Here is a high resolution spectrum that I took of chi Cygni on 10th September, “zooming” in on the hydrogen alpha emission line. The spectrum shows wonderful complexity at this level of detail, though I can’t say that I’m able to interpret most of it. I suspect a lot is due to molecular absorption bands.
I have tried to identify the absorption line at about 6572 Angstroms but to no avail. Neutral Yttrium and singly ionised calcium have lines in that region, but they may not be the cause of this absorption line.
Best wishes,
Andy