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12 votes
12 votes
Star A is at 2pc and has an apparent magnitude of 4. Star C is at 50 pc and has an apparent magnitude of 2. Which of the most intrinsically bright star?

A.
Star A because it is closest to the moon
B.
Star B because the apparent magnitude is a larger number than A and C
C.
Star C because it’s absolute magnitude will have the smallest value campsites to A and B
D.
Star A and C have the same intrinsic brightness because they appear equally bright yy

User Ahll
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1 Answer

23 votes
23 votes

The list of choices is a mess. None of them is correct.

Star C ... even though it's 25 times as far from our eyes as Star A is ... still appears 2 magnitudes brighter !

Star C must be a wicked hot-ball, intrinsically waaaay brighter than Star A . A wild and wooly blowtorch compared to star A. Something like 4,200 times as bright as Star A .

User Kroshka Kartoshka
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2.6k points