25/2/2022: Hydrogen lines.

[Icosahedron]

A sunny morning at last...

[Johan L]

Nice set of images  

[Pete Presland]

lovely set of images

[Merlin66]

Nice collection!

which target wavelengths were you using?

[vineyard]

Beautiful - are the last two double-stacked?

Btw is there something slightly odd about the shape of the solar disc in the SW quadrant (it doesn't seem circular (especially the higher up images)?  This is not a criticism, more just to check whether my eyes are working or if I need to go to the optician!

[Icosahedron]

Thanks all for the kind comments.

@Merlin66:
The wavelengths are 410.17 nm (H-delta), 434.05 nm (H-gamma) and 486.13 nm (H-beta).

@vineyard:
The images were captured with a spectroheliograph using the drift method. It takes about two minutes to perform a capture and as it was windy, movement of the instrument affected the shape. The limb of the Sun was also affected but the software routine that I use to address the effect of atmospheric seeing on the limb restored it. Still need to do a routine to constrain the shape to a disc.

[Icosahedron]

I've added a processing routine to constrain the shape to a disc in a lossless manner, only geometry is affected. The sharply defined limb at 2 and 8 o'clock is due to it passing through the centre of the telescope objective during the capture sequence. The limb at 5 o'clock confirms a spectroscope/camera alignment problem that I've noted before while using a test setup.

[Icosahedron]

What I meant to say in my previous post is that the Sun crossed the optical axis of the telescope in a line from the 2 o'clock to 8 o'clock position. Anyway, here's one more, H-beta reprocessed: