2004A&A...424..199B

New empirical calibrations of the Red Giant Branch Tip in the I, J, H and K bands based on two fundamental pillars, namely ω Centauri and 47 Tucanae, have been obtained by using a large optical and near infrared photometric database. Our best estimates give M_I^TRGB=-4.05±0.12, M_J^TRGB=-5.20±0.16, M_H^TRGB=-5.94±0.18 and M_K^TRGB=-6.04±0.16 at [M/H]≃-1.5 (ω Cen) and M_I^TRGB=-3.91±0.13, M_J^TRGB=-5.47±0.25, M_H^TRGB=-6.35±0.30 and M_K^TRGB=-6.56±0.20 at [M/H]≃-0.6 (47 Tuc). With these new empirical calibrations we also provide robust relations of the TRGB magnitude in the I, J, H, and K bands as a function of the global metallicity. It has also been shown that our calibrations self-consistently provide a distance modulus of the Large Magellanic Cloud in good agreement with the standard value ((m-M)₀≃18.50)).