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Walking on the Moon

C/2020 V2 (ZTF) Animation.

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Wednesday night Thursday morning was a clear until dawn 

I had the RC10 out early but had teething problems to start with:

Problem solved I played about until the comet got a bit higher, although it's visible right through the night now from my observing spot at home. With the comet getting quite big and bright I realised that the RC10, even with the 0.8 reducer wasn't the instrument for big beautiful comet images. So decided to do a looooong animation, in the hope that I'd be able to pick out some dynamic changes in the ion tail. Maybe a knot of increased brightness or something. The vague plan was to start collecting subs a soon as possible and run it until dawn. So intially I thought about 300 x 60 sec subs.

I got the comet framed nicely and then dedided to use the comet guiding routine in PHD2. In needs some training but seemed to work well but on blinking the first few subs, it was evident that the comet was still drifting accross the field and I wasn't sure where it would end up once I go to bed and leave it to look after itself. So I switched back to normal guiding with the nucleus of the comet selected as the guide star. This worked excellenly and even with guiding fighting the phenominal motion of the comet relative to the stars, I was getting better than 2 arc sec guiding, mostly.

I knew there was  meridian flip due about 04:50 but left APT to look after that. I'd have enough data before that so no big deal if it goes pear shaped. 

The flip worked perfectly. But PHD2 just resumed guiding on a star and not the comet (and why would it?). The Subs after that were lovley and sharp but the comet was drifting rapidly accross the frame. 

So of the 300 or more subs I took, the early ones were spoiled by drift and me trying to fix it and the last few due to the flipping flip.

ASTAP has a blink feature that can export to video file but for some reaswon it wouldn't demosaic the images automatically as I'm sure it has done in the past. Gave up after an evening of trying. Had to do it the long way. Convert the 176 good subs to TIF so I could work in P.S. to make a simple stretch, curves and RGB align routine to run on them. That worked ok. Then still in P.S. created an animation sequence and GIF.

The image processing worked well but I think I needed to be more agressive to get more detail in the ion tail. The early subs were affected by the comets low elevation. I don't think I can pick out any dynamic deatil in the ion tail. Mostly just variabillity in sub quality I think. 

Anyway, as ever, what follows probably isn't worth all this writng ...








Edited by Paul M
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