Optical identifications of five INTEGRAL hard X-ray sources in the Galactic plane

The results of optical identifications of five hard X-ray sources in the Galactic plane from the INTEGRAL all-sky survey are presented. The X-ray data on one source (IGR J20216+4359) are published for the first time. The optical observations were performed with the 1.5-m RTT-150 telescope (Turkish National Observatory, Antalya, Turkey) and the 6-m BTA telescope (Special Astrophysical Observatory, Nizhny Arkhyz, Russia). A blazar, three Seyfert galaxies, and a high-mass X-ray binary are among the identified sources.