We thank D.K. Yeomans of the Jet Propulsion Laboratory for providing us ephemeris, J. Hatchell for fruitful discussions on G34.3+0.15 molecular abundances, and staff members at CSO and IRAM for their help in the observations. This research has been supported by the Centre national de la recherche scientifique, the Programme national de planétologie de l'Institut des sciences de l'univers and NSF grant AST 96-15025 to the Caltech Submillimeter Observatory.
© European Southern Observatory (ESO) 2000
Online publication: January 18, 2000