The Cygnus Loop/Veil Nebula

The Cygnus Loop is a large supernova remnant that goes by many names. At nearly 3 degrees across, this is a very large object and many sub-structures have their own names, such as the East and West Veil Nebula (the whole structure is also sometimes called the Veil Nebula) or Pickering’s Triangle. In addition to the colloquial names, there are at least 6 objects in this image with catalog designations.

I took this image while camping in Moab, UT from a very dark (probably Bortle 2/3) location. Unfortunately I was under a time crunch, so I only got part of a night worth of data and the moon was almost full. I attempted to counteract the moonlight by using the Optolong l-eXtreme filter, which is a dual narrowband cut filter, meaning it blocks all light except for two very specific wavelengths. It’s not a perfect solution, but it works pretty well. Especially since this target is primarily emitting light on the OIII and HA wavelengths, which are the wavelengths allowed by the filter.

Because of the size of the target and the gear I had at the time, I took this image as a two-part mosaic that was later combined into a single image. I think this was a very successful mosaic (sometimes the seam can be fairly hard to get rid of), especially given how little time was spent collecting light and the mediocre quality of the camera I was using.