We gratefully thank R. Launhardt for supporting the 1.3 mm observation at the SEST telescope. B. Stecklum thanks P. Bouchet for assistance in reducing the single-channel photometry. We thank the MPIA time allocation commitee for granting observing time at the 2.2-m telescope on November 1994 and March 1998. A. Burkert acknowledges support through the Max Planck Society.
© European Southern Observatory (ESO) 2000
Online publication: December 8, 1999