SIMBAD references

Calibrated synthetic DDO colours computed from Kurucz (1993, CD-Rom 13) atmosphere models and fluxes are presented. The transformation equations to make synthetic colours consistent with the observational system are derived by using a set of calibration stars for which atmosphere parameters are known from high resolution spectroscopy. The synthetic C(45-48) versus C(42-45) diagram is compared with observational sequences of Population I giants and dwarfs and a good agreement is obtained. The metallicity effect in the synthetic diagram is discussed. The obtained results lead to the conclusion that synthetic calibrated DDO colours are valuable tools for analysing Population I and II late-type stars and for computing integrated colours of globular clusters and galaxies.