Kepler third law T^2 = (4 pi^2 / GM) a^3; circular-orbit dynamic equilibrium

Kepler third law / circular-orbit framework (Kepler 1619 Harmonices Mundi V; Newton 1687 Principia Mathematica I.III.IV-VII). Setup: for a planet of mass m_p in circular orbit at semi-major axis a around a star of mass M_star, force…