Abstract
It is noted that longward of 1 micron, the absolute calibration of the photometry needed for determining the energy distributions and color temperatures of cool stars has generally been based on theoretical energy distributions. A program now under way at Kitt Peak National Observatory, however, is providing direct measurements of absolute monochromatic fluxes in a set of standard stars at 13 wavelengths. Color temperatures from narrow-band measurements at 1.04 and 4.00 microns are especially well suited for very cool stars and are found to be in good agreement with the new effective temperature scale established from lunar occultation observations. Spectral features that can be measured by narrow-band photometry in the 1-4 micron region include bands of CO, CN, C2, OH, H2O, and SiO, and they offer the prospect of determining two-dimensional spectral classifications for late-type stars from infrared data alone.
