J/AJ/122/2477 DIRECT variables in M33B field (Mochejska+, 2001)
DIRECT distances to nearby galaxies using detached eclipsing binaries and
Cepheids.
VIII. Additional variables in the field M33B discovered with image subtraction.
Mochejska B.J., Kaluzny J., Stanek K.Z., Sasselov D.D., Szentgyorgyi A.H.
<Astron. J. 122, 2477 (2001)>
=2001AJ....122.2477M 2001AJ....122.2477M
ADC_Keywords: Galaxies, nearby ; Stars, variable ; Photometry, UBV
Keywords: binaries: eclipsing - Cepheids - distance scale -
galaxies: individual (M33) - stars: variables: other
Abstract:
DIRECT is a project to obtain directly 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 1m class
telescopes. In this eighth paper we present a catalog of variable
stars discovered in the data from the follow-up observations of DEB
system D33J013337.0+303032.8 in field M33B [(RA,DE)=(23.48°,
30.57°), J2000.0], collected with the Kitt Peak National
Observatory 2.1m telescope. In our search covering an area of
108arcmin2 we have found 895 variable stars: 96 eclipsing binaries,
349 Cepheids, and 450 other periodic, possibly long-period or
nonperiodic variables. Of these variables 612 are newly discovered.
Their light curves were extracted using the ISIS image subtraction
package. For 77% of the variables we present light curves in standard
V and B magnitudes, with the remaining 23% expressed in units of
differential flux. We have discovered a population of first-overtone
Cepheid candidates, and for six of them we present strong arguments in
favor of this interpretation. The catalog of variables, as well as
their photometry (about 9.2x104 BV measurements) and finding charts,
is available electronically via anonymous ftp and the World Wide Web.
The complete set of the CCD frames is available upon request.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 65 89 DIRECT eclipsing binaries in M33B
table2.dat 32 7 DIRECT flux eclipsing binaries in M33B
table3.dat 55 9892 Light curves of eclipsing binaries in M33B
table4.dat 54 292 DIRECT Cepheids in M33B
table5.dat 32 57 DIRECT flux Cepheids in M33B
table6.dat 55 36014 Light curves of Cepheids in M33B
table7.dat 55 59 DIRECT other periodic variables in M33B
table8.dat 55 6088 Light curves of other periodic variables in M33B
table9.dat 48 391 DIRECT miscellaneous variables in M33B
table10.dat 55 39754 Light curves of miscellaneous variables in M33B
--------------------------------------------------------------------------------
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)
J/AJ/121/2032 : Direct variables in M33A field (Mochejska+, 2001)
http://cfa-www.harvard.edu/~kstanek/DIRECT/ : DIRECT Homepage
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Binary name (G1)
23- 29 F7.4 d Per Period of the system
30 A1 --- u_Per [:] Uncertainty flag on period
32- 36 F5.2 mag Vmag ? Maximum V band magnitude outside of eclipse
38- 42 F5.2 mag Bmag ? Maximum B band magnitude outside of eclipse
44- 47 F4.2 --- R1 Estimated primary component radius in units
of the orbital separation
49- 52 F4.2 --- R2 Estimated secondary component radius in units
of the orbital separation
54- 58 F5.2 deg Inc Estimated inclination angle of the orbit
60- 63 F4.2 --- Eccen Estimated eccentricity of the orbit
65 I1 --- Com [1]? Comments (2)
--------------------------------------------------------------------------------
Note (2): 1 = A variable identified by Macri et al. (2001, Cat. J/AJ/121/870)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Binary name (G1)
23- 29 F7.3 d Per Period of the system
30 A1 --- u_Per [:] Uncertainty flag on period
32- 36 F5.2 mag Vmag ?=99.99 The V band magnitude (2)
38- 42 F5.2 mag Bmag ?=99.99 The B band magnitude (2)
44- 47 F4.2 mag Vamp ? The V band amplitude
49- 52 F4.2 mag Bamp ? The B band amplitude
54- 55 A2 --- Com [12 EB] Comments (3)
--------------------------------------------------------------------------------
Note (2): The V and B band magnitude columns list the maximum magnitudes
for the eclipsing variables (EB) and flux-weighted average
magnitudes for the Cepheids and other variables.
Note (3): Comments as follows:
1 = A variable identified by Macri et al. (2001, Cat. J/AJ/121/870)
2 = A variable identified by Macri et al. (2001, Cat. J/AJ/121/861)
EB = Most likely an eclipsing binary
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Object name (G1)
23- 29 F7.4 d Per Period of the system
30 A1 --- u_Per [:] Uncertainty flag on period
32 I1 --- Com [1-2]? Comments (2)
--------------------------------------------------------------------------------
Note (2): Comments as follows:
1 = A variable identified by Macri et al. (2001, Cat. J/AJ/121/861
2 = A variable identified by Macri et al. (2001, Cat. J/AJ/121/870
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat table6.dat table8.dat table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Object name (G1)
23 A1 --- Ftr [BVbv] Filter passband (1)
25- 36 F12.4 d HJD Julian date of observation
38- 47 F10.3 --- Data Observed magnitude or differential flux (1)
49- 55 F7.3 --- e_Data Uncertainty in Data
--------------------------------------------------------------------------------
Note (1): The code indicates the filters:
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: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [D33]
4- 21 A18 --- D33 Variable name (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- 48 A4 --- Com [12 LP] Comment (1)
--------------------------------------------------------------------------------
Note (1): Comments as follows:
1 = A variable identified by Macri et al. (2001, Cat. J/AJ/121/870)
2 = A variable identified by Mochejska et al. (2001, J/AJ/121/2032)
LP = Most likely a periodic variable
--------------------------------------------------------------------------------
Global Notes:
Note (G1): The names are generated from the equatorial coordinates
of the object preceded by "D33" and "J", as
D33J RA(hhmmss.s) + Dec(ddmmss.s).
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 22-Jan-2002