Question: The astronomer who mapped the orbits of stars near the Milky Way Galaxy’s supermassive black hole was _____.

Answer Choices:
Caroline Herschel
Walter Baade
Harlow Shapley
Andrea Ghez

Answer: Andrea Ghez

 

Question: When did the Milky Way Galaxy begin its formation?

Answer Choices:
about 13.8 billion years ago
about 10 million years ago
about 100,000 years ago
about 4.5 billion years ago

Answer: about 13.8 billion years ago

 

Question: Which of the following is closest in size (radius) to a neutron star?

Answer Choices:
Earth
the Sun
a small city
a beach ball

Answer: a small city

 

Question: What proof do we have of ultra-hot ISM temperatures?

Answer Options:
Astronomers have recorded X-ray spectra from cold molecules, which are only forged at temperatures of millions of degrees.
Astronomers have seen visible HII regions and recorded radio wave absorption in hydrogen gas, which only occur at billions of degrees.
Astronomers have recorded radio wave emissions from ISM gas and have observed spectra of hydrogen atoms with dopplerization.
Astronomers have recorded X-ray emissions from ISM gas and observed the spectra of oxygen atoms with few levels of ionization.

Correct Answer:
Astronomers have recorded X-ray emissions from ISM gas and observed the spectra of oxygen atoms with few levels of ionization.

Answer Choices:
Astronomers have recorded X-ray spectra from cold molecules, which are only forged at temperatures of millions of degrees.
Astronomers have seen visible HII regions and recorded radio wave absorption in hydrogen gas, which only occur at billions of degrees.
Astronomers have recorded radio wave emissions from ISM gas and have observed spectra of hydrogen atoms with dopplerization.
Astronomers have recorded X-ray emissions from ISM gas and observed the spectra of oxygen atoms with few levels of ionization.

Answer: Astronomers have recorded X-ray emissions from ISM gas and observed the spectra of oxygen atoms with few levels of ionization.

 

Question: An astronomer finds a star with surface temperature of 3000 K with a high luminosity. What kind of star is this?

Answer Choices:
Since Mars is so cool and with little energy even over a large square meter total, the only way that an M star can have a high luminosity is if it is very large (i.e., has a lot of square meters of surface area). This star is either a giant or a supergiant.
Since the star is an M type star it is cool. The luminosity is high because the star is probably close to Earth reflecting it appear much more luminous. The star is a red dwarf.
The star is a G2 main sequence star.
This star is probably a white dwarf with a cloud surrounding it that lowers the observed temperature and makes the star appear to have a high luminosity.

Answer: Since Mars is so cool and with little energy even over a large square meter total, the only way that an M star can have a high luminosity is if it is very large (i.e., has a lot of square meters of surface area). This star is either a giant or a supergiant.

 

Question: The most massive region of the Milky Way Galaxy is _____.

Answer Choices:
the galaxy’s bulge
the dark matter halo
the galaxy’s disk
the supermassive black hole

Answer: the dark matter halo

 

Question: One AU is…

Answer Options:
A short for one astronomical unit.
All of these are correct.
The average distance from Earth to the Sun.

Correct Answer:
A short for one astronomical unit.

Answer Choices:
A short for one astronomical unit.
All of these are correct.
The average distance from Earth to the Sun.

Answer: A short for one astronomical unit.

 

Question: Suppose a binary star system consists of a white dwarf star that is gaining mass because of accretion from its companion star. When the white dwarf reaches a mass of 1.4 solar-masses what happens?

Answer Choices:
The white dwarf swells up and begins to fuse elements beyond carbon in its core.
A white dwarf can never gain enough mass to reach the limit because a strong stellar wind prevents the accreted from reaching it in the first place.
The white dwarf immediately collapses into a black hole, disappearing from view.
The white dwarf undergoes a catastrophic collapse, leading to a type of supernova that is somewhat different from that which occurs in a single massive star but is comparable in energy.

Answer: The white dwarf undergoes a catastrophic collapse, leading to a type of supernova that is somewhat different from that which occurs in a single massive star but is comparable in energy.

 

Question: Which of the following is the best candidate to explain cosmic rays?

Answer Options:
particles from the Sun’s solar wind
galactic or extra-galactic supernova explosions
collisions within hot interstellar clouds

Correct Answer:
galactic or extra-galactic supernova explosions

Answer Choices:
particles from the Sun’s solar wind
galactic or extra-galactic supernova explosions
collisions within hot interstellar clouds

Answer: galactic or extra-galactic supernova explosions

 

Question: What explains the metallicity difference between population I and population II stars?

