J/A+A/371/579 Empirical relations for cluster RR Lyrae (Kovacs+, 2001)
Empirical relations for cluster RR Lyrae stars revisited
Kovacs G., Walker A.R.
<Astron. Astrophys. 371, 579 (2001)>
=2001A&A...371..579K 2001A&A...371..579K
ADC_Keywords: Photometry ; Stars, horizontal branch ; Stars, variable ; Surveys
Keywords: stars: fundamental parameters - stars: distances - stars: variables -
stars: oscillations - stars: horizontal-branch -
globular clusters: general
Abstract:
Our former study on the empirical relations between the Fourier
parameters of the light curves of the fundamental mode RR Lyrae stars
and their basic stellar parameters has been extended to considerably
larger data sets. The most significant contribution to the absolute
magnitude MV comes from the period P and from the first Fourier
amplitude A1, but there are statistically significant contributions
also from additional higher order components, most importantly from
A3 and in a lesser degree from the Fourier phase phi51. When
different colors are combined in reddening-free quantities, we
obtain basically period-luminosity-color relations. From the standard
deviations of the various regressions, an upper limit can be obtained
on the overall inhomogeneity of the reddening in the individual
clusters. This yields σE(B-V)<0.012mag, which also implies an
average minimum observational error of σV>0.018mag.
Description:
This table (referred to as Table 2 in the above paper) consists of
4 subtables. They all contain (with the same format) the Fourier
decompositions of fundamental mode RR Lyrae stars and color index
averages (B-V and V-I, where I denotes the Kron-Cousins system).
All averages are computed as averages of the observed magnitudes.
Fourier decompositions refer to a *sine* series, given by the
following expression
V(t) = A0 + A1*sin[2*pi*(t-t0)*1*f0+phi1_]
+ A2*sin[2*pi*(t-t0)*2*f0+phi2] + ...
The epoch t0 is set to zero for all stars. The Fourier decompositions
are devoted to describe the form of the light curves and can not be used
for predicting light curves, because of the various truncations used in
the Julian Dates of the individual stars (e.g., t=HJD-2400000, etc).
The structure of the data for each variable is as follows:
Period Epoch A_0 N sigma Cluster Color-index A_1 phi_1 ... A_15 phi_15
Here *N* is the number of the data points used in the calculation
of the Fourier decomposition, *sigma* is the standard deviation
of the residuals of the fit, *Cluster* and *color index* are absent
in file *fieldv.dat*, *color index* is absent in *clusv.dat*. In
general, 15th order Fourier fit was used. Exact zero amplitudes and
phases show where the order was lower than this.
References to the data used in computing the Fourier decompositions
and color averages, can be found in the above paper and references
therein. Exceptions are variables from FW Lup down to the end of
the file *fieldv.dat*, where the data were taken from various
publications, including those of Lub (1977A&AS...29..345L 1977A&AS...29..345L),
Layden (1997, Cat. J/PASP/109/524) and
Schmidt & Seth (1996, Cat. J/AJ/112/2769).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 32 105 Field star positions (from Simbad)
table1.dat 108 21 Summary of the globular cluster data for RRab
stars
clusv.dat 300 387 *Fourier decompositions in V color for cluster
variables (table2, part 1/4)
clusbv.dat 300 179 Average observed B-V indices and Fourier
decompositions in V color for cluster variables
(table 2, part 2/4)
clusvi.dat 300 115 Average observed V-I indices and Fourier
decompositions in V color for cluster variables
(table 3, part 3/4)
fieldv.dat 300 105 Fourier decompositions in V color for Galactic
field variables (table 2, part 4/4)
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Note on clusv.dat: This file contains 387 variables, which is more than we used
in the paper, because by mistake, variables V7, V86 in M5 and V6, V8 in M92
were left out from the original data file. This has, however, no effect on
the results discussed in the paper.
