Sharpless 279, better know as the Running Man of Orion is an HII region and bright nebulae including a reflection nebula located in Orion. It is the northernmost part of the asterism known as Orion’s Sword, lying 0.6° north of the famous M42 nebula.
This dataset comprises over 10 hours of RGB data, with no Moon. On this target I switched to NINA (I was using SGP before) and used the Hocus Focus NINA plugin, which greatly improved focus stability over the imaging sessions. I also changed to 5mn subs for RGB (I was doing mostly 1 or 2mn in the past) and extended the overall integration time to 10.5 hours, with over 40 sub for each color. The goal was to go deeper, reduce noise, and have enough subs to allow efficient oversampling through drizzle integration if needed. The subs are littered with satellite trails, but the dataset is large enough to allow even a small amount of sigma clipping to remove them. The bright stars have very prominent diffraction spikes, and this image is a very good dataset to continue working on my Radon diffraction spike attenuation algorithm (I ported it to Python 3 recently and I am working on a few modifications to better handle both mono and color images).
One thing I noticed at processing, so way too late, was that the brightest star saturated, making star reduction challenging. I have since implemented more QCs to avoid reoccurrence of this on future dataset.
For the processing I went minimalist: PixInsight Batch Preprocessing, Dynamic Background Extraction, Multiscale Denoise, Histogram, a bit of Saturation Boost, 180 rotation so the Running man is not upside down and finally the Dark Structure Enhance script. I plan to revisit for diffraction spike attenuation and star reduction.
Here is the raw data: