Solar Activity 20th Oct 2020

[Merlin66]

The prominent AR2776 and a couple of nice proms.
WL and CaK - Ha to follow.
(Will improve the processing of the proms...promise!)
Enjoy.

[AstroJunk]

Very nice set of images, I must find some time to get out today!

[Eris]

A great selection of images Ken. Looking forward to seeing your images in Ha.

[Saturnine]

Very nice set of images once again, the proms yesterday were quite specky. the CaK images always impress, is it just the pretty purple colour or the detail in that layer of the photosphere. ( is it a photosphere layer, note to self, should learn more about the Suns' construct ! )

Had a few sunny breaks up here and tried to get some images but not having any luck processing them, so far

[PeterM]

Really nice images indeed Ken, the Ha are going to be stunning no doubt! That big prom looks like it may have gotten bigger today but for me cloud and work have gotten in the way!

[Merlin66]

Jeff,
The chromosphere extends above the photosphere (basically the "surface" of the Sun we see in White light - sunspots, granulation and faculae) by some 2,500 Km
The lower levels of the chromosphere, around 500Km are being imaged when we work "off band" in the wings of Ha. When we go "on band" in Ha we begin to record detail up around 1,500Km. (sunspots, plage, filaments, flares, prominences, Ellerman bombs, spiculae and the surrounding fibrils of any ARs driven by the magnetic fields)



In parallel to the above when we image in CaK, at (or close to central wavelength) we record the solar detail at 800-1,500 Km heights. The most prominent feature is the calcium "network" (or "chromospheric network" of cells) and bright flocculi surrounding the cells(and occasional filament or prom). The cells in the network can be 30,000Km in size and last 10 hr or more. The brighter areas have some commonality with the plage areas seen in Ha.


The colours of the presented images is very subjective. Each observer has his/her likes and dislikes. They are generally "yellow, gold, orangey red" for Ha, "blue violet" for Cak and a "white pink" for WL - loosely based on wavelength.




(A Plug! - "Imaging Sunlight -using a digital SHG" has a few good chapters on commercial solar filters and what can be observed at various wavelengths and resolution"

[Merlin66]

The following images were taken over a period of only a few minutes, using the ED80/ SM60 double stack with the AS1600MM. Firecapture, AS3!, ImPPG.
The sequence shows the visiblity of umbra and penumbra, the surrounding fibrils, plage and filaments as the tuning moves across the Ha CWL.
It's worth checking them out and comparing the variety of detail recorded.
This was with "swimming pool" seeing.....if you have better conditions you should be able to get better results than these.
(Also remember these images have been reduced to Jpegs from 4Mb Tiff files)

[PeterM]

Lovely Ha images Ken Ken! Like them all but the 6th one along really catches my eye. Bravo!

[Eris]

Again, surperb Ha imagery showing up a great wealth of detail Ken.
Congratulations!

[Merlin66]

Thanks, guys...appreciated.
I’m just trying to show the difference your etalon tuning can make.
Well worth the effort to understand the cause and effect of tuning.

[Martin_S]

Great examples of etalon tuning Ken. Thanks for sharing your images.

Martin

[Saturnine]

Ken

Thanks for the lesson on the solar make up that "we" can see, obviously I need to do some homework.
The second set, of mono Ha images are excellent, most impressive detail.

[rustigsmed]

great images Ken - nice to see the varying filters for us non solar savvy people!

[Merlin66]

Thanks guys, your comments and feedback are always welcome:)
We are all on the same journey, we need to hold hands in the traffic.