Physics 110: Assignment 7

Due Wednesday, November 20.

  1. Stars A, B, and C are identical, but B is twice as far from Earth as A, and C is even farther away. How much less bright than A does B appear? If C appears only 1/900 as bright as A, how far away is it?

  2. A certain distant star gives light whose spectrum is identical to the Sun's. Viewed from Earth, it appears 0.0000 0000 0000 0001 times as bright as the Sun. How far away is it? Outline the logic which leads to your answer. (1 parsec is approximately 200,000 AU.)

  3. There are virtually no big main-sequence stars (bigger than, say, 3 solar masses) within about 100 Lyr of us. Why not?

Published by NDSU Department of Physics
Douglas A. Kurtze
E-mail: kurtze@plains.nodak.edu
Phone: (701) 231-7048
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