Spectrophotometry Characteristics of Barium Stars

Abstract

Image-tube spectra with dispersions of 43A/mm at H-gamma and intermediate-band photometry on the DDO system were obtained for about 300 barium stars. These stars with enhanced Ba II at 4554A are otherwise generality similar to late-type giant stars. The majority of them were identified in an objective-prism survey by MacConnell et al. (1972). They listed 150 “certain” and 90 “marginal” Ba stars but made no further estimates of barium intensity. A more complete spectrophotometric study was carried out by Lu et al. (1983, hereafter referred to as Paper I). For 221 stars whose Ba intensities are one or more on Warner’s (1965) intensity scheme, the study has shown that the intensity of the line at 4554A correlates with both spectral type and the DDO color index C(4l–42). In addition to the cyanogen band, this index measures the intensity of a broad depression feature appearing in one barium star according to Bond and Neff (1969) and found to exist in other barium stars as well by Lu and Sawyer (1979).