1999A&AS..137..217Z

We present new UBV photoelectric photometry and high-resolution H_α spectroscopy of the RS CVn system σ Gem made in 1993-1994. A brief photometric analysis for the new light curves is carried out using the Wilson-Devinney method with spot approximation based on the Roche model. The result suggests the probable presence of two cool spots on the K1 III primary around the phases of φ=0.6 and φ=0.9. The spot activity is discussed in connection with the chromospheric H_α emission. The enhanced H_α core emission is found to vary with phase and shows distinct anti-correlation with the spot regions. It may be an indication for the existence of plage regions on σ Gem.