Comet C/2021 A1 (Leonard)

Phil opened Carrs Mill at 0200 this morning for the purpose of observing and imaging C/2021 A1 (Leonard). John Nagy and James Willinghan were present as well. The forecast during the preceding 24 hours, and the observed weather conditions when I woke up at 0115 and when I arrived an hour later were not promising at all.

The equipment that I selected for this session, based on indications of an extended tail length that I was seeing on line, was the Canon 60Da (APS-C) and 50mm lens. The camera was mounted on the Omegon LX-2 mini wind-up tracker. Image capture was managed with Backyard EOS running on my laptop. All equipment and software functioned as designed during the entire session.

The sky was almost completely clouded out and the wind gusts were quite strong when I arrived at Carrs Mill at 0215. There was no dew at any point during the entire session. The temperature was about 45 degrees and remained steady during the session.

I spoke briefly with Phil, John and James before electing to defer setting up equipment until conditions improved. While waiting, I sat in the Jeep to keep myself out of the wind. The Big Dipper and Arcturus were intermittently visible through and between the clouds. I used these points and the time inside of the Jeep to get my bearings.

The weather looked like it was breaking, so I hopped out of the Jeep and set up equipment at about 0315. By the time I finished, the eastern sky had clouded up again. I returned to the Jeep for about 30 minutes, at which time the clouds had abated.

By about 0350, conditions had greatly improved, and the wind had died down. I got out of the Jeep to perfect the framing, focus, and exposure values.  As a result of not having using the tracker in a while, I experienced some difficulty with getting it on the target, but not too much. After perfecting my focus, I began to snap preview images to get my focus and framing correct.

Next I initiated a run to capture 100 light frames. My exposure settings were TV=4s, AV=305mm, aperture = f/2.8. I examined a couple of frames and found the comet’s tail did not appear nearly as long as planetarium software projected. Maybe stacking will pull out more detail.

After capturing 100 light frames and 50 dark frames, I packed the equipment back into the Jeep. After chatting with Phil, John and James again, I departed Carrs Mill at about 0535.

As for afterthoughts, my operating focal length was way to short for the job. I am not expecting much out of my final image. Also, there is something off about the images of the comet that I did capture. It seems that I might have already decided that the 60Da is not my best cometary sensor, but I want to look into that again.

I would like to image the comet again before it becomes an evening object. I think that I want to use my Pronto with the ASI178MC. Weather doesn’t look so good, so I have a wait ahead of me.

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