A search for rapid variability of H-alpha with a time resolution from 30 to 45 seconds is performed for Phi Per. In total, 42 spectra in H-alpha were obtained during three nights. Results show the presence of rapid irregular ...

We present extensive UBVRI photometry of the active RS CVn binary DM UMa obtained at two different observatories over 1988-2008. We find the light curve of the star to be highly variable. The long-term photometry shows no ...