![]() | ![]() |
Astron. Astrophys. 340, 371-380 (1998) AcknowledgementsThis research is supported in part by the contract ARC 94/99-178, and a project funded by SSTC/ Prodex. We would like to thank Jean Surdej for reading the manuscript, and the referee for useful comments. ![]() ![]() ![]() ![]() © European Southern Observatory (ESO) 1998 Online publication: November 9, 1998 ![]() |