Stellar butterfly diagrams
Svetlana V. Berdyugina (Institute of Astronomy, ETH Zürich)
Cyclic latitude migration of sunspot zones results in the famous butterfly
diagram which reflects the dynamo process in the Sun. In the presence of
differential rotation the latitude variations induce longitude migration of
non-axisymmetric fields. Therefore, migration of long-lived spot activity
regions (active longitudes) combined with the information on the differential
rotation can be used to deduce butterfly diagrams. Here I present a new
technique which is able to recover stellar butterfly diagrams from the analysis
of long-term photometric data and Doppler images. I discuss the results for
different types of stars and compare them with the solar counterpart.
http://www.astro.phys.ethz.ch/staff/berdyugina/berdyugina_nf.html