J/other/RMxAA/40.209 VR light curves of 15 RR Lyrae in NGC 4147 (Arellano+ 2004)
CCD photometry of the RR Lyrae stars in NGC 4147.
Arellano Ferro A., Arevalo M.J., Lazaro C., Rey M., Bramich D.M.,
Giridhar S.
<Rev. Mex. Astron. Astrofis., 40, 209-221 (2004)>
=2004RMxAA..40..209A 2004RMxAA..40..209A
ADC_Keywords: Clusters, globular ; Stars, variable ; Photometry, CCD
Keywords: globular clusters: NGC 4147 - stars: variables: RR Lyrae
Abstract:
We report the results of CCD V and R photometry of the RR Lyrae stars
known in NGC 4147. The periodicities of most variables are revised and
new ephemerides are calculated. The Blazhko effect has been detected
in V2 and V6. Three previously reported variables; V5, V9, and V15 are
found to be non-variable. A new variable V18 was discovered with a
period of 0.49205-days and an amplitude of 0.15mag. Using the
approach of Fourier decomposition of the light curves, the physical
parameters of the RRab and RRc variables were estimated. The cluster
is of the Oosterhoff type I. With the newly values [Fe/H]=-1.22±0.31
and 16.8±1.3kpc, the cluster fits very well into the Oosterhoff
type-metallicity and metallicity-temperature sequence found in
globular clusters. A comparison with ZAHB models indicates that the
RRab stars have not yet evolved off the horizontal branch, a result
consistent with the mean period of the RRab variables and with the
metallicity of the cluster derived in this work.
Description:
Time-series V and R photometry for the variable stars in NGC4147.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 51 18 Update of periods, epochs, and amplitudes for
the RR Lyrae stars in NGC 4147
varphot.dat 24 4336 CCD time-series V and R photometry of
15 variables in NGC 4147
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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- 3 A3 --- Vno Variable name (VNN), Cl* NGC 4147 SAW VNN in Simbad
5- 6 A2 --- Type [ab c] Type of RR Lyrae variable
8- 15 F8.6 d OPer ? Old period
16 A1 --- u_OPer Uncertainty flag on OPer
17- 19 A3 --- n_OPer [pnv] "pnv" for "probably not variable"
21- 27 F7.5 d Per ? New Period
28- 29 A2 --- n_Per [nv] "nv" for "not variable"
31- 39 F9.3 d T0 ? Epoch of maximum light (JD-2400000)
41- 44 F4.2 mag Vamp ? Amplitude in V band
45 A1 --- n_Vamp [a] Blazhko effect (1)
47- 50 F4.2 mag Ramp ? Amplitude in R band
51 A1 --- n_Ramp [a] Blazhko effect (1)
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Note (1): a: Maximum amplitude but there is evidence of Blazhko effect.
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Byte-by-byte Description of file: varphot.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Vno Variable name (VNN)
5 A1 --- Filter [VR] Observation filter
7- 17 F11.3 d HJD Heliocentric Julian date at mid-exposure
19- 24 F6.3 mag magst Standard magnitude in Filter
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Acknowledgements:
Daniel Bramich, dbramich(at)eso.org
(End) Daniel Bramich [ESO, Germany], Patricia Vannier [CDS] 28-Jan-2013