Question

Astronomers discover an exoplanet (a planet of a star other than the Sun) that has an orbital period of 3.17 Earth years in its circular orbit around its sun, which is a star with a measured mass of 3.99 × 1030 kg. Find the radius of the exoplanet\'s orbit.

Answer 1

The radius can be calculated from the formula for the orbital time period of the planet. From the time period equation we can write,

r is the radius of Orbit, Ms is mass of the sun around which the planet revolves and G is universal gravitational constant.

Substituting values we get,

This is the radius of the exoplanets orbit.