A Cepheid star is a type of variable star, which means its brightness is not constant. The relationship between the brightness of a Cepheid star and its period, or length of its pulse, is given by M = - 2.78 (log P) - 1.35, where M is the absolute magnitude, or brightness, of the star, and P is the number of days required for the star to complete one cycle. What is the absolute magnitude of a star that has a period of 45 days? Use a calculator. Round your answer to the nearest hundredth.

Question

Marc Moss

4 August, 13:27

+3

Answers (1)

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Jean Beltran · Answer 1

M = - 2.78log (P) - 1.35

M = - 2.78log (45) - 1.35

M = - 2.78 (1.65) - 1.35

M = - 4.587 - 1.35

M = 5.937

M = - 5.94