Question: A star of spectral class B2 undergoes core collapse and explodes in a supernova. What type of supernova is this?

Answer Choices:
Type Ia
Type Ib
Type II
Main sequence

Answer: Type II

 

Question: The maximum mass for a neutron star is…

Answer Choices:
not known exactly but is somewhere about 3 solar-masses.
somewhere about 5 solar-masses.
unlimited. There is no maximum limit.
1.4 solar masses.

Answer: not known exactly but is somewhere about 3 solar-masses.

 

Question: Why do older stars have lower heavy-element abundances?

Answer Choices:
The relative abundances of heavy elements was much higher in the past, but today young stars use up lots of hydrogen in their masses.
The interstellar medium from which they formed was not enriched with heavy elements formed in stellar interiors.
Only stars with low heavy-element abundances are easily observed. This is a survivorship bias.
Old stars are lower mass and are not able to fuse elements beyond carbon.

Answer: The interstellar medium from which they formed was not enriched with heavy elements formed in stellar interiors.

 

Question: What happens after the electron degenerate iron core of a high mass star collapses into a neutron degenerate core?

Answer Choices:
Type Ia supernova
Type Ib supernova
Neutrons are released and not much else
Type II supernova

Answer: Type II supernova

 

Question: Most of the energy of a supernova is released in the form of…

Answer Choices:
visible light.
fusion reactions.
the physical destruction of the star.
neutrinos.

Answer: neutrinos.

 

Question: Which of the following main sequence stars is most likely to end in a type II supernova?

Answer Choices:
K3V
G2V
M2V
O5V

Answer: O5V

 

Question: Which of the following correctly uses the term “light year”?

Answer Options:
A light year is how long it takes light to travel one year.
A light year is how long it takes for the Sun to burn out.
A light year is the time a star lives but with no distinct planets like exoplanets.
A light year is the distance light travels in one year.

Correct Answer:
A light year is the distance light travels in one year.

Answer Choices:
A light year is how long it takes light to travel one year.
A light year is how long it takes for the Sun to burn out.
A light year is the time a star lives but with no distinct planets like exoplanets.
A light year is the distance light travels in one year.

Answer: A light year is the distance light travels in one year.

 

Question: If a star orbits the MWG’s halo above the galactic disk in the halo, what type of star is it?

Answer Choices:
That’s no star!
Pop I
Pop II
Dark Matter Star

Answer: Pop II

 

Question: Which of the following main sequence stars would be the most massive?

Answer Choices:
M2
F6
K2
O9

Answer: O9

 

Question: What is a pulsar?

Answer Choices:
a star that expands and contracts like a Cepheid.
a binary star system with a white dwarf star.
a rapidly rotating neutron star.
a star burning iron in its core.

Answer: a rapidly rotating neutron star.

 

Question: A star is no longer considered a main sequence star when…

Answer Choices:
another star comes along
it starts fusing helium in its core
a younger star comes along
a more massive star comes along
it stops fusing hydrogen in its core

Answer: it stops fusing hydrogen in its core

 

Question: Astronomers estimate that the ISM makes up about ____ of the total mass of the Milky Way Galaxy.

Answer Options:
42%
15%
9%
25%

Correct Answer:
15%

Answer Choices:
42%
15%
9%
25%

Answer: 15%

 

Question: SN 1987A is an example of a…

Answer Choices:
Type Ia supernova.
planetary nebula.
white dwarf.
Type II supernova.

Answer: Type II supernova.

 

Question: How do we know dark matter exists in the halo?

Answer Choices:
Measurements of orbital speeds at different distances from the MWG’s center show rotation curves that do not obey Keplerian physics. This indicates a large amount of unseen mass.
The formation of stars and low luminosity stars from dark matter points to the existence of vast amounts of unseen matter.
The gravitational interaction of stars near the center of the MWG point to the existence of large amounts of unseen matter.
Measurements of dark matter imply that its orbital velocity falls off very far from the MWG’s center. This can best be explained as a large amount of dark matter existing in the halo.

Answer: Measurements of orbital speeds at different distances from the MWG’s center show rotation curves that do not obey Keplerian physics. This indicates a large amount of unseen mass.

 

Question: Elements up to iron are fused inside of high mass stars, but how are elements beyond iron created?

Answer Choices:
Nuclear reactions in the cooling core of a white dwarf can fuse with the iron core of a massive star in a binary star system to form elements heavier than iron.
Nuclear reactions in the brief period of a supernova explosion can form elements beyond iron.
Events heavier than iron are fused inside the cores of the most massive stars in the universe.
Iron fuses into heavier elements when the hydrogen burning shell is exhausted.

Answer: Nuclear reactions in the brief period of a supernova explosion can form elements beyond iron.