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See also:
J/PASP/109/524 : Light Curves for 40 RR Lyraes (Layden 1997)
J/AJ/112/2769 : Behlen Observatory Survey. IV. (Schmidt+ 1996)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Star Field star name
10- 11 I2 h RAh Right ascension (J2000.0)
13- 14 I2 min RAm Right ascension (J2000.0)
16- 19 F4.1 s RAs Right ascension (J2000.0)
21 A1 --- DE- Declination sign (J2000.0)
22- 23 I2 deg DEd Declination (J2000.0)
25- 26 I2 arcmin DEm Declination (J2000.0)
28- 29 I2 arcsec DEs Declination (J2000.0)
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Cl Cluster number
4- 15 A12 --- Cluster Cluster name
17- 18 I2 h RAh Right ascension (J2000.0)
20- 21 I2 min RAm Right ascension (J2000.0)
23- 26 F4.1 s RAs ? Right ascension (J2000.0)
28 A1 --- DE- Declination sign (J2000.0)
29- 30 I2 deg DEd Declination (J2000.0)
32- 33 I2 arcmin DEm Declination (J2000.0)
35- 36 I2 arcsec DEs ? Declination (J2000.0)
38- 39 I2 --- NB ? Number of variables in B band
41- 42 I2 --- NV Number of variables in V band
44- 45 I2 --- NI ? Number of variables in I band
47- 65 A19 --- BibCode BibCode of the reference
67- 83 A17 --- Aut Reference author's name
85-108 A24 --- Star Nomenclature of the cluster stars name
in Simbad
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Byte-by-byte Description of file: clus*.dat field*.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Star Star name
13- 24 F12.10 d Period Period
26- 31 F6.4 d Epoch Epoch for phi=0 (various HJD truncations)
33- 38 F6.3 mag A0 Average V magnitude
40- 44 I5 --- N Number of data points
46- 52 F7.4 mag sigma Residual standard deviation
55- 56 I2 --- Cl ? Cluster number
58- 63 F6.4 mag Color ? Color code
66- 71 F6.4 mag A1 A1 Fourier amplitude
74- 79 F6.4 rad phi1 phi1 Fourier phase
82- 87 F6.4 mag A2 A2 Fourier amplitude
90- 95 F6.4 rad phi2 phi2 Fourier phase
98-103 F6.4 mag A3 A3 Fourier amplitude
106-111 F6.4 rad phi3 phi3 Fourier phase
114-119 F6.4 mag A4 A4 Fourier amplitude
122-127 F6.4 rad phi4 phi4 Fourier phase
130-135 F6.4 mag A5 A5 Fourier amplitude
137-142 F6.4 rad phi5 phi5 Fourier phase
145-150 F6.4 mag A6 A6 Fourier amplitude
153-158 F6.4 rad phi6 phi6 Fourier phase
161-166 F6.4 mag A7 A7 Fourier amplitude
169-174 F6.4 rad phi7 phi7 Fourier phase
177-182 F6.4 mag A8 A8 Fourier amplitude
185-190 F6.4 rad phi8 phi8 Fourier phase
193-198 F6.4 mag A9 A9 Fourier amplitude
201-206 F6.4 rad phi9 phi9 Fourier phase
209-214 F6.4 mag A10 A10 Fourier amplitude
216-221 F6.4 rad phi10 phi10 Fourier phase
224-229 F6.4 mag A11 A11 Fourier amplitude
232-237 F6.4 rad phi11 phi11 Fourier phase
240-245 F6.4 mag A12 A12 Fourier amplitude
248-253 F6.4 rad phi12 phi12 Fourier phase
256-261 F6.4 mag A13 A13 Fourier amplitude
264-269 F6.4 rad phi13 phi13 Fourier phase
272-277 F6.4 mag A14 A14 Fourier amplitude
280-285 F6.4 rad phi14 phi14 Fourier phase
288-293 F6.4 mag A15 A15 Fourier amplitude
295-300 F6.4 rad phi15 phi15 Fourier phase
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Acknowledgements: Geza Kovacs
History:
Some modifications in the star nomenclature of table1 on 26-Mar-2002
(End) Geza Kovacs [Konkoly Observatory], Patricia Bauer [CDS] 22-May-2001