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Paper: The Distance to the Large Magellanic Cloud from First Overtone RR Lyrae Variables
Volume: 310, Variable Stars in the Local Group (IAU Colloquium 193)
Page: 180
Authors: Muzzin, A.V.; Clement, C.M.; Alves, D.R.; MACHO Collaboration, The
Abstract: Fourier coefficients have been derived for the V and R light curves of 330 bona fide RR Lyrae first-overtone (RR1) pulsators in 16 MACHO fields near the bar of the LMC. We use the Fourier phase parameter ø31 and the log P values to select a subsample of these stars which are similar to the RR1s in the Galactic globular cluster M5. Assuming that the M5-like stars in the LMC have absolute magnitudes comparable to the HB stars in M5, we use independent studies to derive their mean absolute V magnitude and compute a nisual distance mudulus of μLMC = 18.43 ±0.06 (statistical) ±0.16 (systematic). By selecting stars on the basis of their light curve parameters, we are able to derive a distance modulus that does not depend on the somewhat poorly determined Mv − [Fe/H] relation for RR Lyr stars.
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