Exact solution of the double-Kerr equilibrium problem

We present concise analytic expressions for the Komar masses and angular momenta of the balancing Kerr-NUT constituents in the double-Kerr solution which complement the equilibrium formulae previously obtained (Manko V S, Ruiz E and Sanabria-Gómez J D 2000 Class. Quantum Grav. 17 3881). A rigorous proof of the non-existence of equilibrium states of two Kerr black holes with positive masses is given.