Circular orbit speed calculator by

Calculates the circular orbit speed of a planet of negligible mass orbiting a single star.
This calculator is for any system of units in which the gravitational constant G = 1.
Such units are often used in orbit simulation software. The equation is simply

An example of a useful and natural system of units in which G = 1, is defined like this:
Unit of mass = the mass of our Sun.
Unit of distance = 1 AU = the distance of our Earth from our Sun.
Unit of time = 1 Earth year divided by (2 * pi).
Unit of velocity or speed = the average orbit speed of our Earth.

mass of star

distance of planet from star

circular orbit speed

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