NGC 281, also known as IC 11, SH2-184, and more commonly known as the “Pacman Nebula,” is an emission nebula located 9,100 light-years away in the constellation of Cassiopeia.

This image results from 8 hours of narrowband data and is rendered in the SHO Hubble Palette.

The initial data was collected over two nights ending on October 22nd.  That collection cycle was interrupted due to illness.  Three of the projects whose data was collected on those nights had enough integration that I could process the images.  However, this one was still pretty short for the S2 filter.  So I waited until I had a chance to add to the data set.  Finally, on November 23, we had a clear night, and I was able to add about 3 hours more data to this project. 

This image was shot on my Astro-Physics 130mm f/8.35 APO telescope platform, which uses a ZWO ASI2600MM-Pro camera, and is supported by an IOptron CEM60 Mount. 

When I looked at the data for this project, I discovered a very strange artifact that I have never seen on this platform before - in fact, I have not seen it on any platform.  I ended up having a series of concentric circles located in the lower-left corner of the image and a strange mottled noise across the rest of the image field.  This pattern was not seen in the flats or the darks and was evident in every sub and master regardless of filters.  It was also constant across all three evenings where data was collected. 

In dealing with this, I ended up having the background sky much darker than I would have preferred, but all is not bad, as I think it does add to the "Snap" and the drama of the image. 

This is also the first image I tried using Bill Blanshan's new SHO Normalization script on. 

All details are in the post below. 

The full story behind this image, along with a detailed processing walkthrough, can be found at:
https://cosgrovescosmos.com/projects/ngc281-pacman-nebula-11-23-22

A video of the blink analysis for this data is also available if interested:
https://youtu.be/tiAUlvqpU-A

Finally, a video on my YouTube channel provides a high-level view of the processing strategy for this image:
https://youtu.be/vDXuTLz2Wdc

Please consider liking and following my fledgling YouTube channel!  ( If nothing else you can laugh at my attempts to learn the video side of things!)

Thanks for looking!

Pat