4 Conclusions

The main goal of this work was to gather and combine astrometric and photometric data obtained by different authors in the NGC 6611 region during the past 30 years. As a result of a careful analysis, a catalogue of about 2000 stars was compiled which includes proper motions in the Hipparcos system and magnitudes, colours and extinction data in a common photoelectric system. Astrometric membership probabilities were computed and included in the catalogue, too. The data form an observational basis for further studies of this very young open cluster. The complete catalogue is available at cdsarc.u-strasbg.fr (CDS) via anonymous ftp.

Acknowledgements

We thank S. Röser for providing us with the stellar sample from AC/GSC catalogue. We thank the Karl-Schwarzschild-Observatorium Tautenburg for supplying and the MAMA team, particularly J. Guibert for measuring the plates. A. Belikov, N. Kharchenko and A. Piskunov thanks the Deutsche Forschungsgemeinschaft for financial support.