Pulsating Stars in the ASAS-3 Database. I. β Cephei Stars

We present results of an analysis of the ASAS-3 data for short-period variables from the recently published catalog of over 38 000 stars. Using the data available in the literature we verify the results of the automatic classification related to β Cep pulsators. In particular, we find that 14 stars in the catalog can be classified unambiguously as new β Cep stars. By means of periodogram analysis we derive the frequencies and amplitudes of the excited modes. The main modes in the new β Cep stars have large semi-amplitudes, between 35 and 80 mmag. Up to four modes were found in some stars. Two (maybe three) new β Cep stars are members of southern young open clusters: ASAS 164409-4719.1 belongs to NGC 6200, ASAS 164630-4701.2 is a member of Hogg 22, and ASAS 164939-4431.7 could be a member of NGC 6216. We also analyze the photometry of four known β Cep stars in the ASAS-3 catalog, namely IL Vel, NSV 24078, V1449 Aql and SY Equ. Finally, we discuss the distribution of β Cep stars in the Galaxy.