The authors wish to thank H.S. Hudson for providing the high frequency ACRIM power spectrum, and C. Fröhlich for providing the low frequency ACRIM data and, especially, for his useful comments on the paper. This work has been made possible thanks to the financial support from the Spanish CICYT under grants ESP91-1441 and PB91-0530. M.C. Rabello Soares acknowledges partial support received from the Brazilian Institution: CNPq (202504/91-3).
© European Southern Observatory (ESO) 1997
Online publication: July 3, 1998