H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

I LOVE finding out about different ways to appreciate the Sun and light in general. Use this forum to post your info or questions about various outside the mainstream ways to appreciate our life giving star!
Post Reply
thesmiths
Almost There...
Almost There...
Posts: 1053
Joined: Mon Jun 04, 2012 8:13 pm
Location: London, England
Has thanked: 42 times
Been thanked: 1485 times

H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by thesmiths »

The weather remains sunny in London and now it's not so hot. The early morning gave some good seeing conditions. Another 330 GB of disk spaced used up by SHG video files, this time with H-alpha and H-beta (yesterday's H-alpha and Ca-H was about the same about of GBs). Two wavelengths is about what I can do while the Sun is in a favourable position.

H-alpha SHG. 720mm focal length, 106mm aperture. 2400 l/mm grating, 9 micron wide lithographic chrome on quartz slit. Stack of 11 frames (out of  20).
H-alpha SHG. 720mm focal length, 106mm aperture. 2400 l/mm grating, 9 micron wide lithographic chrome on quartz slit. Stack of 11 frames (out of 20).
070822-Ha-720mm-stack-11.jpg (2 MiB) Viewed 1742 times

The images are best seen at full resolution by opening in a new tab. You can toggle between the two images by switching between tabs. Use the little magnifier to click on an area to examine more closely (the size of the images are 3000 x 3000 pixels).

H-beta SHG. Stack of 13 frames (out of 19).
H-beta SHG. Stack of 13 frames (out of 19).
070822-Hb-720mm-2400g-stack-13.jpg (2.05 MiB) Viewed 1742 times

I also made some full size crops that fit on the screen better. The lower portion of images show some interesting structures that came out nicely inverted.

H-alpha SHG, inverted.
H-alpha SHG, inverted.
070822-Ha-720mm-stack-11_crop_invert.jpg (651.67 KiB) Viewed 1739 times
H-beta SHG, inverted.
H-beta SHG, inverted.
070822-Hb-720mm-2400g-stack-13_crop_invert.jpg (652.24 KiB) Viewed 1739 times
Last edited by thesmiths on Tue Aug 09, 2022 8:48 pm, edited 1 time in total.


User avatar
fulvio.mete
Ohhhhhh My!
Ohhhhhh My!
Posts: 116
Joined: Tue May 20, 2014 8:59 am
Location: Rome, Italy
Been thanked: 84 times
Contact:

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by fulvio.mete »

Very nice images, Douglas!


User avatar
hopskipson
Im an EXPERT!
Im an EXPERT!
Posts: 328
Joined: Sun Jan 13, 2019 9:27 pm
Location: Queens, NY
Has thanked: 404 times
Been thanked: 191 times

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by hopskipson »

I really enjoy your images Douglas!

I’m currently using the Sol’Ex but am limited by the slit to 480 mm focal length for a full disk. Is it possible to get a longer slit or would I need to modify the entire sgh?


James
These pretzels are making me thirsty! (C.C.)
The Quark introduced me to this wonderful side of the hobby and the sun hasn’t disappointed yet.
Solar Equipment: Solar Spectrum RG-18 0.3A, Coronado Solarmax 90mm etalon Isle of Man SN-001, Tuscon SN-380 and Meade SM2, Lunt LS80 DS, Quark Chromosphere, Lunt 2" wedge, 2-Lunt CaK II 1200, Baader 3.8 and 5.0 solar film in 208mm cells, and 3D printed Sol'Ex SHG, Lunt 40mm
Coming Soon: Solar Spectrum CaK II <1A filter
thesmiths
Almost There...
Almost There...
Posts: 1053
Joined: Mon Jun 04, 2012 8:13 pm
Location: London, England
Has thanked: 42 times
Been thanked: 1485 times

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by thesmiths »

hopskipson wrote: Sun Aug 07, 2022 6:22 pm I’m currently using the Sol’Ex but am limited by the slit to 480 mm focal length for a full disk. Is it possible to get a longer slit or would I need to modify the entire SHG?
The Solex design is fairly optimised so that all the lenses, slit, grating work together. You could probably figure out how to fit a longer slit onto the collimator, but the 25mm diameter optics means you probably don't have more than about 6mm which will be in good focus at the same time. So that means you can probably get to around 650mm focal length for a single scan.

