J/AcA/57/249 VIc photometry of NGC 6755 stars (Ciechanowska+, 2007)
The Optical Gravitational Lensing Experiment. Variable stars in the field of
open cluster NGC 6755.
Ciechanowska A., Pietrzynski G., Kolaczkowski Z., Wyrzykowski L.,
Szewczyk O., Kubiak M., Udalski A., Szymanski M.K.
<Acta Astron., 57, 249-266 (2007)>
=2007AcA....57..249C 2007AcA....57..249C
ADC_Keywords: Clusters, open ; Stars, variable ; Photometry, VRI
Keywords: binaries: eclipsing - stars: oscillations -
open clusters and associations: individual: NGC 6755
Abstract:
We present the results from a search for variable stars in the field
of a young open cluster NGC 6755. Altogether seventy one variable
stars have been discovered. Thirty one of them are eclipsing systems.
This group contains ten EA, four EB and seventeen EW-type systems.
Photometric variability of four late type stars is most probably
caused by their chromospherical activity. Another seven detected
variable stars have light curves typical for pulsating stars from the
main instability strip. Four of them we tentatively classified as
gamma Dor, one as delta Sct and two as Population II Cepheid variable
stars, respectively. Star designated as V40 can be either another
population II Cepheid or an ellipsoidal binary system. The remaining
twenty eight variable stars found in the field of this open cluster
are most probably highly obscured background red giants (OSARG,
irregular). For all detected variable stars we provide their light
curves, preliminary classification, discussion on the possible cluster
membership, equatorial coordinates, finding charts and periods when
possible.
Description:
The presented data were collected from July 1997 to September 1999
during twenty seven nights in the course of the OGLE project at the
time, when the weather conditions were too poor to observe the very
dense main OGLE fields. All observations were made with 1.3-m Warsaw
telescope located at the Las Campanas Observatory, Chile which is
operated by the Carnegie Institution of Washington.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 50 16595 Positions and photometry of stars in the field
of NGC 6755
--------------------------------------------------------------------------------
See also:
ftp://sirius.astrouw.edu.pl/ogle/ : OGLE Home Page
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Seq Sequential number
8- 9 I2 h RAh Right ascension (J2000)
11- 12 I2 min RAm Right ascension (J2000)
14- 18 F5.2 s RAs Right ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 30 F4.1 arcsec DEs Declination (J2000)
32- 37 F6.3 mag Vmag Johnson V magnitude
40- 44 F5.3 mag V-Ic ?=- Johnson-Cousins V-Ic colour index
46- 50 I5 --- WEBDA Webda identification number
--------------------------------------------------------------------------------
History:
Copied at WEBDA, http://www.univie.ac.at/webda
(End) Patricia Vannier [CDS] 26-Jan-2010