The Sun 10th Feb 2019 - A Bit Of An Experiment

[David Smith]

I've been considering a short focal length frac to get solar full disk images for a while now and when one came up on ABS the other week I took the plunge and picked up a Bresser AR102xs. It's focal length meant that I could potentially get a solar full disk with my ASI178 in one frame, great for grabbing a disk quick when the weather's not so great (when isn't it). I've also got half an eye on an upgrade to my H Alpha setup which might include a Quark bolted to a short focus frac, so this fits the bill again.

I managed a quick and dirty first light the day after I collected it but didn't really draw any conclusions due to the rushed nature of the session. Today I had a longer session and managed to explore both white light and Ca-K with this scope. After that initial look with the scope I did not think I could get focus with the Herschel wedge but I managed fine today! It is kind of tough to judge the results with no detail to be seen though.

The Ca-k is more worrying to be honest, the concern with Ca-K is spherical aberration which limits sharpness in the final image and results here don't look great to me. The advantage of doing a full disk in one shot is that I can combine surface and prom layers like this.

 

Not sure if I am just expecting too much from the little scope after being spoilt by my Evostar 120 for so long, or whether there is actually an issue. Jury's out until I get a session in with a nice AR to look at and in the meatime I wil try some night-time wide field viewing.

 

 

 

 

[Pete Presland]

The white looks fine, but the Ca-k does look a little soft, it might have been the conditions though. I also bought a short tube frac for the same reason last year. A softer image is better than no image though.

[xtreemchaos]

good images for your firstlight David, conditions wasnt the best here, well done. charl.