A stack of 40 scans obtained with ML Astro’s SHG 700 spectroheliograph.

A stack of 16 scans obtained with ML Astro’s SHG 700 spectroheliograph.

Using the ML Astro SHG 700 (third batch) spectroheliograph, on a 80/540 refractor, ASI 678MM camera, I recorded seven scans of the Sun, in the singly ionized iron line, Fe II 5018.45Å.

This is what I got after getting rid of the artefacts and amplifying a bit the already strong signal (way stronger than He I D3).

singly ionized Barium, Ba II at 6141.73Å

I scanned the Sun into a cube, containing the Ba II line at 6141.73Å which, like we’ve seen with ionized metals before, turn the active regions dark, instead of letting them shine against a darker photosphere. The atmosphere was remarkably calm on 2025-04-21, and further, the disks were anti-jagged by an experimental feature in JSolEx. (tovább…)