Hello Nick and colleagues

My apologies - it was meant to be right way round and North up but I was popping out to my observatory in between bouts of coughing - aftermath of a cold I haven’t totally shaken yet - and the camera was loaded on the scope in the dark with more haste than usual.

The FITS images were processed needing a vertical flip and should have finally come out the same orientation as my 12P images from the day before.   But it is possible in my confused state yesterday I flipped the images twice instead of once. I will go back to the original data and work out what has happened.

Both stacked images had to be heavily cropped before processing as the comet moved across the field of view so far in a short time. But the original star field image can be plate solved to answer the scale and orientation question. I know from past experience that the image scale from the camera will be around 0.361 or 0.362 arc secs per pixel.

Regards,

Peter

Sent from my iPhone

> On 9 Nov 2023, at 06:50, Nick James <ndj@nickdjames.com> wrote:
>
> Peter,
>
> Thanks. Those are nicely processed images which pick up both the faint ion tail in PA 25 and the small spike in the opposite direction. As you say, this is a very fast-moving comet so needs stacks of short exposure subframes.
>
> Thanks also for submitting your images to the archive. Could you add the orientation and field of view in the caption please? This helps a lot when it comes to analysis. From comparison with other images your image either doesn't have north at the top or it is mirror imaged but it is hard to tell which.
>
> This is not so important with planets since you can generally quickly tell the scale and orientation. It is much more difficult with comets!
>
> Nick.
>
>
>> On 09/11/2023 00:51, Peter Tickner - peter.tickner1472 at btinternet.com (via baa-comet list) wrote:
>> This isn't too far in the sky from 12P so after an abortive attempt on 6th
>> November I managed some stacks of it on 7th November.  Very bright and very
>> fast moving!
>>  I'll send a set for the archive as well.
>>  Peter
>>  Flickr link: https://flic.kr/p/2peFdBy
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