X iv : a st ro - p h / 02 01 37 7 v 1 2 3 Ja n 20 02 Difference Image Analysis of the OGLE - II Bulge Data . III . Catalog

We present the first edition of a catalog of variable stars from OGLE-II Galac-tic Bulge data covering 3 years: 1997–1999. Typically 200–300 I band data points are available in 49 fields between −11 and 11 degrees in galactic longitude, total-ing roughly 11 square degrees in sky coverage. Photometry was obtained using the Difference Image Analysis (DIA) software and tied to the OGLE data base with the DoPhot package. The present version of the catalog comprises 221,801 light curves. In this preliminary work the level of contamination by spurious detections is still about 10%. Parts of the catalog have only crude calibration, insufficient for distance determinations. The next, fully calibrated, edition will include the data collected in year 2000. The data is accessible via FTP. Due to the data volume, we also distribute DAT tapes upon request.