H-alpha and near-infrared spectra of late-type Be and A F-type shell stars

Profiles of H-alpha and the near-infrared lines of O I and Ca II in the spectra of a number of bright Be stars of later type, and A - F shell stars were obtained with a CCD detector at the Kitt Peak coude feed telescope in November 1984. The lines studied show sharp absorption cores in the shell stars, as expected, and there appears to be a smooth transition from the late-type Be stars to the A-type shell stars. However, the H-alpha line changes from emission to absorption rather abruptly from the late Be stars to the early A-type shell stars.