Absolute magnitudes and zero-points

The absolute magnitudes are computed from the absolute luminosity given in the tracks and the bolometric corrections computed from stellar atmosphere models. For all the photometric systems described in the following sections, we give the absolute magnitude, , expressed in the Johnson band. Absolute magnitudes in the other passbands can then be derived from the colour indices provided in the files. Our adopted bolometric correction scale is that described in Lejeune et al. (1998), defined in such a way to fit the empirical scale of Flower (1996) instead of using the unique calibration point of the Sun. Note that with this definition, we find for the solar model of Kurucz (1992), a value slightly different of that usually quoted for the Sun.

The zero-points of the colours are defined from the Vega model spectrum of Kurucz (1992); for the (UBV)$_J$(RI)$_C$ JHKLL$^\prime$M, the CMTT, and the HST-WFPC2 photometric systems, the computed colours for this model are set to zero, while for the Geneva system these values are adjusted on the observed photometry of Vega, , , , , , and (Rufener 1976), and