• Question
8 (1 point) If a sunspot has a temperature of 4200 K and the solar surface has a temperature of 5800 K, how many times brighter is the surface compared with the sunspot? (Hint: Use the Stefan-Boltzmann law.)
a. It isn't brighter
-- it is fainter!
•b.About 1.4 times brighter.
•c.About 3.6 times brighter.
•d.About 5.6 times brighter.
•Sunspot
brightness, use E = σT4
• (T1/T2)4 = (5800/4200)4 = 3.6 times brighter
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