What fundamental property does Kepler’s law of binaries primarily allow astronomers to calculate for a stellar pair?

Answer

The total mass of the stellar pair (M1 + M2).

The application of Kepler's work to binary systems, using the modified Third Law, allows for the direct calculation of the combined mass (M1 + M2) by measuring the period and separation.

What fundamental property does Kepler’s law of binaries primarily allow astronomers to calculate for a stellar pair?
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