The Ring nebula has an "iron bar"

[Dan Smiley]

I found this interesting, apparently never before seen

https://skyandtelescope.org/astronomy-news/the-ring-nebula-has-an-iron-bar/

According to the article the instrument used was WEAVE a fiber-fed multi-object spectrograph on the William Herschel telescope in La Palma.  "Ionized iron atoms — that is, atoms with their outermost electrons stripped off — glow at 422.7 nanometers, but the Ring’s emission at that wavelenth is faint. 'You would need a dedicated narrow-band filter to isolate it,” [Roger Wesson] adds. 'It is not a commonly observed emission line, so I doubt any such filter exists at any observatory.'"

hmm, anyone know how to make a 422.7 filter? put it on a big scope, maybe night vision??