Abstract
Preliminary results on a procedure intended to characterize the low-dispersion spectra of M and carbon stars using image-processing techniques is presented. Objective-prism plates were obtained with Schmidt-type telescopes at CTIO and CIDA, each equipped with a four degree prism. Several fields in the Milky Way were photographed using Kodak W-N emulsion (hypersensitized in AgNO3) and a RG-695 Schott filter. This procedure yielded spectra in the range 6800-8800A , with a dispersion of 1700 A/mm (CIDA). Density tracings from the spectra of M and C stars, on the plates, were obtained using the PDS 1010 microdensitorneter, at the IBM Scientific Center, in Caracas, and the Joyce-Loebl microdensitorneter at the Universidad de Los Andes, Merida. The IBM interactive image-processing system HACIENDA was used to study the resulting images. Contrast-enhancing and color-coding routines were applied to the spectral images. They were characterized applying morphological criteria based on pixel-density distribution plots and the definition of virtual color indices. Practical procedures for obtaining spectroscopic, photometric asd astrometric data from Schmidt plates using automated methods are discussed.
