The DIRECT Project: Catalogs of Stellar Objects in Nearby Galaxies. I. The Central Part of M33

The DIRECT project aims to determine direct distances to two important galaxies in the cosmological distance ladder-M31 and M33-using detached eclipsing binaries (DEBs) and Cepheids. The search for these variables requires time-series photometry of large areas of the target galaxies and yields magnitudes and positions for tens of thousands of stellar objects, which may be of use to the astronomical community at large. During the first phase of the project, between 1996 September and 1997 October, we were awarded 95 nights on the F. L. Whipple Observatory 1.2 m telescope and 36 nights on the Michigan-Dartmouth-MIT 1.3 m telescope to search for DEBs and Cepheids in the M31 and M33 galaxies. This paper, the first in our series of stellar catalogs, lists the positions, three-color photometry, and variability indices of 57,581 stars with 14.4<V<23.6 in the central part of M33. The catalog is available from our FTP site. Based on observations collected at the Fred L. Whipple Observatory 1.2 m telescope and at the Michigan-Dartmouth-MIT 1.3 m telescope.