Carbon stars in the Small Magellanic Cloud. I. The survey technique and results for two fields.

A survey for carbon stars in the Small Magellanic Cloud is being carried out with the GRISM technique. Observations are performed in the green spectral region, and the GRISM spectra are analyzed photometrically. This results in a magnitude, a color equivalent, and a carbon-abundance index. In the present paper the technique is applied to 2 of the 13 fields which together cover the main body of the Small Cloud. The derived quantities are compared with the corresponding quantities measured in IDS spectra of a few stars. Comparisons with previous results derived in other spectral regions are also presented. With the aid of the latter bolometric magnitudes for the present sample are determined. The existence of a number of natural groups of carbon stars is pointed out.