2003A&A...403..205A

The quasisimultaneous electrophotometric, polarimetric and spectroscopic observations of the chromospherically active binary MS Ser are presented. The photometric variability of the star can be described completely by a zonal spottedness model. Spotted regions occupy up to 21% of the total stellar surface. The temperature difference between the unspotted photosphere and starspots is about 1300K. Starspots are localized at the middle latitudes. We detected the broad-band linear polarization of the stellar light and its rotational modulation connected with the local magnetic region on the stellar surface. We suspect that there is a space connection between plages, magnetic regions and the mostly spotted stellar longitudes.