Date Posted: 2/21/2020
Date Taken: 10/27/2019 thru 12/19/2019
Scope: Planewave CDK 12.5 f/8, 2541mm
Camera: SBIG STL-11000 with Astrodon Tru-Balance E-Series Gen2 filters
Temp: -25C
Mount: Losmandy Titan
Guiding: On-axis via ONAG-XM and SX UltraStar at 2541mm. FocusLock real-time focus for focusing.
Exposure: LRGB 336:158.25:165:174.75 Luminance unbinned, RGB binned 2x2.
Calibrated and Stacked with CCDStack2; RGB combine and DDP with MaximDL. Mosaic created using Microsoft ICE. Processed with CS4.

This is a 4-panel mosaic of M42. Details on individual panels are below. I shot 4 panels, using 2 minute subs. In addition, I shot a set of 15-second subs of the Triangulum region to layer in and show additional detail.

I got burned by Starlink while shooting this. There were *LOTS* of satellite trails in the upper portion of this image. There are still faint traces; they are parallel to and just below the
horizontal diffraction spike from Iota Orionis, the bright blue star. For the top right panel, the trails were in 40 of 42 subs. That panel was shot within a week of the Nov 19 Starlink launch.

For unknown reasons MS-ICE wouldn't combine the 4 DDP-stretched luminance panels; but I was able to combine panels 1 & 2, then 3 & 4 separately, and then combine the two results to get the final composite. For the color, I did the RGB combine for each panel, then a DDP stretch, then the combine with MS-ICE. Due tothe high dynamic range of the image, balancing the colors from the background through the brightest areas was challenging, and there are still some artifact remaining as a result.

Finally, I layered in a separately-processed LRGB image of the central Trapezium region with PS, to being out more detail.

I undertook this because I have a large blank space on one wall, and I thought this might look good there. This image is flipped vertically, purely because I thought it looked better aesthetically.

Not that anyone is interested, but individual panel details are below:

Panel 1 (bottom left):
Date Taken: 10/27/2019, 11/1/2019
Exposure: 84:42:44:46 All subs 2 min.

Panel 2 (top left):
Date Taken: 11/2/2019, 11/3/2019
Exposure: 84:40:40:44 All subs 2 min.

Panel 3 (bottom right):
Date Taken: 11/5/2019, 11/20/2019
Exposure: 72:32:34:36 All subs 2 min.

Panel 4 (top right):
Date Taken: 11/24/2019, 11/25/2019
Exposure: 82:38:40:42 All subs 2 min.

Central Region:
Date Taken: 12/19/2019
Exposure: 14:6.25:7:6.75. All subs 15 seconds.