The data for this LRGB image are from Telescope.live (
https://telescope.live/home) and consist of LRGB-filtered images totaling 4.7 hours of exposure. Approximately 20% of the original data were discarded due to poor quality. The telescope system consisted of a Planewave CDK24 equipped with a QHY 600M Pro camera. The system is located in Chile. The data were processed using Pixinsight and to a lesser degree, Photoshop. When I processed this image I noticed a conspicuous green object near PGC39002 and thought it was a camera artifact. But then began to wonder and found it in another Astrobin image (
https://www.astrobin.com/b05iz1/B/). It was identified as SN2024exw (
https://www.rochesterastronomy.org/sn2024/sn2024exw.html). Why is it green? I found the object in all filters (RGB) and I did calibrate the image using SPCC. I did not use SCNR.
I would not have noticed the SN if it had not been for the green color! I think I know what happened. The green color is an artifact of statistical noise rejection during stacking in Pixinsight. The problem arose because I was mixing images from March (no SN) and May (SN). For blue and red, there were more frames from March. Thus, the system rejected the SN pixels, which can be seen in the red and blue masters. But for the green data, I had more images from May where the SN was present, there was no rejection, and the object showed up green in the RGB.
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