6 Conclusion

In the course of our program dedicated to microlensing events, we have devoted a fraction of observing time to the search for variable stars in six directions of the Galactic plane. This exploratory campaign, that lasted three months, led to the discovery of 1362 variable stars. Among them we identified 9 Cepheids, 19 RR Lyræ, 34 Miras, 176 eclipsing binaries and 266 Semi-Regular variable stars. We have set up a catalogue of all of the 1362 stars and cross-identified it with several other catalogues. In particular a comparison with the GCVS and the CKS91 catalogues shows that only a small fraction ($\sim$15%) of the objects that we have identified appear in those two. Among the stars most appropriate to be used as distance indicators, the Cepheids turned out to be too few to warrant a particular study. As far as RR Lyræ are concerned, we have determined their mean distance and found it to be $\sim$5 kpc. Yet the statistics being quite limited, we are considering pursuing this effort by launching a longer search for variable stars based on the results of this first campaign.

Acknowledgements

The WCSTools package was made available to us thanks to the work of Doug Mink, NASA/GSFC, Harvard. The Skycat/Gaia tool is the result of a joint effort by the computer staff of ESO Garching and from the Starlink Project, UK.