Lithium in C and CS Stars
Brian D. Warner, Charles A. Dean · Publications of the Astronomical Society of the Pacific · 1970
To increase the number of accurate spectral classifications and measured radial velocities for carbon and related stars, we are obtaining spectra at 50 and 100 Â/mm with the Meinel spectrograph and Carnegie S20 image tube at the McDonald Observatory.This system is highly suitable for the study of red stars; working at 100 Â/mm we use a grating blazed at 4250 Â and obtain spectra of nearly uniform density over the range 4000-7500 Â.At 50 Â/mm we achieve good densities over the range 5700-7200 Â.Nearly all of the stars that we have observed so far are selected from red and infrared objective-prism surveys made at the Dearborn, Warner and Swasey, and Tonantzintla Observatories.We are concentrating on C and CS