2.06.2020 Solar surface and prom.

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Tuesday 2nd June, bright but with lots of thin cloud. It must be those new-fangled aeroplanes they have just re-invented. We have seen several vapour trails this week.

Before the pandemic there would be several planes simultaneously, overhead throughout the day and night. When the atmospheric conditions were just right the trails would last for ages. The entire sky would be literally crisscrossed with trails. 

11.00 75/68F. There is a whopping great filament just above the disturbed area!

11.12: First and only image: Yuk!  Over-sharpening by AS!3 before ImPPG? How does that work? The PST etalon is showing its stripes too. The so-called "sweet spot" can sometimes be tuned out by judicious waggling of the inner etalon tuning ring. Though I really don't recommend it.

Too cloudy to penetrate through to the sun! I think I'm wasting my time today! The forecast was for clearer skies this afternoon. I'll try again later.

11.39. Or, not. I bunged the 1.6x T-S GPC on the camera nose and was treated to some brief sunshine. It seems to have bored though the cloud.

Timing my captures for still, clear moments helps [as usual.]

I need a sun visor! I'm wearing an old baseball cap for the long peak but it is too warm at 77F [and still climbing] inside the dome. Though, naturally, I'm sitting in the shade as usual. That is one of the huge advantages of a dome!

I keep looking at the SharpCap live screen on the monitor but the seeing has gone to hell!  Totally out of focus. Like thick mist! I have the brightness on the observatory wall but the sky is all, soft stripes.

17.55 Late afternoon I went over to check the seeing. Quite steady but coming and going out of focus.

18.56 Prom action! The most amazing prom at about 2 o'clock.

I was seeing incredible detail on the monitor through fierce thermal trembling but it seemed not to translate into an image.

Then the trees took over.

The camera felt very warm and had reached a previously unmatched 49C!

It is fascinating to watch the live video on the 27" monitor. I am the victim of my own folly in using such a long, equivalent focal length. With the 1.6x GPC I am probably getting 1.3x amplification for 1950mm f/l. The 1.6x relates to the long glass path length of binoviewers.

Theory says that you don't use large apertures with long focal lengths because they are so sensitive to seeing condions. Yet, if I didn't scale up the image it would be insignificant.  

It was hovering around 80F inside the open dome with full sun and 70F in the shade outside. So the dome was adding its own, thermal, convection currents. I keep wondering if I shouldn't be painting everything white. Or literally sliding the dome out of the way on rails. ROD! Roll off dome, anybody? This would reduce the thermal impact of the dome on the local seeing conditions. Though that ignores the large shed roof right alongside the observatory.

The downside is having a large white "balloon" sitting permanently above the garden. The dome is flaking badly due to the cheap crap undercoat/primer I used. I should have painted the sage green, wood protection paint straight onto the birch plywood panels. Ah, the wisdom of perfect hindsight!

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