Multiple Choice
A Cepheid variable star with a pulsation period of a few days is seen in the spiral arm of a galaxy.Its apparent brightness is measured as 10⁴ times fainter than an equivalent star 1000 ly away from the Sun in the Milky Way Galaxy.Assuming no light absorption between galaxies,what is the distance to the far Cepheid and hence to the galaxy?
A) 10⁷ ly (10⁴ times farther away)
B) 10,000 ly (10 times farther away)
C) 10 ly (100 times closer)
D) 100,000 ly (100 times farther away)
Correct Answer:

Verified
Correct Answer:
Verified
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