On Sunday morning, we got up at 4:00 AM to drive to a spot with a long view to the East to go comet hunting.  I successfully got the telescope set up prior to the time when Comet Tsuchinshan-ATLAS C/2023 A3 was supposed to rise.  However, when the comet did rise, the ASIAIR could find stars, but couldn’t plate solve to figure out if it was pointing exactly right.  So I ended up starting imaging without having successfully scanned to the predicted comet location.  Since I could see a tiny comet in the first shot, I let the system take an automated sequence of shots.  60 second shots were too bright, so I started with 10 second shots, and when they became too bright, I switched to 1 second shots.

I also tried taking pictures with an 85 mm lens on my Canon EOS 60D, but that didn’t pick up the comet at all.  What it did pick up was the reason I didn’t get very many good comet images … clouds!  Of course, clouds are terrible for astrophotography, but they do lead to nice sunrise pictures.

We stayed for the sunrise, went out to breakfast, and then headed home.

Astrophotography is really two hobbies: capturing the images and processing them.

When we got home, I worked on processing the images I’d gotten.  I could see the comet in the 10 second images and in the 1 second images, but the 1 second image ones were generally partially through the clouds.  So I ended up using only the 10 second images.  Because there weren’t any stars captured in these short images, I only needed to process for the comet and use Comet Alignment to align the frames.

I’m hoping that I’ll get some better images later this fall.  Are you making plans to try to see this one?

Camera geek info:

• Williams Optics Zenith Star 73 III APO telescope
• Williams Optics Flat 73A
• ZWO 2” Electronic Filter Wheel
• Antila RGB filters
• ZWO ASI183MM-Pro-Mono camera
• ZWO ASiair Plus
• iOptron CEM40
• Bacliff, Texas Bortle 6 suburban skies

Frames:

• 4 10 second red lights
• 7 10 second green lights
• 5 10 second blue lights
• 30 0.02 second flats for green and blue
• 30 0.05 second flats for red
• 30 0.02 second flat darks for green and blue
• 30 0.05 second flats darks for red
• 1 second dark from library 

Processing geek info:

• PixInsight
• Generalized Hyperbolic Stretch
• NoiseXterminator