Astronomy 120 - Stars and Galaxies » Fall 2022 » Unit 8 Quiz
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Question #1
In order to see through a dark nebula and observe the stars behind it, we must make observations within the range of EM radiation.
A.
gamma
B.
visible
C.
X-ray
D.
infrared
Question #2
The hydrogen and helium atoms found in the ISM have existed since the Big Bang, which occurred almost how many years ago?
A.
4.6 billion
B.
13.7 million
C.
460,000
D.
13.7 billion
Question #3
Radiation with a wavelength of 21 cm is emitted as a result of
A.
low energy vibrations.
B.
high energy vibrations.
C.
the electron of hydrogen flipping upside down.
D.
the transitioning from orbital to orbital of hydrogen's electron.
Question #4
There is virtually no interstellar medium in the galaxy.
A.
True
B.
False
Question #5
The interstellar medium is made up of
A.
medium amounts of interstellars.
B.
mostly dust and a bit of gas.
C.
the emptiness of space.
D.
mostly gas and a bit of dust.
Question #6
The red light observed in emission nebulae results from photons of light emitted from
A.
oxygen.
B.
helium.
C.
carbon monoxide.
D.
hydrogen.
Question #7
The overall reduction in intensity of observed starlight results from
A.
interstellar extinction.
B.
absorption spectra.
C.
absorptive gases.
D.
reducing nebulae.
Question #8
Molecular nebulae are virtually invisible. The hydrogen atoms, joined together as H2, don't emit any light of any wavelength. But they are known to hang out with other molecules that do emit light at 1.3 mm and 2.6 mm. What are these other molecules?
A.
CH (carbyne molecules)
B.
O2 (oxygen molecules)
C.
CO (carbon monoxide)
D.
H2O (water molecules - or dihydrogen monoxide, if you will)
Question #9
If a protostar's core reaches a temperature of 6 million degrees, it will start fusing hydrogen into helium.
A.
True
B.
False
Question #10
The minimum temperature needed to ignite thermonuclear fusion in main sequence stars is
A.
333,000 K
B.
10 million K
C.
5 million K
D.
5800 K
Question #11
Which of the following is not a possible trigger for molecular cloud collapse?
A.
collision of ISM clouds
B.
supernovae
C.
solar flares
D.
starlight
Question #12
After the dense cores of the Bok globules gain sufficient mass, the very center of these cores begins to heat up. This is due to the
A.
spin flip of hydrogen.
B.
presence of high energy particles.
C.
thermonuclear fusion process increasing its rate of helium production.
D.
increased pressure from the overlying layers of mass above the cores.
Question #13
"A star is born" when
A.
hydrostatic equilibrium is reached.
B.
Lady Gaga and Bradley Cooper sing "Shallow" together at the Oscars.
C.
thermonuclear fusion begins in its core.
D.
a Bok globule becomes big enough to collapse.
Question #14
When the core of a protostar is sufficiently hot, nuclear fusion of begins.
A.
hydrogen
B.
atoms
C.
heliogen
D.
helium
Question #15
What force causes the atoms and molecules of the nebula to start forming more dense regions?
A.
electromagnetic force
B.
F = ma
C.
the force of nature
D.
the force of gravity
Question #16
The evolutionary path of a protostar on the HR Diagram is called its
A.
Hiromasa track.
B.
Barnard displacement.
C.
Hayashi track.
D.
Subaru path.
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