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J/AJ/113/1711                   RR Lyrae in NGC 6171       (Clement+ 1997)

The structure of the light curves of the RR Lyrae variables in the Oosterhoff type I cluster NGC 6171 Clement C.M., Shelton I. <Astron. J. 113, 1711 (1997)> =1997AJ....113.1711C
ADC_Keywords: Stars, variable ; Magnitudes ; Clusters, globular Abstract: CCD observations have been used to derive precise light curves and Fourier parameters for sixteen RR Lyrae variables in the Oosterhoff type I globular cluster NGC 6171. It is found that, for the RRab stars, the Fourier phase differences φ21, φ31 and φ41 all correlate with period, but the amplitude ratios R21, R31, and R41 do not. For the RRc stars, R21, φ31, and φ41 correlate with period, but φ21, R31, and R41 do not. It is also found that a plot of R21 against φ21 is a useful tool for distinguishing between RRc and RRab stars, regardless of color or chemical composition. Simon's method that relates physical properties of RRc stars to the pulsation period and Fourier phase parameter φ31 has been used to determine the mass, luminosity, temperature and a helium parameter for the RRc stars. A comparison with the parameters determined from CCD observations of RRc stars in six other galactic globular clusters indicates that mean masses and mean luminosities increase and mean temperatures and helium abundances decrease with decreasing cluster metal abundance. The formulae of Jurcsik & Kovacs (1996, Cat. J/A+A/312/111) for relating Fourier parameters of RRab stars to [Fe/H] and luminosity have been tested and the results are reasonable. (c) 1997 American Astronomical Society. Description: The complete table caption from the printed paper follows: The Julian dates represent the time of mid-exposure. The magnitudes are on the standard V system. There are observations for 16 stars included here. They are variables: 4, 6, 7, 8, 9, 10, 12, 14, 15, 17, 18, 19, 20, 21, 23 and 24 (Cl* NGC 6171 DICK VNN, NN = 1 to 24, in Simbad database). Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 16 32 31.8 -13 03 13 NGC 6171 = M 107 = C 1629-129 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table8.dat 24 1987 Las Campanas observations for NGC 6171
Byte-by-byte Description of file: table8.dat
Bytes Format Units Label Explanations
1- 3 A3 --- Vname Variable name, as in Dickens, (1970ApJS...22..249D) Cl* NGC 677 DICK in Simbad 5- 16 F12.4 JD JD Julian date 18- 24 F7.4 mag Vmag V magnitude
Origin: AAS CD-ROM series, Volume 9, 1997 Lee Brotzman [ADS] 30-Oct-1997
(End) [CDS] 04-Feb-1998
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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