Applications to Astronomy: A star has absolute luminosity equal to that of the sun but is 10 pc away from the Earth. By what factor will it appear dimmer than the sun? The earth is 1.5 × 108 km from the sun, and 1 parsec is equal to 3.09 × 1016 m.
A. 2 × 10-9
B. 2 × 10-11
C. 2 × 10-13
D. 2 × 10-15
Answer: C
Physics & Space Science
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