1994A&AS..107..365A

The results of a long term programme of broad band JHK photometry, for a sample of 360 late type stars, made at the Observatorio del Teide (Tenerife, Spain) are presented. Transformations between these magnitudes and those of several currently used systems (CIT (Elias et al. 1982 and Carney 1983), Johnson (Johnson 1966, and Lee 1970), and ESO (Bouchet et al. 1991)) are proposed. A comparison to the narrow-band system of Selby et al. (1988) has been made, in order to check the accuracy of the photometric system. A mean internal accuracy better than 0.02mag in the three bands can be inferred from the comparison to the large number of stars in common with Carney (1983), and from the dispersion of the multiple measured stars. The list of standards, the filter passbands and effective wavelengths, together with correlations between the extinction coefficients, ultimately characterize the photometric IR system of the Observatorio del Teide (TCS). Data of comparable quality previously published have been added in order to complete the sample. This way the final sample consists of 550 stars. From the analysis of optical and IR colour:colour diagrams, we may deduce that the range F0-K0 is properly sampled for 0.1>[Fe/H]>-3.0. In the range K0-M4, no reliable photometric estimates of metallicity can be assigned, and only a small number of stars have spectroscopic determination of the metallicity. Nevertheless, after kinematical considerations, the stars in this spectral range are also expected to sample the galactic populations of dwarfs. The metallicity effects on the IR and optical colour:colour diagrams are briefly discussed.