Possible chromospheric activity cycles in II Peg, UX Ari and V711 Tau

BUCCINO, ANDREA P.; MAUAS, P. J. D.

Saint Andrews, Escocia, Reino Unido

Congreso; 15th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun; 2008

Saint Andrews University

In this work, we study the Mount Wilson indices we obtained indirectly from both IUE high and low resolution spectra of the RS CVn-type systems II Peg (K2IV), UX Ari (K0IV+G5V) and V711 Tau (K1IV+G5V), which were extensively observed by IUE from 1978 to 1996. We analize the activity signatures, which correspond to the primary star, with the Lomb-Scargle periodogram. The data of II Peg suggest a chromospheric cycle of near 20 years. We also found a chomospheric activity cycle of near 18 years and a 3-year-long flip-flop cycle for V711 Tau. Finally, we obtained a chromospheric cycle of near 6 years for UX Ari.