Towards the absolute planes: a new calibration of the bolometric corrections and temperature scales for Population II giants

We present new determinations of bolometric corrections and effective temperature scales as a function of infrared optical colours, using a large data base of photometric observations of about 6500 Population II giants in Galactic globular clusters (GGCs), covering a wide range in metallicity (−2.0 < [Fe/H] < 0.0).   New relations for BC _K versus ( V  −  K ) , ( J  −  K ) and BC _V versus ( B  −  V ), ( V  −  I ), ( V  −  J ), and new calibrations for T _eff, using both an empirical relation and model atmospheres, are provided.   Moreover, an empirical relation to derive the R parameter of the infrared flux method as a function of the stellar temperature is also presented.