Date Uploaded: 3/21/2025
Date Taken: 11/19/2017, 11/23/2017, 11/24/2017
Scope: Planewave CDK 12.5 f/8, 2541mm
Camera: SBIG STL-11000 with Astrodon Tru-Balance E-Series Gen2 filters
Temp: -15C
Mount: Losmandy Titan
Guiding: On-axis via ONAG-XM and SX UltraStar at 2541mm; FocusLock real-time focus software.
Exposure: LRGB 270:135:135:130 All subs 5 min. Luminance unbinned, RGB binned 2x2.
Calibrated and Stacked with CCDStack2; RGB combine and DDP with MaximDL. Processed with CS4.

NGC 1931, a.k.a. the Fly Nebula, is a mix of emission and reflection nebulae surrounding a star cluster. The cluster is young, estimated to be about 2 million years old. It is located about 7500 light years away in Auriga.

This is a tweak of an older image, using StarXterminator for better stretching of the nebula, and StarShrink to reduce star sizes.