The He I 5015 prominence, probably the least significant bit in the data
Using the usual setup, an ML Astro SHG 700 on a 80/540 refractor and a cooled IMX 678 camera, with an in-cone interference filter as an ERF, letting through the oxygen line, and coincidentally, the Fe II 5018.45Å and also the He I 5015.7Å lines, I managed, for the first time, to dig out a bright-ish prom in the green (turquoise-something) Helium line.
This could well be among the first, if not the very first amateur observation of this line.
See
https://physics.nist.gov/PhysRefData/Handbook/Tables/heliumtable2.htm
Processed using JSolEx.
Ha, for reference
the recorded spectrum vs the reference, 5018 marked with lime, and the expected position of the Helium
A continuum, 19px towards the blue, from the iron line(s) at 5018. The He is at around 26px
A continuum at +15 pixels offset
the Fe II 5018 disk
Fe II prominence, ImageMath applied, continuum subtraction etc
Fe II prominence, further enhanced
Fe II disk, enhanced
Fe II, reflecting the recorded intensity
Fe II signal on the disk
looking for the He I 5015.7 signal, continuum subtraction
He signal, pushed further
the difference of the logarithms of the He I 5015 line and the chosen continuum
