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.   visible
B.   gamma
C.   infrared
D.   X-ray
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.   460,000
B.   13.7 billion
C.   4.6 billion
D.   13.7 million
Question #3
Radiation with a wavelength of 21 cm is emitted as a result of
A.   high energy vibrations.
B.   low energy vibrations.
C.   the transitioning from orbital to orbital of hydrogen's electron.
D.   the electron of hydrogen flipping upside down.
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.   mostly gas and a bit of dust.
B.   the emptiness of space.
C.   mostly dust and a bit of gas.
D.   medium amounts of interstellars.
Question #6
The red light observed in emission nebulae results from photons of light emitted from
A.   carbon monoxide.
B.   hydrogen.
C.   helium.
D.   oxygen.
Question #7
The overall reduction in intensity of observed starlight results from
A.   absorption spectra.
B.   absorptive gases.
C.   interstellar extinction.
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.   H2O (water molecules - or dihydrogen monoxide, if you will)
B.   CH (carbyne molecules)
C.   O2 (oxygen molecules)
D.   CO (carbon monoxide)
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.   5800 K
B.   333,000 K
C.   5 million K
D.   10 million K
Question #11
Which of the following is not a possible trigger for molecular cloud collapse?
A.   supernovae
B.   solar flares
C.   starlight
D.   collision of ISM clouds
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.   thermonuclear fusion process increasing its rate of helium production.
B.   presence of high energy particles.
C.   increased pressure from the overlying layers of mass above the cores.
D.   spin flip of hydrogen.
Question #13
"A star is born" when
A.   thermonuclear fusion begins in its core.
B.   a Bok globule becomes big enough to collapse.
C.   hydrostatic equilibrium is reached.
D.   Lady Gaga and Bradley Cooper sing "Shallow" together at the Oscars.
Question #14
When the core of a protostar is sufficiently hot, nuclear fusion of begins.
A.   heliogen
B.   helium
C.   hydrogen
D.   atoms
Question #15
What force causes the atoms and molecules of the nebula to start forming more dense regions?
A.   the force of nature
B.   the force of gravity
C.   electromagnetic force
D.   F = ma
Question #16
The evolutionary path of a protostar on the HR Diagram is called its
A.   Hiromasa track.
B.   Hayashi track.
C.   Subaru path.
D.   Barnard displacement.

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