Scanner photometry of weak TiO bands near 1 micron in cool M stars.

Continuous scans in the region 966010,400 A reveal that overlapping TiO bands depress the continua of cool M stars significantly, shortward of 10,000 A, and are present, though weaker, from 10,000 to 10,300 A. The bands become visible at about spectral type M3 and increase in strength throughout the M sequence; thus, they are potentially useful as spectral classification criteria for late M stars. Band strengths of TiO and VO, measured in the 1- region by scanner observations at discrete wavelengths, are found to be correlated over the spectral range M7-M9.8. Subject headings: late-type stars - molecules - spectra, infrared - spectral classification