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J/A+A/363/L1       The distance modulus of the LMC        (Kovacs, 2000)

The distance modulus of the Large Magellanic Cloud based on double-mode RR Lyrae stars. Kovacs G. <Astron. Astrophys. 363, L1 (2000)> =2000A&A...363L...1K
ADC_Keywords: Galaxies, nearby ; Photometry ; Stars, distances ; Stars, horizontal branch ; Stars, variable ; Surveys Keywords: stars: fundamental parameters - stars: distances - stars: variables - stars: oscillations - stars: horizontal-branch - globular clusters: general - galaxies: Magellanic Clouds Abstract: We use double-mode RR Lyrae (RRd) stars from the MACHO variable star database of the Large Magellanic Cloud (LMC) to estimate its distance, by utilizing photometric data, linear pulsation and stellar atmosphere models. If we set E(B-V)=0.11 and [M/H]=-1.5 for LMC, we get M-m=18.52mag. The fact that the distance moduli obtained in this and in our former studies of cluster RRd and Small Magellanic Cloud beat Cepheids agree so well, implies that the only serious source of error is the zero point of the temperature scale, which should not have larger than ±0.10mag effect on the distance modulus. Description: This table provides periods, intensity averaged V magnitudes and magnitude averaged V-Rc (Johnson V & Kron-Cousins R) colors of the MACHO LMC double-mode RR Lyrae variables employed in the above paper. For the calculation of the averages, an iterative 3-sigma condition was used to omit outliers. Further references (coordinates, amplitude ratios, etc.) to these variables can be found in Alcock et al. (1997ApJ...482...89A) and in Alcock et al. (2000, Cat. J/ApJ/542/257). Trasformation to the standard system has been performed in accordance with Alcock et al. (1999PASP..111.1539A). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file lmcrrd.dat 85 181 Double mode RR Lyr stars in LMC
See also: J/AJ/114/326 : MACHO Variables V. (Alcock+ 1997) J/ApJ/542/257 : MACHO Variables IX. (Alcock+ 2000) : MACHO home page Byte-by-byte Description of file: lmcrrd.dat
Bytes Format Units Label Explanations
1- 13 A13 --- MACHO MACHO identifier (FFF.NNNNN.NNNN) 18- 25 F8.5 d P0 Period 29- 34 F6.4 --- P1/P0 Period ratio 39- 44 F6.3 mag Vmag Average V magnitude 50- 55 F6.3 mag V-R Average V-Rc color index 61- 64 I4 --- Npoints Number of data points 66- 67 I2 h RAh ? Right ascension (J2000) (1) 69- 70 I2 min RAm ? Right ascension (J2000) (1) 72- 75 F4.1 s RAs ? Right ascension (J2000) (1) 77 A1 --- DE- ? Declination sign (J2000) (1) 78- 79 I2 deg DEd ? Declination (J2000) (1) 81- 82 I2 arcmin DEm ? Declination (J2000) (1) 84- 85 I2 arcsec DEs ? Declination (J2000) (1)
Note (1): Positions added at CDS from Alcock et al., 1997ApJ...482...89A and 2000, Cat. J/ApJ/542/257.
Acknowledgements: Geza Kovacs
(End) Geza Kovacs [Konkoly Observatory], Patricia Bauer [CDS] 07-Dec-2000
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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