Recognising the various threads and the great contributions being made, I've put together a summary document which shows examples of CaK filaments from SHG and commercial CaK filters.
Scanning my solar book collection; Zirin, Noyes, Loughhead, Phillips and Abetti only gave a few examples of CaK filaments - all from Spectroheliographs.
Phillips - Fig6.6 p115 "...but the filaments are barely visible"
Abetti -Plate 52 (Meudon, 1930), Plate 54 (Meudon, 1949), Plates 65-68 (Meudon 1929) Impressive sequence of images.
My conclusions:
1. A CaK filter/system with a bandwidth <0.4A is necessary to give high contrast images of filaments in CaK
2. Filaments are easier to image on CWL and just below (into the blue wing <0.2A)
3. Filaments, if recorded with bandwidths >1A usually appear washed out and ghostly.
MiniSHG and filaments
- Merlin66
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MiniSHG and filaments
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
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"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
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"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
- Montana
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Re: MiniSHG and filaments
That's a great summary Ken, you should pop it into the library in a few days
Alexandra
Alexandra
- marktownley
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Re: MiniSHG and filaments
Great summary Ken.
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
- pedro
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Re: MiniSHG and filaments
Great doc Ken, thanks for sharing
Pedro Re'
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