![]() | ![]() |
Astron. Astrophys. 364, 763-768 (2000) AcknowledgementsWe thank Sylvie Cabrit (the referee) for helpful comments about this paper. The work of AR and JC was supported by the CONACyT grants 32753-E and 27546-E. LFR acknowledges support from DGAPA (UNAM) and CONACyT (México). ![]() ![]() ![]() ![]() © European Southern Observatory (ESO) 2000 Online publication: January 29, 2001 ![]() |