Rotational modulation and flares on RS CVn and BY Dra stars XX. Photometryand spectroscopy of CC Eri in late 1989

The active flaring binary CC Eri was studied via multi-wavelength observati ons involving multi-based photometry and ground- and space-based spectrosco py. Combining early spectroscopic data with the present implies an orbital period of P = 1.5615 days. Furthermore, the spectroscopic data suggests spe ctral types of K7 and M3 for the system. The optical photometry indicated a small spot coverage in late 1989, consistent with data taken a year later which showed CC Eri entering its brightest-to-date phase. Two flares were detected in the ultraviolet spectral data. These fares radi ated 2.7 10(31) erg and 1.6 10(31) erg in the CIV line alone, each with a t otal estimated radiative energy budget of approximate to 10(36) erg. For th e higher-temperature lines, such as CIV, there was no systematic variabilit y with phase. The lower-temperature lines show a slight indication of rotat ional modulation. However, there is a much larger scatter in the individual measurements of the MgII and CIV fluxes than would be expected from measur ement errors alone, consistent with an atmosphere showing continual small-s cale activity.