In: Physics
a. Variable stars can be used to estimate the distance to astronomical objects which contain them. If there is a significant amount of dust in the line of sight, these stars will appear fainter in the optical than what really are. What would happen to the distance estimate if one does not correct for the presence of dust extinction? Explain qualitatively.
b. Do weak encounters significantly affect the trajectory of a star in a galaxy?
c. Two astronomical sources have exactly the same
luminosity, but one is located in the nearby Universe and the other
one at z = 1. What would be approximately the ratio between their
surface brightenesses?
d. Ennumerate two main star formation tracers in
galaxies.
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