You have observed the wobble in the velocity curves of two otherwise identical stars. Star A has a period of 6 months and Star B has a period of 1 year. What can you say about these stars?
A) Star B must have a planet like Earth.
B) Star A's planet is more massive than Star B's planet.
C) It is impossible to say anything about the planets orbiting these stars.
D) Star A's planet must be closer than Star B's planet.

Question

Quizplus · Accepted Answer

The period of the wobble in the velocity curve is related to the period of the planet's orbit around the star. Since Star A has a shorter period, its planet must be closer to the star than Star B's planet. Therefore, Star A's planet must be closer than Star B's planet. It is impossible to determine the mass or even the existence of the planets orbiting these stars without more information.

You Have Observed the Wobble in the Velocity Curves of Two