On 2026-06-24, I observed the flare that occurred and peaked at around 0710Z, in the neutral carbon lines C I 9095 and C I 9112. Both darken subtly when the flare is present, just like oxygen does. But unlike with oxygen, which has an obvious chromosphere, I failed so far to identify anything meaningful for these carbon lines.

Also much like the oxygen, sunspots show excess light, while plages show a deficit, the disk being overall rather dull in comparison to neighboring continuum lines.

An interesting factor when processing these pictures is that the reference lines land on tellurics, and hence the solar lines doppler visibly as we scan from solar west to east.

The flare is at the big „bright” sunspot, bottom left.