A CCD search for variable stars of spectral type B in the Northern Hemisphere open clusters. IV. NGC 663

We present results of the variability search in the field of the young open cluster NGC 663. In addition to the one P Cep-type variable known in this cluster, we found another one. It is a mono-periodic pulsator changing brig htness with a period of 0.27640 d. In total, 19 new variables were discover ed and the variability of 5 other ones was confirmed. Out of all 24 variables in the observed field, 21 are probable cluster memb ers. One SPB candidate and three eclipsing or ellipsoidal variables could b e classified. Moreover, ten out of fourteen Be stars we observed vary in br ightness. Only one of them shows periodic variations of the h Ed-type, whil e the remaining ones exhibit irregular changes with the range up to 0.4 mag in the le band. We also provide new VIC photometry of 477 stars in the field of the cluster and check the consistence of the present photometry with cluster parameter s derived earlier. The average cluster E(V - I-C) color excess amounts to a bout 0.92 mag.