I discovered also that with a long slit you need to have a way to adjust for tilt of the slit and I think also for tilts of the other optical elements.

Finally, take into account the magnification of the system. With the 80/125 standard Solex design, the image size at the sensor will be 9.4mm for a 650mm focal length. So you might need a larger camera sensor. Alternatively, consider replacing the 80mm focal length lens with another 125mm lens to reduce the magnification to 1. But then the collimator needs to be redesigned for the longer focal length.

So as you can see, you start to open up a can of worms when you think about doing a longer focal length in a single scan. The other way is to just do 2 scans and mosaic them together.


thesmiths
Almost There...
Almost There...
Posts: 1053
Joined: Mon Jun 04, 2012 8:13 pm
Location: London, England
Has thanked: 42 times
Been thanked: 1485 times

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by thesmiths »

hopskipson wrote: Sun Aug 07, 2022 6:22 pm I’m currently using the Sol’Ex but am limited by the slit to 480 mm focal length for a full disk.
I just noticed this nice image by my friend Jean Francois (JFP), who also uses the standard Solex. He made the following nice image using a 102mm focal length telescope, just with 3 passes and then did a mosaic http://www.astrosurf.com/uploads/monthl ... 262d0b.jpg

He is the one who introduced me to the idea of stacking SHG images. He's quite good at building things but he admitted that attempting to put a long slit into a Solex would be a total rebuild, so he is sticking to making mosaics for now. Here is the link to his full post on astrosurf: http://www.astrosurf.com/topic/156088-s ... ohp-solex/


User avatar
Montana
Librarian
Librarian
Posts: 34526
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17521 times
Been thanked: 8763 times

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by Montana »

Fantastic images Douglas :bow :hamster:
Do you know what height in the chromosphere hydrogen beta is looking at?

Alexandra


thesmiths
Almost There...
Almost There...
Posts: 1053
Joined: Mon Jun 04, 2012 8:13 pm
Location: London, England
Has thanked: 42 times
Been thanked: 1485 times

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by thesmiths »

Montana wrote: Tue Aug 09, 2022 11:42 am Do you know what height in the chromosphere hydrogen beta is looking at?
That's a really interesting question. I had a look around and the best I could find was the following statement regarding H-beta: "the features originate from a height region in the solar atmosphere that spans the photosphere (the ‘surface’ of the sun) and the chromosphere". https://nso.edu/press-release/first-hig ... lar-image/

Compare to this statement: "The hydrogen-alpha and calcium-K bands are those that show the most excitingly distinct features compared to broadband observing. Hydrogen-alpha light shows the middle to upper chromospheric features, including filaments on the disc and the highly dynamic prominences visible at the limb. It also gives a different perspective on sunspots and reveals the magnetic active areas that do not show spots. Calcium-K light reveals a lower, cooler layer of the chromosphere, showing the bright chromospheric network, plage, and the magnetic regions strongly." https://britastro.org/journal_contents_ ... narrowband

I also found this interesting webpage, which does not really answer your question but has an interesting story to tell: https://www.icstars.com/apage1/2011/2011_Sept01.html

The Internal Structure of the Sun
The Internal Structure of the Sun
sun_interior.jpg (188.89 KiB) Viewed 1659 times
Last edited by thesmiths on Wed Aug 10, 2022 10:48 am, edited 1 time in total.


User avatar
Montana
Librarian
Librarian
Posts: 34526
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17521 times
Been thanked: 8763 times

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by Montana »

Very interesting!! the third link shows that h-beta is very similar to the wings of h-alpha (the offband image in h-alpha that they show). So I reckon it's height is between halpha and photosphere.

Alexandra


User avatar
marktownley
Librarian
Librarian
Posts: 42120
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20229 times
Been thanked: 10111 times
Contact:

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Post by marktownley »

Montana wrote: Wed Aug 10, 2022 6:29 am Very interesting!! the third link shows that h-beta is very similar to the wings of h-alpha (the offband image in h-alpha that they show). So I reckon it's height is between halpha and photosphere.
Yup, sounds right to me.


Image
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!
Post Reply