Sunday 12 November 2017

Ha Full Disk - 12th November


It has been some time coming; the full disks I was getting from my trusty DS40 came to an end last year when a slip de-contacted one of the etalons.  I was able to recontact it but I was never completely happy with the results, there was banding and an uneven field of view.  I purchased a 50mm double stack etalon around this time as it was a bargain price, and then only very recently got round to buying the Lunt50 scope to go with it - once you double stack you never go back!  Totally the wrong time of year with a very low sun and poor weather, not to mention the demise into solar minimum, but it is nice to get the full disk overview in Ha.

Conditions couldn't really have been much worse, a direct northerly wind meant the temperatures at 500mB were very low, meaning much instability in the atmosphere.  Throw in the 'Cheshire Gap' effect where the weather blows in straight in between the high ground of North Wales and the Peak District funneling clouds over the West Midlands, and the clear blue skies were just a wolf in sheep clothing.  This time of year the low sun has dropped into the trees from my yard, and I only have a some brief windows of branch free viewing in between the foliage, so I was keen to make the most of things.  

I'm not used to the pressure tuner system, let alone the double stack, but I was pleased with this result that I got at prime focus (350mm) with the DS50.  The camera was the PGR Chameleon 3.  Not much to see on the sun at the moment, the filaments appearing to be associated with the long distant relics of active regions of old.  Not sure how much use I will get out of the scope this winter, another year passes and the trees on my souther horizon get bigger meaning less viewing time.  I will certainly try though if blue skies present themselves.