EMISSION-LINE VARIATIONS IN RS CANUM VENATICORUM TYPE BINARIES

Photoelectric spectrophotometry of the H&K and Hα emission lines in six close binaries is reported. UX Ari, RS CVn, Z Her, AR Lac, LX Per and SZ Psc were observed throughout 1974 with a rapid-scanning spectro-photometer attached to the 1-m reflector at Northwestern University. Composite emission-absorption equivalent widths were obtained for both spectral intervals in each system.Analysis of these data revealed a marginal relation between emission intensity and phase in three systems: UX Ari, RS CVn and Z Her. These systems also exhibit photometric wave-like distortions in their light curves. The observed mean phases of maximum emission intensity were found to coincide with the phases of photometric wave minimum in all three. The remaining systems exhibited basically random emission intensity variation. Extensive chromospheric activity on the later-type component in each system can account for both the current spectrophotometric results and the photo-metric peculiarities. © 1978 Royal Astronomical Society.