TEMPERATURES FOR A0-K0 SUPERGIANTS FROM 13-COLOR PHOTOMETRY

Observations on the 13-color photometric system are reported for 71 A0 -K0 supergiant stars brighter than V = 6.0. Three independent methods to determine the effective temperatures for A0-K0 supergiants from the ir 13C photometry are discussed: (1) Calibrations between T-eff and re ddening-free indices are developed; temperatures were collected from t he literature for the calibration stars, and most of them were spectro scopically determined. (2) An empirical correlation between intrinsic colors in the 13C system and T-eff has been derived. (3) The unreddene d colors are compared with synthetic colors calculated by Kurucz (1989 , personal communication); this leads to simultaneous estimates for T- eff and log g. The estimated uncertainties in T-eff by the three metho ds are comparable and are approximately +/- 200-300 K.