Answer Options:
white dwarf
neutron star
black hole
singularity
Answer: black hole
Question: Why do HII regions appear red?
Answer Options:
HII regions consist of neutralized hydrogen gas in a molecular state. Red photons are formed when the hydrogen gas is cooled to the temperatures found in interstellar space.
HII regions are composed of singly ionized hydrogen gas. This gas ionizes electrons and forms the hydrogen absorption lines. Since this is so intense, the observer only sees it in red.
HII regions are composed of completely ionized hydrogen. When the hydrogen captures an electron, HII is emitted. The red Balmer hydrogen line is the strongest wavelength emitted.
Light from HII regions suffer more indirect reddening than light from other sources. A blue HII region passes through clouds of dust that have a bluer and redder light passed to us, making the regions appear red.
Answer: HII regions are composed of completely ionized hydrogen. When the hydrogen captures an electron, HII is emitted. The red Balmer hydrogen line is the strongest wavelength emitted.
Question: The first star system that was a candidate for a black hole was ….
Answer Options:
Tycho’s star
Cygnus X-1
LIGO
V404 Cyg
LMC X-3
Answer: Cygnus X-1
Question: The astronomer who mapped the orbits of stars near the Milky Way Galaxy’s supermassive black hole was _____.
Answer Options:
Caroline Herschel
Walter Baade
Harlow Shapley
Andrea Ghez
Answer: Andrea Ghez
Question: Which of the following [more than one] could potentially produce gravitational waves strong enough to detect here on Earth?
Answer Options:
The merger of two neutron stars.
The orbit of a star about the supermassive black hole at the center of the Milky Way Galaxy.
The acceleration of a Chevrolet sedan’s car.
Answer: The merger of two neutron stars.
The orbit of a star about the supermassive black hole at the center of the Milky Way Galaxy.
Question: What do astronomers consider ‘heavy elements’?
Answer Options:
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: An astronomer finds a star with surface temperature of 3000 K with a high luminosity. What kind of star is this?
Answer Options:
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: Most of the energy of a supernova is released in the form of…
Answer Options:
visible light.
fusion reactions.
the physical destruction of the star.
neutrinos.
Answer: neutrinos.
Question: ____ stars are held up by neutron degeneracy.
Answer Options:
Main sequence
Neutron
Type Ib
White dwarf
Answer: Neutron
Question: What type of star is the Sun?
Answer Options:
Pop II
Pop I
Dark Matter Star
Pop III
Answer: Pop I
Question: Which of the following main sequence stars is most likely to end in a type II supernova?
Answer Options:
K3V
G2V
M2V
O5V
Answer: O5V