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On the cycle periods of stellar dynamos
Received 11 June 1996 / Accepted 6 December 1996
We show that the cycle periods () of slowly rotating lower main-sequence stars with well-defined periodic chromospheric activity can be parametrized by the rotation period and the convective turnover time through a relation of the form , with and . This suggests a common dynamo mechanism for slowly rotating stars lower main-sequence stars. Using a simple linear mean-field dynamo model, we are able to reproduce the observed relation if , the total difference in angular velocity along the radial direction, scales as with , and if the -coefficient scales as with . This would suggest that, with increasing rotation rate, differential rotation decreases while rapidly increases.
Key words: stars: magnetic fields stars: activity stars: late-type MHD
© European Southern Observatory (ESO) 1997
Online publication: June 5, 1998