ANALYSIS OF THE IUE SATELLITE AND THE GROUND-BASED OBSERVATIONS OF SWLACERTAE

We present UBV observations of SW Lacertae obtained in 1988. We classi fy all previous light curves into three groups according to their maxi ma. The IUE spectra of SW Lacertae are used for ultraviolet photometry and for a variation study of chromospheric activity. Five light curve s between the wavelengths of 2600 Angstrom and 3100 Angstrom are made from the low-dispersion IUE spectra. We have analyzed the UBV light cu rves and five IUE light curves independently by the modified different ial correction method of Wilson and Devinney. Evidence of chromospheri c activity is indicated by the intensity variation of the Mg II emissi on line with orbital phase.