Whispers of a Stellar Death - SNR G65.3+5.7

This is a four-panel mosaic of SNRG65.3+5.7 in HOO with RGB stars. It is a vast but very faint supernova remnant located in the constellation Cygnus. It has low surface brightness against a crowded star field. First identified in 1977, portions of the remnant had earlier been listed as Sh2-91, Sh2-94, and Sh2-96. Spanning roughly 230 light-years in diameter and estimated to be around 27,500 years old, it rivals the Veil Nebula in apparent size but is far more difficult to observe due to its faintness. I captured around 169 hours of data across four panels from May to Sept, 2025 from my backyard.
A higher resolution of this image can be seen at: https://www.deepspacebackyard.com/

Telescope: Askar FRA300 pro
Mount: ZWO AM3
Camera: ZWO2600MM Pro
Filters: Antlia 2.5nm Ha, O3 and ZWO R, G, B
Acquisition:
Ha: 86h20m
O3: 77h
RGB: 6h
Total Integration: 169h20m
Processed in PixInsight and Photoshop

I used Weighted Batch Preprocessing script in Pixinsight to calibrate and stack each filter data. I used matching dark, flats and dark flats as calibration frames. After stacking and registration, I used Dynamic Background Extraction to remove sky glow and then stretched each master file and combined them in HOO pallete to show this Supernova remnant. I then added broadband RGB stars. This is a four-panel mosaic to show the entire SNR.