Sun in Ca II K - Bad seeing 20191110

[Carbon60]

I've been trying out a few different combinations ready for the transit tomorrow. WL was useless because of really bad seeing (I think the worst I've seen). Here's a short animated gif of the turbulence at the limb to illustrate what I mean. This is at reduced speed and limited frames (100) to keep the file size manageable.

20191111_Bad_Seeing by Stuart Green, on Flickr


After some experimentation I ended up ditching the WL option and selecting my Lunt B1800 Ca II K module without any additional filters so as to keep the exposure times as fast as possible and minimise the effect of poor seeing. The scope was my Tecnosky 125mm refractor. Needless to say, the seeing conditions really badly impacted the quality of the images obtained today.

Here's a limb shot, the scale of which I'm hoping to use tomorrow (if I can find a suitable weather window). This was captured using my acA1920-155um camera and a 2.5X PowerMate. If the seeing improves I also hope to use my 5X PM as well.

20191111_CaK_Limb_x2.5_IMX174 by Stuart Green, on Flickr

I finished off with a couple of FDs using the same module with the same camera (2 pane) and a Basler acA2440-75um with 3.45um pixels (4 pane).

2 Pane Basler acA1920-155um
20191111_CaK_FD_Colour2 by Stuart Green, on Flickr

4 Pane Basler acA2440-75um
_20191111_CaK_FD_Mono by Stuart Green, on Flickr

....and the same in colour.
20191111_CaK_FD_Colour by Stuart Green, on Flickr

Thanks for looking.

Good luck everyone who's planning to capture the transit.

Stu.

[ffellah]

Hi Stu: I am impressed you were still able to get something good with such bad seeing.

Franco

[MAURITS]

As Franco said, a really good session Stu.

[bart1805]

Hi Stu, the one without the Barlow, with the 1920 is by far the best. If the seeing tomorrow is as bad as it was today, that would be the one to go for in my opinion. Wish you all the luck (and a great seeing)! Bart.

[marktownley]

Some nice images there Stu. I'd consider stopping that big scope down this time of year, should sharpen things up a bit.

[Montana]

Nice captures Stuart, I am glad I wasn't the only one with bad seeing. I thought it was because I was bedroom window watching and it didn't bode well for the new window if the seeing is awful. Mine were all a bit blurred too but at least I dusted the equipment down for today. I live in hope even though the odds are against me.


Alexandra