First Doppler imaging of the RS CVn binary FF UMa

Abstract

We present the first Doppler Imaging (DI) study of the chromospherically active RS CVn binary FF Ursae Majoris. New mid-resolution (R ∼ 13500) time series spectral data were acquired using the echelle spectrograph attached to the 0.4-m Kreiken Telescope at the Ankara University Kreiken Observatory. We applied a spectral subtraction technique to the Hα line to reveal the phase behavior of the chromospheric activity of the system. The results derived from DI and spectral subtraction analyses show that both components exhibit photospheric and chromospheric activity. The time series spectral data also enable us to obtain the most recent radial velocity curve of the system and re-determine the physical parameters.