Flip-flops of FK Comae Berenices

  title={Flip-flops of FK Comae Berenices},
  author={Thomas Hackman and J. Pelt and Maarit J. Mantere and Lauri Jetsu and Heidi Korhonen and Thomas Granzer and Perttu Kajatkari and Jyri J. Lehtinen and Klaus G. Strassmeier},
  journal={Astronomy and Astrophysics},
Context. FK Comae Berenices is a rapidly rotating magnetically active star, the light curve of which is modulated by cool spots on its surface. It was the first star where the “flip-flop” phenomenon was discovered. Since then, flip-flops in the spot activity have been reported in many other stars. Follow-up studies with increasing length have shown, however, that the phenomenon is more complex than was thought right after its discovery. Aims. Therefore, it is of interest to perform a more… 
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The starspots on the surface of many chromospherically active binary stars concentrate on long-lived active longitudes separated by 180°. Shifts in activity between these two longitudes, the
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Aims. The rapidly rotating active stars FK Com and HD 199178 are investigated using extensive long-term photometry. The data set includes previously unpublished photometry, obtained at the Rozhen
Study of FK Comae Berenices - VI. Spot motions, phase jumps and a flip-flop from time-series modelling
Aims. Time-series spot modelling was used to follow the longitude changes of active regions responsible for the light variability of FK Com between 1987-2004. Methods. The photometric data are
Study of FK Comae Berenices V. Spot evolution and detection of surface differential rotation
Aims. We investigate the spot evolution and the surface differential rotation of the single late-type giant FK Com. Methods. A total of 18 new surface temperature maps of FK Com are calculated with
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We have studied the long-term spot activity of the RS CVn star II Peg by means of Doppler imaging based on spectroscopy and time series analysis of photometry. We present 28 Doppler imaging
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