Answer Choices:
Population I stars are of spectral type like our Sun or possibly cooler. Population II stars are of spectral type that is typically less solar-like. Nuclear reactions in the hotter, more massive stars, causing the metallicity difference between the two populations.
Population II stars formed in regions of the MWG where heavy elements were plentiful. Population I stars formed in regions of the MWG where heavier elements were scarce. As a result, Population I stars are older than population II stars and have therefore had a much longer time to be enriched by heavy elements.
Population I stars formed when the abundance of elements heavier than hydrogen and helium was low. Population I stars formed later. All stars but the dying members of the first generations of stars had enriched the interstellar medium with elements heavier than hydrogen and helium.

Answer: Population I stars formed when the abundance of elements heavier than hydrogen and helium was low. Population I stars formed later. All stars but the dying members of the first generations of stars had enriched the interstellar medium with elements heavier than hydrogen and helium.

 

Question: Which of the following main sequence stars is most likely to undergo a helium flash later in its evolution?

Answer Choices:
O1
G9
K6
B3

Answer: G9

 

Question: Which of the following would be most likely to show a main sequence turnoff point around F9?

Answer Choices:
OB Stellar Association
Spheroid Cluster
Young Open Cluster
Globular Cluster

Answer: Globular Cluster

 

Question: Which of the following stages is best explained as the outer layers of a star blown into space and illuminated by a hot central star?

Answer Choices:
red supergiant
helium flash
planetary nebula
red giant

Answer: planetary nebula

 

Question: If a cluster shows a main sequence turnoff point at G2, what is the approximate age of the cluster?

Answer Choices:
200 million years old
10 million years old
4-5 billion years old
10 billion years old

Answer: 4-5 billion years old

 

Question: What do astronomers consider ‘heavy elements’?

Answer Choices:
elements that are heavier than iron
all elements besides hydrogen and helium
elements that are heavier than uranium
elements that are heavier than carbon

Answer: all elements besides hydrogen and helium

 

Question: What core temperature is required for helium fusion to occur?

Answer Choices:
100 million K
1 million K
15 million K
100 billion K

Answer: 100 million K

 

Question: Suppose a single star has spectral features indicating it has a high surface temperature that emits mostly blue light, but when observed, the star appears red. What is an explanation for this?

Answer Options:
The star is more heavily associated with a hot HII region. The hydrogen in its HII region will glow blue and add up all the blue light from the star.
This indicates that the star is moving away rapidly so that the blue light is redshifted by the Doppler effect.
Light from the hot star passes through clouds containing interstellar dust. The dust scatters blue light far more and allows red light to pass through. The effect is that the star appears red even though it is emitting mostly blue light.

Correct Answer:
Light from the hot star passes through clouds containing interstellar dust. The dust scatters blue light far more and allows red light to pass through. The effect is that the star appears red even though it is emitting mostly blue light.

Answer Choices:
The star is more heavily associated with a hot HII region. The hydrogen in its HII region will glow blue and add up all the blue light from the star.
This indicates that the star is moving away rapidly so that the blue light is redshifted by the Doppler effect.
Light from the hot star passes through clouds containing interstellar dust. The dust scatters blue light far more and allows red light to pass through. The effect is that the star appears red even though it is emitting mostly blue light.

Answer: Light from the hot star passes through clouds containing interstellar dust. The dust scatters blue light far more and allows red light to pass through. The effect is that the star appears red even though it is emitting mostly blue light.

 

Question: What do we call the spherical region of matter that surrounds the visible portion of the Milky Way Galaxy?

Answer Choices:
the galaxy’s cluster
the galaxy’s disk
the galaxy’s bulge
the galaxy’s halo

Answer: the galaxy’s halo

 

Question: True or False? Most of the ISM is composed of ionized hydrogen (HII).

Answer Options:
True
False

Correct Answer:
True

Answer Choices:
True
False

Answer: True

 

Question: Trick question: is there milk in the Milky Way Galaxy?

Answer Choices:
No.
Yes.

Answer: No.

 

Question: ____ stars are held up by electron degeneracy.

Answer: White dwarf

 

Question: If a star has a parallax of 0.01 seconds of arc, what is the star’s distance?

Answer Options:
1 pc
10 pc
0.01 pc
0.1 pc
100 pc

Correct Answer:
100 pc

Answer Choices:
1 pc
10 pc
0.01 pc
0.1 pc
100 pc

Answer: 100 pc