Comet C/2022 E3 (ZTF) 3.5 Hour Time-Lapse Animation (January 24, 2023)

Here's something different! This is Horizon co-founder Brandon (BJG) here. I photographed this comet from my backyard in Summerville, SC. See and download the full-quality version here on Flickr: https://www.flickr.com/photos/ilikerio/52670627107/in/album-72157687321039346/ For those of you who didn't know, I started an exciting new adventure into the realm of astrophotography way back in 2018. This hobby is extremely challenging (and expensive), but capturing beautiful images, sharing them with the world, and inspiring other people makes it all worthwhile. I've learned a lot over the past few years and I'd love to share more of my work here if some of you are interested!

C/2022 E3 (ZTF) is a long-period comet from the Oort cloud. It reached perihelion (1.11 AU from the Sun) on 01/12 for the first time in 50,000 years. Since its orbit has changed, the comet will either return in many millions of years or be ejected into interstellar space. On 01/24, the comet clearly displayed an ion tail, dust tail, and rare anti-tail as Earth passed through its orbital plane. The green glow in the coma is the emission of diatomic carbon. It passed 0.28 AU from Earth on 02/01.

On the morning of 01/20, I took a huge gamble and tried to shoot this comet with my new Tamron 70-200mm f/2.8 lens. It was a massive sacrifice to sleep 3 hours, wake up at 02:00 EST, set up/troubleshoot the previously untested rig, shoot until dawn, pack everything up, and leave for a long, exhausting work day. After stacking the images later that day, I was extremely disappointed with the result.

The otherwise fantastic lens suffers from internal reflections that are impossible to correct or remove. I spent days desperately trying to salvage the data with new calibration frames, different focus distances, etc., but I realized it was no use. From what I can tell it seems to be a pupil ghost (https://www.cloudynights.com/topic/536295-flat-not-correcting-central-donut/) caused by the glass elements and/or reflective rings inside, and there is no solution. I would have discovered the issue if I had tested it before. It was an excruciating lesson to learn.

Somehow, I was lucky enough to get another clear morning on 01/24. This time, I switched back to my trusted and proven deep-sky telescope. I woke up at 01:00 (4 hours of sleep), set everything up to start shooting around 03:00, packed up at dawn, and left for another long, painful day at work. Comet image processing was another mountain to climb, but I figured out a good workflow (influenced by Adam Block's technique: https://youtu.be/TaEwvC1lzKM) after 10 days of experimenting. The hard work has finally paid off and I'm super proud of this result!!

For anyone interested, I wrote up a thorough summary of my PixInsight image processing journey here: https://www.cloudynights.com/topic/862530-comet-c2022-e3-ztf-30-hours-of-processing-on-2-hours-of-exposure/

Total integration: 2 hours 8 minutes
128 x 60 seconds ISO1250
01/24/23 07:55 to 11:25 UTC

Camera: Canon 7D Mark II
Telescope: Explore Scientific ED80 f/6.0 Apochromatic Refractor (with ES field flattener)
Mount: Orion Sirius EQ-G
Guide scope: Svbony 50mm f/4.0 Guide Scope
Guide camera: ZWO ASI224MC
Capture software: N.I.N.A., ASTAP, PHD2
Bortle Class 6 ~19.32 mag/arcsec^2 (Summerville, SC)
Processed with PixInsight and Paint.NET

Видео Comet C/2022 E3 (ZTF) 3.5 Hour Time-Lapse Animation (January 24, 2023) канала Horizon Productions SFL