B-type pulsators in the central region of NGC 869 (h Persei)

In the course of the search for B-type pulsators in the central region of h Persei, we discovered two beta Cephei stars, Oo 692(1) and Oo 992, and one SPB star, Oo 893. The first two stars are monoperiodic pulsators with peri ods of 0.1716946 and 0.1326359 d respectively, and semi-amplitudes smaller than 0.01 mag. The light curve of Oo 893 can be described by a single 1.193 633-day period, slightly non-sinusoidal in shape, and having semi-amplitude s from 19 mmag in I to 48 mmag in U. Oo 893 is the first SPB star found in h and chi: Persei. In addition, we discovered seven other variables, includ ing three eclipsing binaries and one lambda Eri star. One of the binaries i s a W UMa-type star and a likely cluster member. We also present new UBV ph otometry for 258 stars in the field. The average reddening, estimated from the cluster colour-colour diagram, amounts to E(B - V) = 0.52 mag. A 0.1 ma g dispersion of reddenings within the cluster is also seen.