Multiple Choice
Spiral density wave theory and self-sustaining star formation are ways to explain why ____.
A) stars orbit the galaxy with different periods at different distances from the center
B) sun-like stars are evenly distributed through the disk of the galaxy
C) dark matter affects the orbit of stars outside the visible disk of the galaxy
D) molecular clouds are compressed forming young stars along spiral arms
E) the central bulge of the galaxy has a "bar" shape
Correct Answer:

Verified
Correct Answer:
Verified
Q4: The best explanation for the activity at
Q5: _ are crucial in determining the distance
Q6: Why is it surprising that spiral arms
Q7: Stars that formed in the very early
Q8: Spiral arms are obvious-easily-seen features-because they contain
Q10: The center of the galaxy has been
Q11: How have astronomers determined the mass of
Q12: The first stars formed in the Universe
Q13: An astronomer named _ used globular clusters
Q14: O and B stars are important spiral