J/AJ/121/2032 Direct variables in M33A field (Mochejska+, 2001)
DIRECT distances to nearby galaxies using detached eclipsing binaries and
Cepheids. VII. Additional variables in the field M33A discovered with
image subtraction.
Mochejska B.J., Kaluzny J., Stanek K.Z., Sasselov D.D., Szentgyorgyi A.H.
<Astron. J. 121, 2032 (2001)>
=2001AJ....121.2032M 2001AJ....121.2032M
ADC_Keywords: Galaxies, nearby ; Photometry, UBV
Keywords: binaries: eclipsing - Cepheids - distance scale -
galaxies: individual (M33) - stars: variables: other
Abstract:
DIRECT is a project to directly obtain the distances to two Local
Group galaxies, M31 and M33, which occupy a crucial position near the
bottom of the cosmological distance ladder. As the first step of the
DIRECT project, we have searched for detached eclipsing binaries
(DEBs) and new Cepheids in the M31 and M33 galaxies with 1 m class
telescopes. In this paper, we present a catalog of variable stars
discovered in the data from the follow-up observations of the DEB
system D33J013346.2+304439.9 in field M33A (RA=23.55°,
DE=30.72°; J2000.0), collected with the Kitt Peak National
Observatory's 2.1 m telescope. In our search covering an area of
108arcmin2, we have found 434 variable stars: 63 eclipsing binaries,
305 Cepheids, and 66 other periodic, possible long-period, or
nonperiodic variables. Of these variables, 280 are newly discovered,
mainly short-period and/or faint Cepheids. Their light curves were
extracted using the ISIS image subtraction package. For 85% of the
variables, we present light curves in standard V and B magnitudes,
with the remaining 15% expressed in units of differential flux. We
have discovered a population of first-overtone Cepheid candidates, and
for eight of them we present strong arguments in favor of this
interpretation. We also report on the detection of a nonlinearity in
the KPNO T2KA and T1KA cameras.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 64 53 DIRECT eclipsing binaries in M33A
table3.dat 29 10 DIRECT flux eclipsing binaries in M33A
table4.dat 55 14935 Light curves of eclipsing binaries in M33A
table5.dat 60 242 DIRECT Cepheids in M33A
table6.dat 30 27 DIRECT flux cepheids in M33A
table7.dat 55 71491 Light curves of Cepheids in M33A
table8.dat 52 13 DIRECT other periodic variables in M33A
table9.dat 55 3725 Light curves of other periodic variables in M33A
table10.dat 45 50 DIRECT miscellaneous variables in M33A
table11.dat 55 10958 Light curves of miscellaneous variables in M33A
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See also:
J/AJ/121/861 : BVI photometry of central part of M33 (Macri+, 2001)
J/AJ/121/870 : BVI photometry of Variables in M33 (Macri+, 2001)
http://cfa-www.harvard.edu/~kstanek/DIRECT : DIRECT homepage
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Binary name, JHHMMSS.s+DDMMSS.s (G1)
23- 29 F7.4 d Per Period of the system
31- 35 F5.2 mag Vmag ? Maximum V band magnitude outside of eclipse
37- 41 F5.2 mag Bmag ? Maximum B band magnitude outside of eclipse
43- 46 F4.2 --- R1 Estimated primary component radius in units
of the orbital separation
48- 51 F4.2 --- R2 Estimated secondary component radius in units
of the orbital separation
53- 57 F5.2 deg Inc Estimated inclination angle of the orbit
59- 62 F4.2 --- Eccen Estimated eccentricity of the orbit
64 I1 --- Com ? Comments (G2)
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Byte-by-byte Description of file: table3.dat table6.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Name, JHHMMSS.s+DDMMSS.s (G1)
23- 29 F7.4 d Per Period
30 I1 --- Com ? Comment (G2)
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Byte-by-byte Description of file: table4.dat table7.dat table9.dat table11.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Object name, JHHMMSS.s+DDMMSS.s (G1)
23 A1 --- Filter Filter passband (1)
25- 36 F12.4 d HJD Julian date of observation
38- 47 F10.3 mag Data Observed magnitude or differential flux
49- 55 F7.3 mag e_Data Uncertainty in Data
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Note (1):
B = Indicates Data is the Johnson B passband magnitude;
V = Indicates Data is the Johnson V passband magnitude;
b = Indicates Data is the Johnson B passband differential flux;
v = Indicates Data is the Johnson V passband differential flux.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Cepheid or object name, JHHMMSS.s+DDMMSS.s (G1)
23- 28 F6.3 d Per Period of the system
30- 34 F5.2 mag Vmag ? Flux-weighted average V band magnitude
36- 40 F5.2 mag Bmag ? Flux-weighted average B band magnitude
42- 45 F4.2 mag Vamp ? The V band amplitude
47- 50 F4.2 mag Bamp ? The B band amplitude
52- 60 A9 --- Com Comments (G2)
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Variable name, JHHMMSS.s+DDMMSS.s (G1)
23- 27 F5.2 d Per Period
29- 33 F5.2 mag Vmag ? Maximum V magnitude
35- 39 F5.2 mag Bmag ? Maximum B magnitude
41- 44 F4.2 mag <Vmag> ? Flux-weighted average magnitudes
46- 49 F4.2 mag <Bmag> ? Flux-weighted average magnitudes
51- 52 A2 --- Com Comments (EB = Eclipsing binary)
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Cepheid or object name, JHHMMSS.s+DDMMSS.s (G1)
23- 27 F5.2 mag Vmag ? The average V band magnitude
29- 33 F5.2 mag Bmag ? The average B band magnitude
35- 38 F4.2 mag Vamp ? The V band amplitude
40- 43 F4.2 mag Bamp ? The B band amplitude
45 I1 --- Com ? Comment (G2)
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Global notes:
Note (G1):
The names are generated from the equatorial coordinates of the object
preceded by "D33J", separated by the declination sign:
D33JHHMMSS.s+DDMMSS.s
D33 JHHMMSS.s+DDMMSS.s in Simbad
Note (G2):
1 = A variable identified by Macri et al. (2001, Cat. J/AJ/121/861)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 19-Jun-2001