# Mass of stars

#### RileyAllen

Suppose that a binary-star system consists of two stars of equal mass. They are observed to be separated by 350 million {\rm km} and take 5.4 Earth years to orbit about a point midway between them.

I got 1.1x10^29 as my answer, but it is incorrect. Can anyone help me out?

#### LowlyPion

Homework Helper
Suppose that a binary-star system consists of two stars of equal mass. They are observed to be separated by 350 million {\rm km} and take 5.4 Earth years to orbit about a point midway between them.

I got 1.1x10^29 as my answer, but it is incorrect. Can anyone help me out?
You're looking for the orbital relationship for a two body rotating about themselves.

Do you have that equation in the book you are studying?

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