Term
The light we see from the Sun comes from which layer?
A) troposphere
B) ionosphere
C) corona
D) chromosphere
E) photosphere |
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Why couldn't you stand on the Sun's surface?
A) You could stand on it, if a sufficiently protective spacesuit could be designed.
B) The Sun's surface is too highly magnetized for anything to survive there.
C) The Sun doesn't have a solid surface.
D) You could stand on the surface.
E) The Sun has no surface at all...the photosphere is an illusion. |
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Term
What is the net result of the proton-proton chain?
A) 3 helium 4 fuse to make C 12
B) 2 hydrogens and 1 helium are fused into 1 carbon + energy
C) 2 heliums are fused into 1 carbon, 1 neutrino + energy
D) 4 hydrogens are fused into 1 helium, 2 neutrinos + energy
E) 2 protons make deuterium + a neutrino |
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Term
The critical temperature to initiate fusion via the proton-proton cycle in the cores of stars is:
A) 5,800 K
B) 3,000 K
C) 10 million K
D) 2,300,000 K
E) 100 million K |
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The pattern of rising hot gas cells all over the photosphere is called:
A) granulation.
B) filaments.
C) sunspots.
D) convective projections.
E) prominences. |
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Term
When the chromosphere can be seen during a solar eclipse, it appears:
A) violet.
B) invisible.
C) red.
D) blue.
E) yellow. |
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Term
The ________ Minimum was a period of solar inactivity between 1645 and 1715.
A) Maunder
B) Galileo
C) Spitzer
D) Schwarzschild
E) Hubble |
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Definition
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Term
The absolute magnitude of a star is its brightness as seen from a distance of:
A) one million kilometers.
B) one light year.
C) one astronomical unit.
D) ten parsecs.
E) 10 light years. |
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Term
Perhaps the greatest of the Greek astronomers, ________ compiled the first catalog of stars, accurately measured their positions, and defined the basic system of stellar brightnesses.
A) Aristotle
B) Hipparchus
C) Aristarchus
D) Ptolemy
E) Erastothenes |
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Term
Which statement about stellar motion is incorrect?
A) The radial velocity is measured by the Doppler shift.
B) In general, the closer a star is, the more its proper motion.
C) The transverse velocity is measured by the proper motion and the distance.
D) Like parallax, proper motion is measured over intervals of exactly six months.
E) The Pythagorean theorem relates space, transverse, and radial velocities. |
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Definition
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Term
Hipparcos' observations have given us good data on stars out to about:
A) 1000 light years.
B) 100 light years.
C) 200 parsecs.
D) 200 light years.
E) 1000 parsecs. |
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Definition
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Term
What is the absolute magnitude of our Sun?
A) -1.4
B) +4.8
C) -4.6
D) -26.7
E) +9.4 |
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Term
What physical property of a star does the spectral type measure?
A) mass
B) density
C) luminosity
D) composition
E) temperature |
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Term
Stellar masses are determined directly by observation of the orbits and periods of:
A) only eclipsing binary systems.
B) only spectroscopic binary systems.
C) only visual binary systems.
D) any binary system.
E) only astrometric binary systems. |
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Term
Interstellar gas is composed mainly of:
A) hydrogen.
B) methane.
C) carbon dioxide.
D) helium.
E) ammonia. |
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Term
Why are dark dust clouds largely misnamed?
A) All of the answer choices are correct.
B) They contain much more gas than dust.
C) The appearance of a cloud is an illusion; dust is scattered very evenly throughout the Galaxy.
D) They give off huge amounts of X and gamma rays due to their polarization.
E) Dust clouds are not dark but emit significant amounts of visible light. They just look dark compared to the bright stars. |
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Term
Interstellar absorption lines are narrow primarily because:
A) the matter is at a low temperature, atoms are almost still.
B) All of the answer choices are correct.
C) molecules always produce narrow absorption lines.
D) there is very little interstellar matter.
E) most of the matter is ionized and atoms moving fast produce sharp lines. |
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Term
What effect does dust have on visible light passing through it?
A) It dims and reddens it.
B) It completely blocks all visible light from passing through.
C) It ionizes the light and creates emission lines.
D) It makes the light coming from stars appear to twinkle
E) All light is turned bluish in color. |
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Which two ingredients are needed to make an emission nebula?
A) methane and ammonia
B) cool M giant stars and interstellar gas
C) hot O-B stars and interstellar gas
D) cool red stars and interstellar dust
E) interstellar gas and dust |
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Term
Which statement about the dark nebulae is false?
A) Iron atoms probably help in the polarizing effect of the magnetic fields.
B) They comprise the majority of the mass of the whole Galaxy.
C) Their components are much like comet dust from the Oort Cloud.
D) Carbon and silicates are the chief absorbing and scattering agents.
E) They block the vast majority of our Galaxy from us in visual wavelengths. |
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Term
An emission nebula appears primarily ___________ in color, due to ionized hydrogen.
A) blue
B) yellow
C) red
D) purple |
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