We thank our referee J. Linsky for his valuable comments, his help for the rewording of the paper and the improvements he suggested. This work has been done in the frame of INTAS cooperative project "The heliosphere in the Local Interstellar Cloud" and partly supported by the International Space Science Institute in Bern. V.I. has been also supported by the MENESR (France), ISSI (Switzerland) and by RFBR Grants N. 98-01-00955, 98-02-16759. We also thank Daniel Rucinski for fruitful discussions and Yury Malama for his Monte-Carlo code.
© European Southern Observatory (ESO) 1999
Online publication: March 10, 1999