In a binary system, what two properties must be observed to determine the total mass using Newton's reformulation of Kepler's Third Law?

Answer

Average separation distance and orbital period

The sum of the masses ($M_1 + M_2$) in a binary system can be determined by observing the average separation distance ($D$) and the orbital period ($P$). The formula requires these two variables.

In a binary system, what two properties must be observed to determine the total mass using Newton's reformulation of Kepler's Third Law?
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