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Question
On a night when a human eye can see a fourth magnitude star, a 60mm telescope, with 100 the surface area as our pupil, would be able to just barely detectA) seventh magnitude Titan, Saturn's largest moon.
B) eighth magnitude Uranus.
C) ninth magnitude Barnard's Star.
D) eleventh magnitude Tethys, Saturn's second largest moon.
E) thirteenth magnitude Pluto.
Answer
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