Ultraviolet and optical line profile variations in the spectrum of epsilonPersei

The rapid variable star, epsilon Per (B0.5 IV-III), displays the largest am plitude profile fluctuations known among the growing number of massive, spe ctrum-variable stars. Here we present an analysis of a continuous 5 day run of IUE UV spectroscopy, and we show for the first time that the systematic , blue-to-red moving patterns observed in high-quality optical spectra are also present in the UV photospheric lines. We present cross-correlation fun ctions of the individual spectra with that of a narrow-lined standard that produce a high signal-to-noise ratio representation of the blue-to-red movi ng bump patterns found in individual lines. We then use time series analysi s methods to determine the periodic components of the profile variations (a fter reregistering the spectra to correct for binary motion). There are at least six periods present (ranging from 8.46 to 2.27 hr), and most of these signals are also found in optical line variations observed in 1986 (althou gh the relative amplitudes have changed significantly). Furthermore, analys is of a shorter time series of IUE spectra from 1984 shows that similar per iods were present then. We also present H alpha and He I lambda 6678 profil es obtained with the Georgia State University Multi-Telescope Telescope, wh ich were made simultaneously with IUE, and we show that the prove variation s are essentially identical in the UV and optical ranges. We rule out rotat ional modulation and circumstellar gas obscuration as possible causes, and we suggest instead that the variations are the result of photospheric nonra dial pulsations of relatively low degree (l = 3-5). There were significant changes (similar to 10%) in the equivalent widths of the UV stellar wind li nes during the IUE run, and we suggest that wind strengthening events are r elated to episodes of large-amplitude, constructive interference between th e NRP modes. Thus, intermode beating may play an important role in promotin g wind loss from massive stars.