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Fridays Calcium Images - 5th July

Posted: Sun Jul 07, 2019 8:55 am
by marktownley
The sky was beautifully transparent on friday morning, deep blue and lacking in any haze, so I decided to have a go at some calcium imaging, and at the same time test out the Grasshopper 3 IMX174 at these shorter wavelengths for some closer images. First up though the full disk, prime focus with the 100mm Tal refractor at 1000mm focal length, using the homebrew CaK filter and the GH3 ICX916M camera, make sure you double click for the full size view in flickr.

ImageCak-FD-bw by Mark Townley, on Flickr

ImageCak-FD-colour by Mark Townley, on Flickr

You can just about make out the inverse granulation that is visible. Granulation is a feature of the photosphere we can see in white light, where cells of solar plasma rise and fall. The edges of the cells are cooler with the falling plasma and so the boundaries appear darker - regular granulation. With inverse granulation we are viewing the same features at the base of the chromosphere, here the cells themselves are a lot cooler than their edges, so, the cells are darker and the cell edges / boundaries appear lighter. It's all about 'relative' light levels in the same way that sunspots appear dark on the solar disk, despite them being only slightly 'cooler' than the surroundings they sit in.

Anyways, zooming in with the same scope and 3x barlow with the GH3 IMX174 camera this time with its larger pixels I set out to explore the sun. First off the region of plage that is associated with the active regions that first appeared at the end of march / beginning of April.

Imageex-ar-cak-bw by Mark Townley, on Flickr

Imageex-ar-cak-colour by Mark Townley, on Flickr

I wonder in another couple of weeks time there will still be some plage remaining, albeit at diminished extent? A small emerging flux region was also visible in (cycle 24) equatorial regions, that may well have just sported a few pores briefly.

Imageefr.-bw by Mark Townley, on Flickr

Imageefr.-colour by Mark Townley, on Flickr

Turning my attention to the poles, and polar faculae indicative of solar minimum were visible in both hemispheres:

Imagenpole-cak-bw by Mark Townley, on Flickr

Imagenpole-cak-colour by Mark Townley, on Flickr

Imagepolar-cak-bw by Mark Townley, on Flickr

Imagepolar-cak-colour by Mark Townley, on Flickr

First impressions are I like this camera at CaK wavelengths, probably more so than at Ha, the fast frame rate certainly helps. I think next steps will be to try it out with the SSM to get better data to play with. All these were stacks of only 16 images. Did get some Ha too, but will have to wait till later to process them.

Mark

Re: Fridays Calcium Images - 5th July

Posted: Sun Jul 07, 2019 11:59 am
by pedro
Beautiful CaK images Marke, great definition. The IMX174 works well in CaK

Re: Fridays Calcium Images - 5th July

Posted: Sun Jul 07, 2019 12:25 pm
by MapleRidge
Hi Mark...

Superb CaK images for this data set...excellent work :bow

Also great explanation of the difference in the granulation between the two filters...thanks!

Brian

Re: Fridays Calcium Images - 5th July

Posted: Sun Jul 07, 2019 4:28 pm
by marktownley
Thanks Pedro, thanks Brian! :)

Re: Fridays Calcium Images - 5th July

Posted: Sun Jul 07, 2019 5:50 pm
by MAURITS
Great results Mark.

Re: Fridays Calcium Images - 5th July

Posted: Sun Jul 07, 2019 7:22 pm
by krakatoa1883
Great images, and explanations, Mark. Is the full disc a mosaic ?

Re: Fridays Calcium Images - 5th July

Posted: Sun Jul 07, 2019 7:36 pm
by marktownley
Thanks Maurits, thanks Raf. The full disk is one image, not a mosaic Raf.

Re: Fridays Calcium Images - 5th July

Posted: Mon Jul 08, 2019 11:12 am
by Montana
Another excellent and informative post Mark :bow2
Superb set of Calciums too :bow :bow

Yes it was a gorgeous day on Friday, I had high hopes for Saturday and it poured with rain all morning until around 2pm, then had to trim the hedge as the neighbour was anxiously waiting to turf his lawn. I think we were the only place in the UK to get this band of rain, typical.

Alexandra

Re: Fridays Calcium Images - 5th July

Posted: Tue Jul 09, 2019 5:31 am
by Carbon60
Excellent post, Mark. Informative and with beautiful images.

I was in Redditch on Friday and experienced the same conditions that you did. Unfortunately I didn’t have any solar kit with me. Picnicked with family in the Park instead.

Stu.

Re: Fridays Calcium Images - 5th July

Posted: Tue Jul 09, 2019 6:06 am
by marktownley
Thanks Alexandra, thanks Stu.

Here is the Ha from the same day. I think the CaK is my preference from the session. FD with the SM90 and GH3 ICX916M, closeup same scope with the 3x barlow and GH3 IMX174...

Imageha-fd-bw by Mark Townley, on Flickr

Imageha-fd-colour by Mark Townley, on Flickr

Imageex-ar-ha-bw by Mark Townley, on Flickr

Imageex-ar-ha-colour by Mark Townley, on Flickr

Looks like cloud for the week for me now!

Re: Fridays Calcium Images - 5th July

Posted: Tue Jul 09, 2019 7:40 am
by Martin_S
Great pictures Mark . Do you have a link to your homebrew CaK filter? the results are amazing.

Martin

Re: Fridays Calcium Images - 5th July

Posted: Tue Jul 09, 2019 1:16 pm
by MAURITS
Excellent, with some nice details Mark.

Re: Fridays Calcium Images - 5th July

Posted: Sun Jul 14, 2019 1:25 am
by MapleRidge
Superb addition of Ha images Mark...excellent work :bow

Brian

Re: Fridays Calcium Images - 5th July

Posted: Mon Jul 15, 2019 5:55 am
by banjo
Great Picture , :bow :bow :bow :bow :bow
Paul