In recent years, a number of nearby stars have been found to possess planets. Suppose, the orbital radius of such a planet is found to be 3.0 1011 m, with a period of 1000 days. Find the mass of the star.

use T^2 = 4*pi^2*r^2/GM

T and r are given, G -Universal constant of gravitation.
Compute M - mass of star