The Barium stars have attracted recently my attention because they had remained somewhat of an astrophysical enigma for several decades: They are Population I G-K giants that have enhanced abundances of carbon (G band of CH molecules) and s-process elements (notably lines of Ba II and Sr II) as prominent anomalous features. Today it is clear that the origin of these anomalous abundances in barium stars can be explained by the discovery that they are likely all members of binary systems. A mass exchange has taken place and is responsible for the detected anomalous abundances.
I have tried to record a spectrum of the Barium star HD 223617 using the SA 100. Ba and Sr lines could not be detected due to the low resolution. However, a weak CH band at 4380 A and the weak G band at 4300 A could tentatively be detected. As positive control for these CH bands I have recored the carbon CH star HD 5223, as negative control the carbon star Z Psc (showing mainly C2 bands).
Reference spectra of these stars are shown below:
I haven't found so far low resolution spectra of Barium stars in this forum or in the BAA-spectroscopy database and it would be interesting to see some ALPY or SA-200 spectra for comparison.