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Spectroheliograms 19Jun2017

Posted: Wed Jun 21, 2017 2:15 am
by p_zetner
Greetings Everyone.

Back in action with my spectroheliograph.

Here are two "test shots" with my reconfigured SHG using the Celestron NexStar 4SE as telescope. Two big advantages of this scope: a motorized focuser and less glass (than my previous Astro-Rubinar lens) to give better UV transmission.
161147_Halpha_154807_Ca_K3_labels.png
161147_Halpha_154807_Ca_K3_labels.png (1.96 MiB) Viewed 4424 times
A picture of the instrument:
SHG Jun2017.png
SHG Jun2017.png (780.95 KiB) Viewed 4424 times
Pretty happy with the new arrangement so far. Focusing the Astro-Rubinar telephoto was a pain.
I was able to take advantage of cooperative weather for an extended, multi-wavelength imaging session today (20 Jun).
Hope to process and post the new images soon.

Cheers.
Peter.

Re: Spectroheliograms 19Jun2017

Posted: Wed Jun 21, 2017 7:45 am
by Merlin66
Wooh.......
That's a very difficult balancing job!!!
Great results, look forward to seeing more.
(No ERF?)

Re: Spectroheliograms 19Jun2017

Posted: Wed Jun 21, 2017 5:00 pm
by marktownley
I always enjoy seeing your work Peter! Great stuff!

Re: Spectroheliograms 19Jun2017

Posted: Wed Jun 21, 2017 8:19 pm
by p_zetner
Thanks Mark and Ken.

Ken, here's another view of the SHG with more of the construction details visible. The entire instrument weighs about 12kg. It's not terribly more unwieldy than the previous version but I can notice flexure when viewing afternoon Sun as opposed to morning Sun. I'm trying to think of an improved mounting arrangement for the Celestron. At the moment, you can see the aluminum bar and rod used to support its weight. You can also see the counterweight on sliding bar which I use to balance (in dec).

I don't use an ERF on the Celestron. From what I can tell, apart from the corrector plate, there are only reflective optics. The Astro-Rubinar had cemented achromats near the focus.
IMG_0622_crop.jpg
IMG_0622_crop.jpg (516.85 KiB) Viewed 4398 times
Cheers.
Peter.

Re: Spectroheliograms 19Jun2017

Posted: Fri Jun 23, 2017 12:35 pm
by highfnum
wow looks complicated but works well
nice to see others doing this

Re: Spectroheliograms 19Jun2017

Posted: Sat Jun 24, 2017 10:20 pm
by Phil Rousselle
Hi Peter, your SHG is very long but works fine. K3 image has a very good bandwidth and contrast
Phil

Re: Spectroheliograms 19Jun2017

Posted: Sun Jul 02, 2017 9:46 am
by Carbon60
Very nice SHG images, Peter. Always good to see your work.

Maybe mount everything rigidly in a lightweight wooden box.... It would take away some of the beauty of this arrangement, but might make for a more stable instrument. It looks impressive, but precarious :)

Stu.

Re: Spectroheliograms 19Jun2017

Posted: Sun Jul 02, 2017 2:57 pm
by Merlin66
Stu,
That's what I did with the 100mm Littrow SHG, see:
viewtopic.php?f=8&t=20682

Re: Spectroheliograms 19Jun2017

Posted: Tue Jul 04, 2017 11:22 pm
by p_zetner
Thank you all for your comments.

Phil: You should know that it was your work that motivated me to pursue "spectroheliography" in the first place! Your spectroheliograms are inspirational and your website very informative. I encourage all aspiring spectroheliographers to read through it. Thanks for the visit.

Stu: Your comments are always welcome. The suggestion of the wooden support box is good (see Phil Rousselle's original design!) but, aside from experimenting with some minor tweaks, I'm reasonably happy with my configuration at the moment. I'm planning a much larger instrument which will necessarily be housed in a box of some sort and fed sunlight through a coelostat ... a long term project!

Cheers.
Peter.

Re: Spectroheliograms 19Jun2017

Posted: Wed Jul 05, 2017 11:21 am
by Montana
Wow, the images are lovely and a great set up too :bow :hamster:
Alexandra