You observe a star very similar to our own Sun in size and mass. This star moves very slightly back and forth in the sky once every 4 months, and you attribute this motion to the effect of an orbiting planet. What can you conclude about the orbiting planet?
A) The planet must be closer to the star than Earth is to the Sun.
B) The planet must have a mass about the same as the mass of Jupiter.
C) The planet must be farther from the star than Neptune is from the Sun.
D) You do not have enough information to say anything at all about the planet.

Question

Quizplus · Accepted Answer

The star is moving back and forth in the sky, which means it is experiencing gravitational influence from an orbiting planet. If the planet had a mass significantly greater than Jupiter, the star's motion would be more pronounced. If the planet was closer to the star than Earth is to the Sun, the star's motion would be more rapid. Therefore, the best conclusion we can draw is that the planet is closer to the star than Earth is to the Sun.

You Observe a Star Very Similar to Our Own Sun