SIMBAD references

New photometry of RRab and RRc stars in ω Centauri is used to calibrate their absolute magnitudes M_Vas a function of (a) metallicity and (b) the Fourier parameters of light curves in the V band. The zero point of both calibrations relies on the distance modulus to the cluster derived earlier by the Cluster AgeS Experiment (CASE) project based on observations of the detached eclipsing binary OGLE GC17. For RRab variables, we obtained a relation of M_V(0.26±0.08)[ Fe/H ] + (0.91±0.13). A dereddened distance modulus to the Large Magellanic Cloud (LMC) based on that formula is µ₀ 18.56±0.14 mag. The second calibration of M_V, which is based on Fourier coefficients of decomposed light curves, results in the LMC distance of µ₀ 18.51±0.07 mag.