Multi-cycle chromospheric activity in II Peg and V711 Tau

Abstract

In this work, we studied the Mount Wilson indexes we obtained indirectly from both IUE high and low-resolution spectra of the RS CVn-type systems II Peg (K2IV) and V711 Tau (K1IV+G5V). For both systems, we found a long-term chromospheric activity cycle related to the mean level of activity of the primary star and a shorter cycle associated to the non-axisymetric redistribution of active regions on its surface