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12 Cards in this Set
- Front
- Back
Which of these galaxies is most likely to be oldest? |
A galaxy observed at a distance of 5 billion light-years |
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Which set of star-position measurments most likely shows the largest parallax shift for nearby stars? |
Measurments made by 6 moths apart |
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If earths orbital radius doubled in size, |
the parallax shifts of nearby stars would double in size |
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If all the stars on the main sequence of a star cluster are typically one-hundredth as bright as their main-sequence counterparts in the Hydas Cluster, then that clusters distance is |
10 times the hydas distance |
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Which kind of object is the best standard candle for measuring distances to extremely distant galaxies |
A white dwarf supernova |
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If you observe two cephid variable stars to have the same period and one is brighter than the pther |
the brighter one is closer |
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If you observe two cephid variable stars to have different periods and the birghter one has a longer period |
there is not enough info to determine which star is closer |
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When ultraviolet light from hot stars in very distant galaxies finally reaches us, it arrives at earth in the form of |
visible light |
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Why do virtually all the galaxies in the universe appear to be moving away from our own? |
Obvservers in all galaxies see a similar phenomenon due to the universes expansions |
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If you observe the redshifts of galaxies at a given distance to be twice as large as they are now, the value you would determine for hubbles constant would be |
twice its current value |
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What would you estimate for the universes age if hubbles constant were 11 kil. per sec per million light-years? |
28 billion years |
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When we observe a distant galaxy whose photons have treaveled gfor 10 billion years before reaching earth, we are seeing that galaxy as it was when the universe was about |
4 billion years old |