A planet ( P_1) is moving around the star of mass 2 M in the orbit of radius R. Another planet ( P_2) is moving around another star of mass 4 M in a…

A planet $\displaystyle \left(\mathrm{P}_1\right)$ is moving around the star of mass $\displaystyle 2 M$ in the orbit of radius $\displaystyle R$. Another planet $\displaystyle \left(\mathrm{P}_2\right)$ is moving around another star of mass $\displaystyle 4 M$ in a orbit of radius $\displaystyle 2 R$. Ratio of time periods of revolution of $\displaystyle P_2$ and $\displaystyle P_1$ is $\displaystyle \_\_\_\_$.