![]() | ![]() |
Astron. Astrophys. 332, 102-110 (1998) AcknowledgementsThe research grants from OTKA No. T 021074 and T 015759 are acknowledged. The authors are indebted to Horace Smith for comments and suggestions in his referee report. The quality of the paper remarkably improved. ![]() ![]() ![]() ![]() © European Southern Observatory (ESO) 1998 Online publication: March 10, 1998 ![]() |