SIMBAD references

Some active stars show a so-called flip-flop phenomenon in which the main spot activity periodically switches between two active longitudes that are 180° apart. In this paper we study the flip-flop phenomenon by converting results from dynamo calculations into long-term synthetic photometric observations, which are then compared to the real stellar observations. We show that similar activity patterns as obtained from flip-flop dynamo calculations, can also be seen in the observations. The long-term light-curve behaviour seen in the synthesised data can be used for finding new stars exhibiting the flip-flop phenomenon.