•Question 13 (1 point) One fundamental requirement for an object to be a good tracer (i.e. marker) of the galaxy's spiral arms is that it be
a.moving with small radial velocity (relative
to earth).
b.moving with large radial velocity (relative to earth). c. a short lived and therefore young object. d. a very long lived and therefore probably old object.
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•Question 14 (2 points, extra credit). The answer is tidal
forces which you can get easily if
you read the story
“Neutron Star.”
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