J/AJ/133/2696 BVRI light curves of Westerlund 1 stars (Bonanos, 2007)
Variability of young massive stars in the galactic super star cluster
Westerlund 1.
Bonanos A.Z.
<Astron. J., 133, 2696-2708 (2007)>
=2007AJ....133.2696B 2007AJ....133.2696B
ADC_Keywords: Clusters, open ; Binaries, eclipsing ; Photometry, UBVRI
Keywords: binaries: eclipsing -
open clusters and associations: individual (Westerlund 1) -
stars: variables: other - stars: Wolf-Rayet
Abstract:
This paper presents the first optical variability study of the
Westerlund 1 super star cluster in search of massive eclipsing binary
systems. A total of 129 new variable stars have been identified,
including the discovery of 4 eclipsing binaries that are cluster
members, 1 additional candidate, 8 field binaries, 19 field delta
Scuti stars, 3 field W UMa eclipsing binaries, 13 other periodic
variables, and 81 long-period or nonperiodic variables. These include
the known luminous blue variable, the B[e] star, 11 Wolf-Rayet stars,
several supergiants, and other reddened stars that are likely members
of Westerlund 1. The bright X-ray source corresponding to the
Wolf-Rayet star WR 77o (B) is found to be a 3.51 day eclipsing binary.
The discovery of a reddened detached eclipsing binary system implies
the first identification of main-sequence stars in Westerlund 1.
Description:
Photometry of Westerlund 1 was obtained with the Direct CCD on the 1m
Swope telescope at Las Campanas Observatory, Chile. The camera uses a
2048x3150 SITe CCD with a pixel size of 15um/pix and a pixel scale of
0.435"/pix. A 1200x1200 section of the CCD corresponding to 8.7' on
the side was read out, centered at RA=16:47:03.8, DE=-45:50:41
(J2000.0). The observations were made on 17 nights between UT 2006
June 15 and July 25, typically in IRVB sequences.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 99 129 Westerlund 1 Variable Star Catalog
table3.dat 54 53917 Light Curves of Variables in Westerlund 1
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See also:
J/A+AS/127/423 : VI photometry of Westerlund 1 and 2 (Piatti+ 1998)
J/A+A/477/147 : X-ray sources in Westerlund 1 (Clark+, 2008)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Catalog name (1)
14- 32 A19 --- [B2007] Name (JHHMMSS.ss+DDMMSS.S)
34- 39 F6.3 mag Bmag ? Intensity-averaged B band magnitude
41- 46 F6.3 mag Vmag ? Intensity-averaged V band magnitude
48- 53 F6.3 mag Rmag ? Intensity-averaged R band magnitude
55- 60 F6.3 mag Imag ? Intensity-averaged I band magnitude
62- 77 A16 --- SpType Spectral type (2)
79- 92 A14 --- Class Light curve classification
94- 99 F6.4 d Per ? Period
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Note (1): Given by Westerlund (1987A&AS...70..311W 1987A&AS...70..311W), if available, or the
revised identification given by Clark et al. (2005A&A...434..949C 2005A&A...434..949C).
NN = Cl* Westerlund 1 W NNN in Simbad
WR77aa(A) = WR 77aa = Cl* Westerlund 1 CN A in Simbad.
Note (2): The spectral classification when available from Clark et al.
(2005A&A...434..949C 2005A&A...434..949C) and for the WR variables from Crowther et al.
(2006MNRAS.372.1407C 2006MNRAS.372.1407C), the light curve classification, and period when
applicable. Variables with X-ray detections by Skinner et al.
(2006ApJ...639L..35S 2006ApJ...639L..35S) have an "X" following their WR classification.
Note, that the catalog includes photometry for some stars that are
missing from Clark et al. (2005A&A...434..949C 2005A&A...434..949C) due to the gap between
their two CCDs and their smaller field of view.
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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- 19 A19 --- [B2007] Name (JHHMMSS.ss+DDMMSS.s)
21 A1 --- Filter [BVRIbvr] Filter passband (1)
23- 35 F13.5 d HJD Julian date of observation
37- 46 F10.3 --- Data Observed magnitude or differential flux
48- 54 F7.3 --- e_Data Uncertainty in Data
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Note (1): Filters as follows:
B = Indicates Data is the Johnson B passband magnitude
V = Indicates Data is the Johnson V passband magnitude
R = Indicates Data is the Johnson R passband magnitude
I = Indicates Data is the Johnson I passband magnitude
b = Indicates Data is the Johnson B passband differential flux
v = Indicates Data is the Johnson V passband differential flux
r = Indicates Data is the Johnson R passband differential flux
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 27-May-2009