The effective temperature scale of giant stars (F0-K5) -: II.: Empirical calibration of Teff versus colours and [Fe/H]

We present calibrations of the effective temperatures of giant stars vel sus [Fe/H] and colours (U - V), (J - K), (I - K), (V - L'), (b - y) and (u - b). These calibrations are based on a large sample of field and globular cluster stars which roughly cover spectral types from F0 to K5. Their effective temperatures, scaled to direct T-eff determinations via reliable angular diameter measurements, were derived by applying the infrared flux method. The empirical relations have been fitted to polynomials of the form theta(eff) = P(colour, [Fe/H]) by using the least squares method. The precision of the fits ranges from 40 K for (V - K) to 170 K for (J - H). We tabulate intrinsic colours of giant stars in the ranges: 3500 K less than or equal to T-eff less than or equal to 8000 K; -3.0 less than or equal to [Fe/H] less than or equal to +0.5. We also present the calibration of BC(V) as a function of log(T-eff) and metallicity. Finally, we compare the resulting scale of temperatures with previous works.