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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
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:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 64 53 DIRECT eclipsing binaries in M33A table3.dat 30 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
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
Bytes Format Units Label Explanations
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)
Byte-by-byte Description of file: table3.dat table6.dat
Bytes Format Units Label Explanations
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)
Byte-by-byte Description of file: table4.dat table7.dat table9.dat table11.dat
Bytes Format Units Label Explanations
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
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.
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
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)
Byte-by-byte Description of file: table8.dat
Bytes Format Units Label Explanations
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)
Byte-by-byte Description of file: table10.dat
Bytes Format Units Label Explanations
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)
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)
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 19-Jun-2001
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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