CaK and very large filament 05Dec21

[Merlin66]

Testing some filters....
On CWL (3933.7A) the plage and chromospheric network shows well and also the very large filament down south.
Moving towards the violet (K2v) and the filament is still visible.
When moved to the red side (K2r) the filaments disappear and the brightness of the active areas is enhanced .

[Martin_S]

Great work Ken, your SHG really brings out the detail.

Is it possible to use additional filters with the Lunt Cak module to enhance the violet side of the spectrum?.

Martin

[Merlin66]

Martin,
The Lunt CaK module is quoted as 2.2A bandwidth.
If you stacked two ($$$$) the best you'd get would be around 1.4A.
That's not enough resolution to pick out the K2 features which lie only 0.2A either side of the core and are only 0.1 to 0.15A wide.
The SHG is the way to go!!

[Martin_S]

Thanks Ken, hopefully someone will market a SHG kit in the not too distant future.

Martin

[Merlin66]

Martin,
The nearest thing at the moment is Buil's Sol'Ex 3D printed version with Shelyak optics.
http://www.astrosurf.com/solex/sol-ex-presentation-en.html

Probably about $1000 excluding the camera.

[Saturnine]

Really like your work and explanations of the physics etc involved and what is seen at the different band passes. Can't pretend to understand all of it but know more now than I did a few years ago. Just enjoy seeing the Sun in 1.0A Ha.

[Eris]

Ken once again you have shown us an interesting image set backed up with a knowledgeable explanation of how things work. Congratulations well done.:thumbsup:
Something Mr Lunt may wish to consider!