NEW ASPECTS OF THE VARIABILITY OF BETA-CEP

A few years ago, beta Cep - a prototype of hot rapid spectral and ligh t variables which are generally believed to pulsate - was also confirm ed to be a Be star and a magnetic Bp star. Our investigation of red Re ticon spectra of beta Cep obtained during the presence of the Ho emiss ion revealed a new surprising aspect of the variability of this star: Radial velocity of the double H alpha emission, measured on the wings of the emission line, varies in antiphase to absorption radial-velocit y with the known period of 0.(d)19048. It also varies on a longer time scale: over the period from 1994 to 1996 the mean radial velocity of the H alpha emission increased from 24 to 63 km s(-1). Possible seriou s impact of these finding on the current interpretation of the beta Ce p phenomenon is briefly discussed. It is also found that beta Cep is r apidly approaching the periastron of its 90-yr orbit, much sooner than predicted, and an intensive monitoring is called for.