun had twice its mass, then which of these planets would be in its habitable
zone? - Answer Jupiter
how do astronomers measure the temperature of stars? - Answer By looking at
which absorption lines are present in the star's spectrum.
The largest fraction of nearby stars (e.g. within 100 light years) are... - Answer Red
main sequence stars
The parallax angle of a nearby star is measured to be 0.02 arcseconds. What is the
distance to the star? - Answer 50 parsecs
, Which of the following is the sequence of events for a 40-solar mass star (one of the
most-massive stars)? - Answer Stellar nursery, protostar, blue star on main
sequence, Type 2 supernova, black hole
Star A is 9 times as luminous as Star B. The two stars appear the same brightness.
What is true about their distance? - Answer Star A is 3 times farther away than Star
B.
What is the name of the slightly cooler layer of the Sun just outside the photosphere?
- Answer Chromosphere
How does a star move on the H-R diagram during the period of time it is converting
hydrogen to helium in its core? - Answer It remains nearly fixed at a certain point on
the main sequence and does not move on the H-R diagram.
If the entire mass of Earth were concentrated in a region the size of a marble, the
resulting object would be... - Answer A black hole
Which is the smallest object? - Answer A neutron star
A galaxy has an H-alpha emission line observed at a wavelength 10 percent larger
than the rest wavelength of H-alpha. What is the redshift of the galaxy? - Answer 0.1
Which is the most luminous? - Answer Quasar
Which contains the most stars? - Answer A spiral galaxy
Galaxy A appears twice the angular size of Galaxy B. Assuming the two galaxies
have the same physical size in kiloparsecs, which of the following is true? - Answer
Galaxy B is 2 times farther away than Galaxy A
What fundamental particles make up a Helium-3 atom? - Answer 5 up quarks, 4
down quarks, 2 electrons
Which statement is FALSE?
A. Planetary nebulae can have layers because of pulsating stars
B. Planetary nebulae usually last tens of thousands of years
C. A planetary nebula will be part of the end state of the Sun
D. Planetary nebulae usually have black holes at their centers
E. Planetary nebulae are a few light years in size - Answer D. Planetary nebulae
usually have black holes at their centers
Which statement is true? - Answer Stars form in molecular clouds, where
temperature are about 10 Kelvin.
How tiny a spot is the Hubble Deep Field? - Answer The size of President
Roosevelt's eye on a dime held at arm's length
Correct!!
A high luminosity star - Answer Emits more light than a low-luminosity star
If a red giant appears the same brightness as a red main sequence star, which one
is farther away? - Answer The red giant
The heaviest nuclei of all are formed... - Answer During a supernova explosion
Hydrogen-2 + proton = ____ + energy: - Answer Helium-3
Which of the following has the smallest radius? - Answer Neutron star
Why does the main sequence part of a star's life end? - Answer The hydrogen in the
core is exhausted.
Which of the following will have the shortest lifetime on the main sequence? -
Answer Main sequence star with surface temperature 20000 K
Many of the brightest 100 stars viewed from Earth are not on the main sequence
(even though most stars are) because... - Answer The most luminous stars are
giants and supergiants that have already finished their main sequence lifetimes
A 2-solar-mass main sequence star is the same distance as a 0.2-solar-mass main
sequence star. Which star appears brighter? - Answer The 2 solar mass main
sequence star appears brighter
The temperature of the photosphere of the Sun is closest to... - Answer 6000 Kelvin
An estimate of the number of communicating/technological civilizations that we
expect in our Galaxy would be a larger number if... - Answer The average number of
planets that could support life for each star were larger
If the sun had twice its mass, then which of these planets would be in its habitable
zone? - Answer Jupiter
how do astronomers measure the temperature of stars? - Answer By looking at
which absorption lines are present in the star's spectrum.
The largest fraction of nearby stars (e.g. within 100 light years) are... - Answer Red
main sequence stars
The parallax angle of a nearby star is measured to be 0.02 arcseconds. What is the
distance to the star? - Answer 50 parsecs
, Which of the following is the sequence of events for a 40-solar mass star (one of the
most-massive stars)? - Answer Stellar nursery, protostar, blue star on main
sequence, Type 2 supernova, black hole
Star A is 9 times as luminous as Star B. The two stars appear the same brightness.
What is true about their distance? - Answer Star A is 3 times farther away than Star
B.
What is the name of the slightly cooler layer of the Sun just outside the photosphere?
- Answer Chromosphere
How does a star move on the H-R diagram during the period of time it is converting
hydrogen to helium in its core? - Answer It remains nearly fixed at a certain point on
the main sequence and does not move on the H-R diagram.
If the entire mass of Earth were concentrated in a region the size of a marble, the
resulting object would be... - Answer A black hole
Which is the smallest object? - Answer A neutron star
A galaxy has an H-alpha emission line observed at a wavelength 10 percent larger
than the rest wavelength of H-alpha. What is the redshift of the galaxy? - Answer 0.1
Which is the most luminous? - Answer Quasar
Which contains the most stars? - Answer A spiral galaxy
Galaxy A appears twice the angular size of Galaxy B. Assuming the two galaxies
have the same physical size in kiloparsecs, which of the following is true? - Answer
Galaxy B is 2 times farther away than Galaxy A
What fundamental particles make up a Helium-3 atom? - Answer 5 up quarks, 4
down quarks, 2 electrons
Which statement is FALSE?
A. Planetary nebulae can have layers because of pulsating stars
B. Planetary nebulae usually last tens of thousands of years
C. A planetary nebula will be part of the end state of the Sun
D. Planetary nebulae usually have black holes at their centers
E. Planetary nebulae are a few light years in size - Answer D. Planetary nebulae
usually have black holes at their centers
Which statement is true? - Answer Stars form in molecular clouds, where
temperature are about 10 Kelvin.
How tiny a spot is the Hubble Deep Field? - Answer The size of President
Roosevelt's eye on a dime held at arm's length
