J/other/RMxAA/44.365 New variable stars in NGC 6366 (Arellano Ferro+, 2008)
A new search for variable stars in the globular cluster NGC 6366.
Arellano Ferro A., Giridhar S., Rojas Lopez V., Figuera R.,
Bramich D.M., Rosenzweig P.
<Rev. Mex. Astron. Astrofis., 44, 365 (2008)>
=2008RMxAA..44..365A 2008RMxAA..44..365A
ADC_Keywords: Clusters, globular ; Stars, variable ; Photometry, CCD
Keywords: globular clusters: NGC 6366 - variable stars: RR Lyrae, SX Phe -
eclipsing binaries
Abstract:
New CCD photometry of NGC 6366 has lead to the discovery of some
variable stars. Two possible Anomalous Cepheids (or Pop II Cepheids),
three long period variables, one SX Phe and one eclipsing binary have
been found. Also a list of 10 candidate variables is reported. The
light curve of the RRab star, V1, has been decomposed into its Fourier
harmonics, and the Fourier parameters were used to estimate the star's
metallicity and distance; [Fe/H]=-0.87±0.14 and d=3.2±0.1kpc. It
is argued that V1 may not be a member of the cluster but rather a more
distant object. If this is so, an upper limit for the distance to the
cluster of 2.8±0.1kpc can be estimated. The P-L relationship
for SX Phe stars and the identified modes in the newly discovered SX
Phe variable, V6, allow yet another independent determination of the
distance to the cluster of d=2.7±0.1kpc. The MV-[Fe/H]
relationship for RR Lyrae stars is addressed and the case of V1 is
discussed.
Objects:
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RA (2000) DE Designation(s)
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17 27 44.3 -05 04 36 NGC 6366 = C 1725-050
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
objects.dat 62 18 List of objects
rrlyrv1v.dat 26 61 Standard V magnitudes of RR Lyrae star V1
varr.dat 26 365 Instrumental r magnitudes of new variable stars
varv.dat 26 359 Standard V magnitudes of new variable stars
candr.dat 26 669 Instrumental r magnitudes of candidate to
variable stars
candv.dat 26 671 Standard V magnitudes of candidate to
variable stars
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Byte-by-byte Description of file: objects.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Table Variable (table1) or Candidate (table2)
11- 13 A3 --- Star Star name (V for Vriable, C for Candidate)
16- 27 A12 --- VFile File with the V light curve
29- 37 A9 --- rFile File with the r light curve
41- 45 F5.2 mag Vmag Mean V magnitude
47- 52 A6 --- Type Variability type
54- 62 F9.7 d Per ? Period
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Byte-by-byte Description of file: *.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Star Variable (V1 to V8) or candidate (C1 to C11)
number identification
5- 16 F12.4 d HJD Heliocentric Julian Date
19- 24 F6.3 mag mag Instrumental r or standard V magnitude
26 A1 --- Band [Vr] Photometric band for magnitude
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Acknowledgements:
A. Arellano Ferro, armando(at)astroscu.unam.mx
(End) A. Arellano Ferro [UNAM, Mexico], Patricia Vannier [CDS] 04-Sep-2008