Object name: NGC6992
The Cygnus Loop is a huge bubble of gas blown by a supernova some 15,000 years ago about 2600 light-years from us according to the HST website. APOD says 7500 years ago and 1400 light years distant. Other sources give other figures but the ratio stays rather constant. In other words, this one is still rather unknown as to distance and time though the trend is making it smaller and nearer. It was said to be over 100,000 years old when I first learned of it nearly 60 years ago! Various parts of it go by various common names. Veil, Witches Broom, Pickering's Triangle and others. It also has several NGC and IC numbers. You need a system with over a three degree field of view to see the entire bubble, 6 times the size of the full moon. Like most bubbles, it is the edges that are the easiest to see as the gas there is thicker from our perspective. The portion in my frame is of the northeastern edge of the bubble known as NGC 6992. My field is way too small for even that so I have just part of it. I'd need at least four such images to cover all of NGC 6992. That was my intent last summer but weather prevented it from happening. It took several nights just to get this one part.