One of the authors (V.A.K.) is very grateful to D.O. Gough, J.T. Hoeksema, G.R. Isaak, M.Yu. Khlopov, B.V. Komberg, S. Koutchmy, V.M. Lyuty, J.-C. Pecker, V. Petrosian, M.V. Sazhin, P.H. Scherrer, P.A. Sturrock and H.B. van der Raay for many interesting and stimulating discussions on the topic of this paper, he had with them over the last decade. Both authors are greatly indebted to H.B. van der Raay for many fruitful questions and comments to the original manuscript which resulted in a substantial improvement of the statistical analysis and the paper itself. This work was supported in part by the International Science Foundation (grants No. UCU000 and UCU200).
© European Southern Observatory (ESO) 1997
Online publication: June 30, 1998