Question 6.

Question

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Scientists are observing and recording data for two different planets, planet X and planets suar planet orbits a different star. The planets have the same mass. The scientists record the folloving data.
Star X - Planet X Star Y - Planet Y
100
100
390
260
[
7. Look at the image to the left. Read carefully. Mark your answer choice here
Distance (millions of kilometers)
Orbital period of the planet
(Earth days)
Which of the following statements is most likely true?
The star close to planet Y has more mass
B.
The star close to planet Y has less mass
c.
The star close to planet Y is cooler.
D.
The star close to planet Y is hotter.

Answer 1

To determine the relationship between the mass, temperature, and distance of the stars relating to the planets, we need to consider Kepler's laws of planetary motion and the properties of stars.

Since planet Y orbits at a greater distance (260 million kilometers) compared to planet X (100 million kilometers) and has a longer orbital period (390 Earth days compared to 100 Earth days), it suggests that planet Y is further from its star compared to planet X from its star.

The gravitational force, which dictates the orbital period and distance, depends on the mass of the star. If the star around planet Y were more massive, the planet would have to orbit closer than it does. Therefore, for planet Y to have a longer orbital period while being at a further distance, the star it orbits must be less massive.

Based on this reasoning, the most likely true statement is:

B. The star close to planet Y has less mass.

This is because a less massive star would allow for a longer orbital period at a greater distance.