O I 7772 ~ continuum, dark smudge at center-top-left
On 2026-04-05, I imaged the Sun across multiple wavelengths, and found that areas that are dark smudges in oxygen are:
- rather unassuming bright-ish plages in:
- Hα
- Ca II 8542
- Na I D2
- nothing obvious, small sunspot aside, in:
- continuum
- Fe I 7781
- dark in:
- (O I 7772, hence smudge)
- He I D3
- He I 10830
- H Paschen gamma
The images presented below are from scans recorded across several hours, each wavelength is the result of several scans stacked together. During acquisition, no major flares were reported. More about oxygen smudges here, here and here.
2026-04-05 O I 7772 divided by a continuum
2026-04-05 He I 10830, wavelength reconstruction, without subtracting a continuum
2026-04-05 H Paschen gamma, enhanced via continuum subtraction
2026-04-05 Paschen gamma, wavelength reconstruction, most artefacts removed
continuum chosen for paschen gamma, most artefacts removed
Paschen gamma against a continuum, most artefacts removed
continuum chosen for the oxygen
oxygen wavelength reconstruction
2026-04-05 Fe I 7781, the guide line for the oxygen
2026-04-05 Ca II 8542
2026-04-05 Na I D2
2026-04-05 He I D3, wavelength reconstruction
2026-04-05 He I D3, enhanced via continuum subtraction
2026-04-05 Hydrogen Alpha
Paschen gamma ~ continuum, artefacts
2026.04.05. paschen gamma wavelength, artefacts
continuum chosen for paschen gamma, artefacts
20260405084022 Gong Ha
1600(~)1700
20260405084238 AIA 1600
20260405084316 AIA 1700
20260405084041 SUVI 195
20260405084051 SUVI 284
20260405084248 AIA 0335
20260405084111 SUVI 304
20260405084242 AIA 131
20260405084252 sdo aia 0193 helioviewer
20260405084257 sdo aia 0211 helioviewer
20260405084309 sdo aia 0171 helioviewer
20260405084311 sdo aia 0094 helioviewer
20260405084315 sdo HMI Int helioviewer
