Hi,
That’s a terrific piece of work. A dramatic demonstration of stellar spectroscopy.
You mention the long exposures, working at mag +13 what length were they? I’ve built several fairly crude spectroscopes over the years but I was drooling over the multitude of very neat commercial devices that were on show at the Astrofest! I’m tempted to put one on my C9.25….
cheers,
Bill.