J/AJ/117/2810 M31C eclipsing binaries and Cepheids (Stanek+, 1999)
DIRECT distances to nearby galaxies using detached eclipsing binaries and
Cepheids. III. Variables in the field M31C.
Stanek K.Z., Kaluzny J., Krockenberger M., Sasselov D.D., Tonry J.L.,
Mateo M.
<Astron. J. 117, 2810 (1999)>
=1999AJ....117.2810S 1999AJ....117.2810S
ADC_Keywords: Stars, variable ; Binaries, eclipsing ; Photometry
Keywords: binaries: close - Cepheids - distance scale -
galaxies: individual (M31) - stars: variables: other
Abstract:
We undertook 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 October we obtained 95 full/partial nights on the F. L.
Whipple Observatory 1.2 m telescope and 36 full nights on the
Michigan-Dartmouth-MIT 1.3 m telescope to search for DEBs and new
Cepheids in the M31 and M33 galaxies. In this third paper in the
series, we present the catalog of variable stars, most of them newly
detected, found in the field M31C [(RA, DE)=(11.10°, 41.42°),
J2000.0]. We have found 115 variable stars: 12 eclipsing binaries, 35
Cepheids, and 68 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 complete set of the CCD frames is available upon request.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 82 12 DIRECT eclipsing binaries in M31C
table2.dat 68 35 DIRECT Cepheids in M31C
table3.dat 73 37 DIRECT other periodic variables in M31C
table4.dat 71 31 DIRECT miscellaneous variables in M31C
table5.dat 42 2469 Light curves of eclipsing binaries in M31C
table6.dat 42 7188 Light curves of Cepheids in M31C
table7.dat 42 7634 Light curves of other periodic variables in M31C
table8.dat 42 6467 Light curves of miscellaneous variables in M31C
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See also:
http://cfa-www.harvard.edu/~kstanek/DIRECT : DIRECT project
J/AJ/115/1894 : M31A eclipsing binaries and Cepheids (Stanek+ 1998)
J/AJ/115/1016 : M31B eclipsing binaries and Cepheids (Kaluzny+ 1998)
J/AJ/118/346 : M31D eclipsing binaries and Cepheids (Kaluzny+ 1999)
J/AJ/118/2211 : M31F eclipsing binaries and Cepheids (Mochejska+ 1999)
J/AJ/122/1383 : DIRECT BVI photometry in M31 (Mochejska+, 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- M31C Variable name (DIRECT VNNNN M31C in Simbad)
13- 19 F7.4 deg RAdeg Right ascension (J2000.0)
21- 27 F7.4 deg DEdeg Declination (J2000.0)
29- 35 F7.4 d Per Period
37- 41 F5.2 mag Vmax Maximum Johnson V magnitude
43- 47 F5.2 mag Imax ? Maximum Cousins I magnitude
49- 53 F5.2 mag Bmax Maximum B magnitude
55- 58 F4.2 --- R1 First component radius (1)
60- 63 F4.2 --- R2 Second component radius (1)
65- 66 I2 deg i Inclination angle
68- 71 F4.2 --- e Ellipticity
73- 82 A10 --- com Individual Comments (2)
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Note (1): in orbital separation units
Note (2):
V9037 D31C with period P=5.7735days is a good detached eclipsing
binary (DEB) candidate, with significant eccentricity.
V12594 D31C was found in Paper I (Cat. J/AJ/115/1016) as V2763 D31B,
with P=2.302 days, Vmax=20.51, and Imax=20.84.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- M31C Variable name (DIRECT VNNNN M31C in Simbad)
13- 19 F7.4 deg RAdeg Right ascension (J2000.0)
21- 27 F7.4 deg DEdeg Declination (J2000.0)
29- 34 F6.3 d Per Period
36- 40 F5.2 mag <Vmag> Flux-weighted mean Johnson V magnitude
42- 46 F5.2 mag <Imag> ? Flux-weighted mean Cousins I magnitude
48- 52 F5.2 mag <Bmag> ? Flux-weighted mean Johnson B magnitude
54- 57 F4.2 mag A V-band amplitude of the variation
59- 68 A10 --- Com Individual Comments (1)
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Note (1): Ma97 NN designate objects in Magnier et al., 1997,
Cat. J/A+AS/126/401, [MAP97] in Simbad
V10846 D31C was found in Paper I (Cat. J/AJ/115/1016) as V1562 D31B,
with P=7.784 days, =21.20, and =20.43.
V9544 D31C was found as V643 D31B,
with P=7.889 days, =20.39, and =19.52.
V8771 D31C was found as V129 D31B,
with P=8.242 days, =20.74, and =19.58.
V12902 D31C was found as V2977 D31B,
with P=8.518 days, =21.80, and =20.40.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- M31C Variable name (DIRECT VNNNN M31C in Simbad)
13- 19 F7.4 deg RAdeg Right ascension (J2000.0)
21- 27 F7.4 deg DEdeg Declination (J2000.0)
29- 33 F5.1 d Per Period
35- 39 F5.2 mag Vmag Error-weighted mean Johnson V magnitude
41- 45 F5.2 mag Imag ? Error-weighted mean Cousins I magnitude
47- 51 F5.2 mag Bmag ? Error-weighted mean Johnson B magnitude
53- 56 F4.2 mag e_Vmag Standard deviation in Johnson V band
58- 61 F4.2 mag e_Imag ? Standard deviation in Cousins I band
63- 66 F4.2 mag e_Bmag ? Standard deviation in Johnson B band
68- 73 A6 --- Com Comments
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- M31C Variable name (DIRECT VNNNN M31C in Simbad)
13- 19 F7.4 deg RAdeg Right ascension (J2000.0)
21- 27 F7.4 deg DEdeg Declination (J2000.0)
29- 33 F5.2 mag Vmag Mean Johnson V magnitude
35- 39 F5.2 mag Imag ? Mean Cousins I magnitude
41- 45 F5.2 mag Bmag ? Mean Johnson B magnitude
47- 50 F4.2 mag e_Vmag Standard deviation in Johnson V band
52- 55 F4.2 mag e_Imag ? Standard deviation in Cousins I band
57- 60 F4.2 mag e_Bmag ? Standard deviation in Johnson B band
62- 71 A10 --- Com Comments (1)
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Note (1): Variable V14370 D31C was also found in Paper I (Cat. J/AJ/115/1016).
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Byte-by-byte Description of file: table[5678].dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- M31C Variable name (DIRECT VNNNN M31C in Simbad)
14 A1 --- Band [BVI] Band (Johnson BV and Cousins I)
16- 27 F12.4 d HJD Heliocentric Julian date
30- 35 F6.3 mag mag Magnitude in band "Band"
38- 42 F5.3 mag e_mag rms uncertainty on mag
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History: From electronic version
(End) James Marcout, Patricia Bauer [CDS] 14-Sep-1999