Cool Stars 14 - Submitted Abstract # 142
This version created on 05 October 2006

Flip-flop phenomenon in active stars


Silva Jarvinen, Astrophysikalisches Institut Potsdam
Heidi Korhonen, Astrophysikalisches Institut Potsdam
Klaus Strassmeier, Astrophysikalisches Institut Potsdam

In many active stars the spots concentrate on two permanent active
longitudes which are 180  degrees apart.  In some of these stars the
dominant part of the spot activity changes the longitude every few
years.  This so-called flip-flop phenomenon has been reported on
single giants, binary stars, young solar type stars and the Sun
itself.  Even though this effect has been detected on many types of
active stars, still only about ten stars are known to exhibit it.
This makes statistical comparison of the flip-flop properties and
other stellar parameters impossible.  Studying these correlations is
important for constraining the recent dynamo models that start to be
able to explain this phenomenon.  Here we present results from an
investigation where we have studied the long-term photometry of a
sample of active stars, binaries and single stars alike, to see
whether or not they show the flip-flop phenomenon.  The aim of this
research is to help constrain the dynamo models by studying
correlations between the flip-flop period and other stellar
parameters.

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