A) 10,000 years.
B) 25,000 years.
C) 100,000 years.
D) a few million years.
E) 100 million years.
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Gas is almost all hydrogen and...View Answer
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A star is only stable when the...View Answer
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A) Mostly found above and below the galactic plane
B) Old age and millions of members
C) A few hundred, mainly main sequence stars
D) All stars are much more massive than our Sun.
E) All stars are about the same age and luminosity.
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A) it must always end up as a black hole.
B) it generates more heat and its core eventually collapses very suddenly.
C) it cannot fuse elements heavier than carbon.
D) gravity is weakened by its high luminosity.
E) it is most often found as part of a binary system.
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A) it completely runs out of hydrogen.
B) it expels a planetary nebula to cool off and release radiation.
C) it explodes as a violent nova.
D) it builds up a core of inert helium.
E) it loses all its neutrinos, so fusion must cease.
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A) about the same mass and density.
B) about the same mass and a million times higher density.
C) a larger mass and a 100 times lower density.
D) a smaller mass and half the density.
E) a smaller mass and twice the density.
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A) One star forms at its center and blows the rest of the matter back into space.
B) The cloud fragments into smaller clouds and forms many stars at one time.
C) One star forms and the rest of the matter goes into making planets, moons, and other objects of a solar system.
D) The cloud is disrupted by rotation so that it reduces its mass down to that of a typical star.
E) A supernova blows the cloud up and dissipates the majority of the gas.
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The interstellar dust grains a...View Answer
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The core of the Sun had an initial compo...View Answer
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A) The lowest mass main sequence stars
B) The end result of massive star evolution
C) Objects that are not quite massive enough to be stars
D) Pulsars that have slowed down and stopped spinning
E) Cooled off white dwarfs that no longer glow visibly
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The ignition of nucl...View Answer
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fusion (of hydrogen ...View Answer
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The cloud fragments ...View Answer
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A) No stars as hot as our Sun
B) Old age and hundreds of thousands to millions of member stars
C) No main sequence stars left, with billions of member stars
D) A few hundred stars, most still on the main sequence
E) Hundreds of light years across, with bright OB stars dominant
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In this nebula, there is a single energe...View Answer
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A) within the last few million years.
B) about 10 million years ago.
C) hundreds of millions of years ago.
D) billions of years ago.
E) at the beginning of the universe.
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