Tuominen, Ilkka

Contact Email: Ilkka.Tuominen@oulu.fi
Institute: University of Oulu
First Coauthor: Svetlana Berdyugina
Institute: University of Oulu
Subject Area: Other (Please Specify Below)
Waveband: Optical
Technique: Imaging (Doppler)
Other: Stellar activity cycles
Presentation: Poster Display
Title: Switching active longitudes in single stars and binaries
Abstract: We analyse new photometric data for a sample of active single and binary stars and confirm the presence of permanent active longitudes on RS CVn stars first reported by Berdyugina & Tuominen (1998). Previously we found that the dominant activity regularly switched between the active longitudes indicating a new kind of stellar activity cycles related to the non-axisymmetric spot distribution. We suggested these switches to be a tracer of such cycles. With the new photometric data collected to the date we expand the sample of stars with the similar behaviour and for the previously investigated stars find a good agreement between the observed and expected spot evolution.