SOHO is a mission of international cooperation between ESA and NASA. The CDS project is supported by the United Kingdom PPARC. We would like to thank M.Landini for useful discussions and J.M. Delouis for his help in the radio data reduction. We would like to thank also Dr. K. Shibasaki for very useful comments on the original manuscript. One of the authors (EL) acknowledges financial support from the Italian Space Agency (ASI contract RS-96.141).
© European Southern Observatory (ESO) 1999
Online publication: July 16, 1999