To determine the sum of the masses of a visual binary star system, what needs to be measured?
A) temperatures and periods of the stars
B) distance from Earth and the semimajor axis of the orbit of one star relative to the other
C) periods and the semimajor axes of the stars
D) temperatures and distances from Earth of the stars

Question

Quizplus · Accepted Answer

The sum of the masses of a visual binary star system can be determined by measuring the periods and the semimajor axes of the stars' orbits. This is based on Kepler's third law of planetary motion, which relates these two quantities to the mass of the system.

To Determine the Sum of the Masses of a Visual