J/AJ/115/1894 J/AJ/115/1894 Eclipsing binaries and Cepheids in M31A field K Z Stanek J Kaluzny M Krockenberger D D Sasselov J L Tonry M Mateo Astron. J. 115 1894 1998 1998AJ....115.1894S J/AJ/115/1016 : Paper I. (M31B field). (Kaluzny+ 1998) http://cfa-www.harvard.edu/~kstanek/DIRECT : Direct Project Binaries, eclipsing Photometry, UBVRI Stars, diameters Stars, variable binaries: eclipsing Cepheids distance scale galaxies: individual (M 31) stars: variables: other We have undertaken a long-term project, DIRECT, to obtain the direct distances to two important galaxies in the cosmological distance ladder, M31 and M33, using detached eclipsing binaries (DEBs) and Cepheids. While rare and difficult to detect, DEBs provide us with the potential to determine these distances with an accuracy better than 5%. The extensive photometry obtained in order to detect DEBs provides us with good light curves for the Cepheid variables. These are essential to the parallel project to derive direct Baade-Wesselink distances to Cepheids in M31 and M33. For both Cepheids and eclipsing binaries, the distance estimates will be free of any intermediate steps. As a first step in the DIRECT project, between 1996 September and 1997 January we obtained 36 full nights on the Michigan-Dartmouth-MIT Observatory 1.3m telescope and 45 full/partial nights on the F. L. Whipple Observatory 1.2m telescope to search for DEBs and new Cepheids in the M31 and M33 galaxies. In this paper, second in a series, we present the catalog of variable stars, most of them newly detected, found in the field M31A [({alpha},{delta})=(11.34{deg}, 41.73{deg}), J2000.0]. We have found 75 variable stars: 15 eclipsing binaries, 43 Cepheids, and 17 other periodic, possible long-period or nonperiodic variables. The catalog of variables, as well as their photometry and finding charts, is available via anonymous ftp and the World Wide Web. The CCD frames are available upon request.

M31A Name (DIRECT VNNNN M31A in Simbad) --- RAdeg Right ascension (J2000.0) deg DEdeg Declination (J20000) deg Js Variability index (Paper I, eq. (8)) --- Per Period d Vmax V magnitude at maximum brightness mag Imax Maximum I magnitude mag Rad1 Radius of the primary component number=1 The radii are in units of the orbital separation. --- Rad2 Radius of the secondary component number=1 The radii are in units of the orbital separation. --- i Inclination angle deg e Eccentricity --- Com Comment number=2 V4636 D31A, with period P=8.181 days, is a good detached eclipsing binary (DEB) candidate, with significant eccentricity. V1555 D31A was found as V6913 D31B in Paper I, with identical period, V_max_=20.63 and I_max_=20.06. --- M31A Name (DIRECT VNNNN M31A in Simbad) --- RAdeg Right ascension (J2000.0) deg DEdeg Declination (J2000.0) deg Js Variability index --- Per Period d <V> Flux-weighted mean V magnitude mag <I> Flux-weighted mean I magnitude mag Amp Amplitude of the variation mag Com Comments number=1 Ma97: Magnier et al., Cat. <J/A+AS/126/401>, [MAP97] in Simbad Variable V2276 D31A (Ma97 108) was found as V7553 D31B in Paper I, with period P=9.482 days, <V>=20.93, and <I>=19.77. --- M31A Name (DIRECT VNNNN M31A in Simbad) --- RAdeg Right ascension (J2000.0) deg DEdeg Declination (J2000.0) deg Js Variability index --- Per Period (only in table3.dat) d Vbar Error-weighted mean V magnitude mag Ibar Error-weighted mean I magnitude mag e_Vmag Standard deviation in the V band mag e_Imag Standard deviation in the I band mag Com Comments number=1 Variables V3222, V541 and V11 of table4 where also found in Paper I. --- M31A Name (VNNNN) --- Band Band --- HJD Heliocentric Julian date d Mag Magnitude in the band (I or V) mag e_Mag rms uncertainty on Mag mag James Marcout, Patricia Bauer CDS 1998Aug12 UNKNOWN UNKNOWN From AJ electronic version J_AJ_115_1894.xml