How do two unequal-mass stars in a binary star system move around each other, in general?
A) The stars move in a single circular orbit around the same center and always on opposite sides from each other.
B) The stars move in straight lines, back and forth past each other.
C) The low-mass star moves in a circular orbit around the high-mass star, which remains stationary.
D) The stars move in elliptical orbits about a common center of mass.

Question

Quizplus · Accepted Answer

In a binary star system, both stars orbit around their common center of mass. The shape of their orbits can be elliptical, and the center of mass is not fixed in either of the stars but is a point in space relative to their masses. This means that both stars, regardless of their mass difference, move in response to their mutual gravitational attraction.

How Do Two Unequal-Mass Stars in a Binary Star System