DIRECT Distances to Nearby Galaxies Using Detached Eclipsing Binaries and Cepheids. IX. Variables in the Field M31Y Discovered with Image Subtraction

Authors:
A. Z. Bonanos,
K. Z. Stanek,
D. D. Sasselov,
B. J. Mochejska,
L. M. Macri,
J. Kaluzny

Comments: 27 pages, 11 figures, submitted to AJ; paper with high-resolution
color figures and data available at
this ftp URL and at
this http URL

The DIRECT Project aims to obtain direct distances to two Local Group
galaxies, M31 and M33, which occupy a crucial position near the bottom of the
cosmological distance ladder. The first step is to search for detached
eclipsing binaries (DEBs) and Cepheids using 1 m class telescopes to select
good candidates, which will be followed up spectroscopically on 6.5-10 m class
telescopes. In this ninth paper we present a catalog of variable stars
discovered with image subtraction in field M31Y [RA=10.97 deg, Dec=41.69 deg,
J2000.0]. The data were obtained with the FLWO 1.2 m telescope on 25 nights,
over a period of 6 months. In our search covering 22×22 arcmin we discovered 41
eclipsing binaries, 126 Cepheids, and 97 other periodic or nonperiodic
variables, including a LBV candidate, a nova and a galactic CV. The catalog of
variables, as well as their photometry and finding charts, is available
electronically via anonymous ftp and the World Wide Web. The complete set of
the CCD frames is available upon request.

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