Nicknamed “the green comet”, its closest approach to Earth was on 1 February 2023 (two nights after this image was taken). The nucleus is only around 1km wide.
I wasn’t sure I’d be able to image this comet as the weather has been so bad lately. There was a brief gap in the clouds though, so I gave it a go.
Framing it was tricky. My ASIAIR Plus did a good job of plate-solving, and got the comet within the field of view of my ZWO ASI2600MC Pro camera, despite the relatively tight 1000mm focal length of my Askar 130PHQ telescope. I tried taking a 120-second subframe, as is standard for me, but the comet appeared as a streak; evidently it was moving fast in the sky! I adjusted to 30-second subframes instead. I took a few and tried to work out which way the comet was moving in the sky, then moved the mount a little in that direction so that the comet would move into the centre of the frame, rather than out of it. Turns out that didn’t matter too much in the end as the cloud returned about an hour later. I also didn’t take the full size of the tail into account (to be fair, it wasn’t visible at all in the single subframes), so in the end I had to crop in quite a bit and I’d cut the tail quite short. Processing was tough too. I followed this guide from the YouTube channel View into Space.
But still, I imaged the comet from a city centre during a gap in seemingly never-ending clouds! I’ll take that as a win.
Here’s the comet’s path over the hour:
Imaging details
* 30 January 2023
* Bristol, UK (Bortle 8)
* Telescope: Askar 130PHQ Flatfield Astrograph
* Camera: ZWO ASI 2600MC-PRO
* Mount: Sky-Watcher EQ6-R PRO
* Guide: William Optics 50mm Guidescope with 1.25″ RotoLock; ZWO ASI 120MM Mini
* Control: ASIAIR Plus
* Software: PixInsight, Lightroom
* Filters: none
* 105 x 30 seconds
Total integration time: 52.5 minutes
By Lee Pullen
Example source data
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