B. I. Stepanov Institute of Physics of NAS of Belarus, Belarus

Both Kerr and Newman-Unti-Tamburino (NUT) metrics are axially symmetric vacuum solutions of Einstein equation. While the physical interpretation of the Kerr parameter as an angular momentum per unit mass of a rotating black hole is well known, the interpretation of the NUT parameter (so called, NUT charge or gravitomagnetic charge) is quite elusive. Mostly, the last is considered as a semi-infinite linear source of a pure angular momentum [1] or the twist parameter of the surrounding vacuum spacetime or electromagnetic universe [2]. The investigation of rotating black hole with additional NUT parameter can allow to compare the influence of each parameter solely and to estimate their complementary effects. In this report we apply the tetrad method developed by Tetrode-Weyl-Fock-Ivanenko to derive the Maxwell equations in Kerr-NUT geometry. The separation of the variables has been performed and the solutions have been found for angular and radial variables in terms of confluent Heun functions. The quantization rule for separation constant has been studied and the contribution of the NUT parameter has been distinguished. We demonstrated that NUT parameter $a$ determines the shift of the total angular momentum by $\pm 2 \omega a$. The radial functions have been shown to have a structure of outgoing and ingoing waves. [1] W. Bonner, Math.Proc.Cambridge Phil.Soc. pp.145–151 (1969). [2] A. Al-Badawi and M. Halilsoy, Gen.Relativ.Gravit. 38, 1729 (2006).