With a rather unusual setup, the SolEx coupled with the IMX 571 wielding Altair Astro 26C camera, I observed a bright solar flare at 2025-09-28 08:43Z (a longer time series actually) at to my surprise, the helium line also lit up. This is not a typical nor a recommended setup of the SolEx. I sacrificed spatial (either way, bad seeing) and spectral (…) resolution for bit depth.

With the Helium image, I cheated a bit: the perpetually changing thin clouds resulted in the helium wavelength’s disk center getting saturated from time to time, so data’s been taken from non-saturated takes, to fill that gap.

He I 5015, continuum-subtracted

Fe II 5018, CLAHE-enhanced signal

spectra, before and during

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.

(tovább…)

I stacked together some decent scans into this frame of hydrogen gamma. ML Astro SHG 700, with a 80/540 refractor, in-cone ERF, Ersatz-Obsi.