High resolution echelle-Reticon observations covering all orbital phases of the bright RS CVn stars (sigma) Gem and HR 5110 have been obtained. Nine spectra with 0.16 (ANGSTROM) resolution show that the core of H(alpha) in (sigma) Gem varies with orbital phase in agreement with the spot zones identified by Fried et al. (1983) and also that the H(alpha) brightness of a zone changes in time. Neutral metal lines in the same echelle order have been studied to investigate the properties of the spots. A new method is described to determine spot areas and temperatures from temperature-sensitive metal lines. The lack of observed metal line variation in the normal spot zones requires a temperature difference between spot and photosphere greater than 1000 K and spot area less than 20% of the disk. In an unusual event, a warmer short-lived spot appeared in the region between zones.; Lines from the cool secondary of HR 5110 have been detected on 16 spectra with resolution 0.3 (ANGSTROM). New mass and light ratios (M(,2)/M(,1) = 0.54, F(,2)/F(,1) = 0.20) have been determined. Effective temperatures of 6750 K and 4700 K for the primary and secondary respectively have been estimated from the line spectrum. The extremely weak H(alpha) absorption profile of HR 5110 revealed an emission profile after a comparison composite spectrum was subtracted. The strong, variable, residual H(alpha) emission has two components: a narrow and steady emission peak and a variable and extremely broad component. A simple model with Stark broadening in a dense chromosphere of the K star can explain the broad component, while the narrow peak appears to come from an accretion disk around the primary. |