A Unique Formula for Calculating the Rotational Period of Planet and Star.

This paper reports a formula derived from two assumptions: amplification factor X and rotational resistance. The amplification factor and rotational resistance are expressed in the process of a celestial body changing from its inherent state to its non-inherent rotation state. So-called non-inherent state of object is its orbital motion state. The rotational mass, the rotational radius and the gravity on the its surface are three decisive factors that determine the rotational period of an object.