This could be of interest to anyone vaguely interested in spectroscopy who doesn't want to spend a lot of money. It's a 27mm eyepiece (Kellner I think) with a diffraction grating screwed in. Basically you aim your scope at a reasonably bright star, orient the grating appropriately and turn the telescope drive off briefly. A quite respectable spectrum then gets smeared out across the field of view. I've attached a sample spectrum of Altair. This has been gathering dust in my collection for many years and I just wondered if anyone might be interested in it. $25 plus shipping costs.
Cheers
Steve
Last edited by Stevec35; 30-10-2020 at 07:34 AM.
Reason: Status
