J/AJ/115/1016 M31B eclipsing binaries and Cepheids (Kaluzny+ 1998)
DIRECT distances to nearby galaxies using detached eclipsing binaries and
Cepheids. I. Variables in the field M31B
Kaluzny J., Stanek K.Z., Krockenberger M., Sasselov D.D., Tonry J.L.,
Mateo M.
<Astron. J. 115, 1016 (1998)>
=1998AJ....115.1016K 1998AJ....115.1016K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Binaries, eclipsing ; Photometry
Keywords: binaries: eclipsing - Cepheids - Galaxies: distances and redshifts -
Galaxies: individual (M31) - Local Group
Abstract:
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,
first in a series, we present the catalog of variable stars, most of
them newly detected, found in the field M31B
[(α,δ)=(11.20°, 41.59°), J2000.0]. We have found
85 variable stars: 12 eclipsing binaries, 38 Cepheids, and 35 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:
http://cfa-www.harvard.edu/~kstanek/DIRECT.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 12 DIRECT miscellaneous variables in M31B
table2.dat 59 38 DIRECT Cepheids in M31B
table3.dat 68 8 DIRECT other periodic variables in M31B
table4.dat 67 27 DIRECT miscellaneous variables in M31B
table5.dat 34 2375 Light curves of eclipsing binaries in M31B
table6.dat 34 7481 Light curves of Cepheids in M31B
table7.dat 34 1491 Light curves of other periodic variables in M31B
table8.dat 34 5315 Light curves of miscellaneous variables in M31B
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See also:
J/A+AS/126/401 : M 31 Cepheids periods (Magnier+ 1997)
J/AJ/115/1894 : M31A eclipsing binaries and Cepheids (Stanek+ 1998)
J/AJ/117/2810 : M31C eclipsing binaries and Cepheids (Stanek+, 1999)
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)
http://cfa-www.harvard.edu/~kstanek/DIRECT : DIRECT Project
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- M31B Variable name (DIRECT VNNNN M31B in Simbad)
7- 13 F7.4 deg RAdeg Right ascension (J2000.0)
15- 21 F7.4 deg DEdeg Declination (J2000.0)
23- 27 F5.2 --- Js Variability index JS
29- 34 F6.4 d Per Period
36- 40 F5.2 mag Vmax Maximun V magnitude of the system outside eclipse
42- 46 F5.2 mag Imax Maximun Ic magnitude of the system outside eclipse
48- 51 F4.2 --- Rad1 Radius of the binary first component (1)
53- 56 F4.2 --- Rad2 Radius of the binary second component (1)
58- 59 I2 deg i Inclination angle of the binary orbit to the
line of sight
61- 64 F4.2 --- e Eccentricity of the orbit
66- 72 A7 --- Com Comments (2)
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Note (1): The radius are in units of the orbital separation
Note (2): Ma97 NNN, NNN identification number assigned by
Magnier et al., 1997, Cat. J/A+AS/126/401
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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- 5 A5 --- M31B Variable name (DIRECT VNNNN M31B in Simbad)
7- 13 F7.4 deg RAdeg Right ascension (J2000.0)
15- 21 F7.4 deg DEdeg Declination (J2000.0)
23- 26 F4.2 --- Js Variability index JS
28- 33 F6.3 d Per Period
35- 39 F5.2 mag <Vmag> Flux-weighted mean V magnitude
41- 45 F5.2 mag <Imag> ? Flux-weighted mean Ic magnitude
47- 50 F4.2 --- A Amplitude of the variation
52- 59 A8 --- Com Comments (1)
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Note (1): Ma97 NNN, NNN identification number assigned by
Magnier et al., 1997, Cat. J/A+AS/126/401
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Byte-by-byte Description of file: table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- M31B Variable name (DIRECT VNNNN M31B in Simbad)
7- 13 F7.4 deg RAdeg Right ascension (J2000.0)
15- 21 F7.4 deg DEdeg Declination (J2000.0)
23- 27 F5.2 --- Js Variability index JS
29- 34 F6.3 d Per ? Period (only in table3.dat)
36- 40 F5.2 mag <Vmag> Error-weighted mean V magnitude
42- 46 F5.2 mag <Imag> ? Error-weighted mean Ic magnitude
48- 51 F4.2 mag e_<Vmag> rms uncertainty on <Vmag>
53- 56 F4.2 mag e_<Imag> ? rms uncertainty on <Imag>
58- 68 A11 --- Com Comments
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Byte-by-byte Description of file: table5.dat table6.dat table7.dat table8.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- M31B Variable name (DIRECT VNNNN M31B in Simbad)
7 A1 --- Band [IV] Band (Johnson V or Cousins I)
9- 20 F12.4 d HJD Heliocentric Julian date
22- 27 F6.3 mag mag Magnitude
29- 34 F6.3 mag e_mag rms uncertainty on mag
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History: From the Astronomical Journal electronic version
(End) James Marcout, Patricia Bauer [CDS] 06-Apr-1998