This was three hours of 8 second exposures on 28 May 2024, competing against the waning moon.

Skywatcher 350 goto, ZWO ASI2600MC PRO cooled to -15c, Starizona Nexus focal reducer, and ZWO Duo-Band filter.
Gain: 200 for lights and flats, 1 for biases.
30 Biases (.001 seconds).
40 Flats (automated in N.I.N.A.).
Binning set to 1x1.
Flats taken using a white T-Shirt stretched over the front of the telescope and exposed to the light from my storage shed.
Bortle 5 skies.
Moon: 19.8 days old.
I had to process this in Siril from files saved to an external drive, as trying to process it on my 1TB laptop resulted in a failure due to lack of storage space. The initial three-hour capture resulted in 73GB of files. After the preprocessing was completed in Siril, the files in the Process directory exceeded 900GB!

The antennae are visible, but quite faint. I think that I will give this another try, setting the gain to 300, and capturing with the ZWO Duo-Band filter, and then once again, without the filter, to see what difference in increase in gain makes.

NGC 4038 and 4039 - The Antennae Galaxies

The Antennae Galaxies are undergoing a galactic collision. These two galaxies are known as the Antennae Galaxies because the two long tails of stars, gas and dust ejected from the galaxies as a result of the collision resemble an insect's antennae. The tails are very faint in this image.

About 1.2 billion years ago, the Antennae were two separate galaxies. 900 million years ago, the Antennae began to approach one another. 600 million years ago, the Antennae passed through each other. 300 million years ago, the Antennae's stars began to be released from both galaxies. Today the two streamers of ejected stars extend far beyond the original galaxies, resulting in the antennae shape.

Within 400 million years, the Antennae's nuclei will collide and become a single core with stars, gas, and dust around it.

(Adapted from