You are observing the wobble of a star caused by the orbit of a planet around that star. Which property of this system listed below most signiﬁcantly affects the period of that wobble?
A) Both the planet's orbital radius and its mass
B) Neither the planet's orbital radius or its mass
C) The planet's orbital radius
D) The planet's mass

Question

Quizplus · Accepted Answer

The period of the wobble caused by the planet's orbit around the star is related to the planet's distance from the star. This means that the planet's orbital radius has the most significant effect on the wobble period. The planet's mass does have an effect on the wobble amplitude but not on the wobble period itself. Therefore, choice C is the best answer.

You Are Observing the Wobble of a Star Caused by the Orbit